GEOLOGY AND PALEONTOLOGY OF PALOS - Pubs Warehouse

UNITED STATES DEPARTMENT OF THE INTERIOR 

Harold L. Ickes, Secretary 

GEOLOGICAL SURVEY 

W. E. Wrather, Director 

Professional Paper 207 

GEOLOGY AND PALEONTOLOGY OF PALOS 

i 

VEKDES HILLS, CALIFORNIA 

BY 

W. P. WOODRING, M. N. BRAMLETTE, AND W. S. W. KEW 

UNITED STATES 

GOVERNMENT PRINTING OFFICE 

WASHINGTON : 1946 

For sale by the Superintendent of Documents, U. S. Government Printing Office, Washington 25, D. C. 

Price $1.50

Abstract ________________________________________ 

Introduction _______________________________________ 

Scope of report. ___-_-________-___---_--________ 

Field work__ _ _._____________________^_. ________ 

Acknowledgments. ___--_-____-___----_-________ 

Early history of region. _-_____--_-_-_-_-_.______ 

Name used for the hills.-. _ ___-_-_.---_____-_____ 

Bibliography. . _________________________________ 

Geography __________-__--____-_____---_-___-____ 

Geographic relations.----.-..----------.-------- 

Surface features. ________-_-_-_---_-_---___-_-__ 

Land use.__. ___._--_--__-_---- -----_ -------- 

Stratigraphy and paleontology. _ __--___-------_-____ 

Outline of stratigraphy. _________________________ 

Jurassic (?) system.... ._____...__..__-______.-__ 

Franciscan (?) schist. ___.._-___---_---._____ 

Distribution and lithology ___---.--______ 

Age__... ._...----.. -..._--------.----. 

Miocene series _ ____________-_---------_-_.____ 

Monterey shale.... ______-_-__ _______.______ 

General relations. --__-___------_-_-__._ 

Lithology. _.__.____. _ _». __-_------______ 

Fossils ___ _________---'_ __---_-_-__.___ 

Altamira shale member.. _ _______________ 

Lower part, including Portuguese tuff 

bed... ___.-._---.--------.-----. 

Stratigraphy and lithology- ______ 

Portuguese Canyon area_____ 

Miraleste area.... __________ 

Bluff Cove area ___ _______ 

Fossils ___ -.____- ___ _ . _ 

Foraminifera____ ___________ 

Middle part, including Miraleste tuff 

bed. ___--____-_--__.....----_.__ 

Stratigraphy and lithology _ ______ 

Bluff Cove- Malaga Cove area. 

Bluff Cove-Lunada Bay area. 

Lunada Bay-Point Vicente 

Altamira Canyon-Portuguese 

Canyon area. ----__-___-_ 

Agua Negra Canyon area. . _ _ 

George F Canyon-Miraleste 

Canyon area. ____________ 

Miraleste-San Pedro Hill area. 

San Pedro area. ____________ 

Point Fermin area. _________ 

Whites Point area_ _________ 

Fossils. _..._-- _ ________ _ ___ 

Foraminifera. ______________ 

Upper parti _ _____________________ 

Stratigraphy and lithology- ______ 

Malaga Cove area. _________ 

Lunada Bay area. __________ 

Crest of hills...---..--- __ 

North slope of hills. ___--___ 

San Pedro area. ____________ 

Point Fermin-Whites Point 

Foraminifera. _____-____-_-_ 

Mollusks -__._- _____--_-__. 

Valmonte diatomite member. ____________ 

Stratigraphy and lithology- _ _________ 

Malaga Cove area. __.__.____-_. 

Synclinal areas in western part of 

hills... -__-----------_:_----- 

North slope. of hills. ____________ 

San Pedro area. ________________ 

CONTENTS 

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Stratigraphy and paleontology Continued. 

Miocene series: Continued. . 

Monterey shale Continued. 

Valmonte diatomite member Continued. 

Page 

Fossils. .____...__.._.___..___. 

Foraminifera- __________________' 

Mollusks. _____________________ 

Vertebrates- ___________________ 

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Malaga mudstone member.i__l__________ 37 

Stratigraphy an d lithology ___________ 

Malaga Cove area. _____________ 

North slope of hills_.____-.._._._ 

San Pedro area..________'_______ 

Fossils...__--------_-_------_-_. 

Foraminifera_ __________________ 

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Environment suggested by fossils._______. 

Age and correlation.___'__._______-______ 

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Pliocene series_________--__---_______-_---___- 40 

Repetto siltstone.__________________________ 

General features._______________________ 

Stratigraphy and lithology-______^-_____. 

Malaga Cove__.____________________ 

Ravine west of Hawthorne Avenue 

near Walteria____________________ 

Lomita quarry-Palos Verdes Drive 

East area._______________________ 

Fossils___--_--_-_-_-____---;_-_ -__- 

Foraminifera- _____________________ _ 

Mollusks. _________________________ 

Environment suggested by fossils.________ 

Age and correlation. ____________________ 

Pleistocene series.______________________________ 

Principal subdivisions.______________________ 

Lomita marl, Timms Point silt, and San Pedro 

sand ____________________________________ 


Stratigraphic relations_____________ 

General character and distribution.... 

Type region of Stratigraphic units.._._ 

Stratigraphy and lithology___--____-_____ 

Deadman Island..._________________ 

Timms Point.._-_-______.___.___.__ 

Central San Pedro._________________ 

Northwestern San Pedro-_-_-__-_____ 

Eastern part of Gaffey anticline. _____ 

Hilltop quarry and nearby localities. __ 

Lomita quarry and nearby localities_ 

Western part of Gaffey anticline. _____ 

North border of hills between Bent 

Spring Canyon and Hawthorne 

Avenue...------____.--__________ 

North border of hills between Hawthorne 

Avenue and Malaga Cove___ 

Malaga Cove ___________________ 

Marine terrace deposits __________________ 


Marine terrace deposits older than Palos 

Verdes sand______________-_______.__. 

Stratigraphy and lithology_---___-___ 

Twelfth terrace..:________-___._. 

' Ninth terrace__.___________'__i_ 

Eighth terrace.................. 

Sixth terrace.__________________ 

Fifth terrace.__________________ 

Fourth terrace_____-----____._ 

Third terrace_._.___________.. 

' . Second terrace________________ 

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IV CONTENTS 


Pleistocene series Continued. 

Marine terrace deposits Continued. 

Palos Verdes sand_ _____________________ 

General features. ___________________ 

Stratigraphy and lithology _ __________ 

Deadman Island________________ 

Southern San Pedro _ __________ 

Northern San Pedro ___ ________ 

Gaffey anticline and syncline east 

of Palos Verdes Drive North. __ 

Gaffey anticline west of Palos Verdes 

Drive North.'. ____________ 

North border of hills between Bent 

Spring Canyon and Hawthorne 

Foraminif era_ 

Corals _ ____ 

Echinoids- _ __ 

Bryozoa. ____ 

Brachiopods. 

Mollusks_ _-- 

Chitons 

North border of hills between Haw 

thorne Avenue and Malaga 

Malaga Cove 

Pelecypods_ -_____---_-___-_______-_ 

Barnacles.-. ------ _____________________ 

Decapod crustaceans-----.---.. _________ 

Birds .-..---- __----___---__--_------ 

Marine mammals. __--__-___-_-___l_____ 

Land mammals---------------.----.---- 

Calcareous algae__ _ _____________________ 

Environment suggested by fossils_____-_______ 

Geographic distribution of Pleistocene mol- 

lusks that are still living- ______________ 

Depth distribution of Pleistocene mollusks 

that are still living--. __________'_______ 

Lomita marl*. __________________________ 

Timms Point silt. ______________________ 

San Pedro sand__-____--_____--_____-_-- 

Marine terrace deposits older than Palos 

Verdes sand-__-_--------------_-__-_- 

Palos Verdes sand. _-__--___-_-_____-.-_ 

Age and correlation. ________________________ 

Correlation within Palos Verdes Hills____-- 

Lower Pleistocene _______ 

Upper Pleistocene- _____ 

Glacial-interglacial assignments. 

Mixed faunal fades _ ________________ 

Effects of changes in outline of coast. _ 

Effects of local temporary changes in 

ocean temperature. _______________ 

Possible changes in geographic and 

depth range since Pleistocene time. 

Interpretation of temperature facies in 

terms of possible glacial and inter- 

glacial assignments________________ 

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ILLUSTRATIONS 


Pleistocene series Continued. 

Age and correlation Continued. 

Correlation with other areas_-___________ 

Lower Pleistocene______----___.___ 

Los Angeles Basin subsurface sec 

tion. ________________________ 

Signal Hill______. ______________ 

Santa Monica. ._____-____-__-__ 

Ventura Basin________________ 

Santa Barbara and Rincou Point- 

San Francisco Peninsula. ________ 

Upper Pleistocene...________________ 

San Diego and nearby localities.__ 

Capistrano Beach___________.___ 

Los Angeles Basin subsurface sec 

tion. _ _______________________ 

Signal Hill-.-.._-_-----_--..._. 

Playa Del Rey______--_-_-_____ 

Santa Monica._________________ 

Localities northwest of Santa Mon- 

Pleistocene to Recent series________________-______ 

Nonmarine terrace cover__________._ .-_______ 

Stratigraphy and lithology________________ 

Fossils. ________________________________ 

Pleistocene (?) series.___________________________ 

Stream terrace gravel.____-_-___--_---_-__._ 

Recent series.--__----___-_________________-____ 

Dune sand_________________________________ 

Alluvium. __-_-___-_-______-___________---- 

Basaltic rocks of Miocene age________________________ 

Structure.-___-_--__-_---_-_-______________________ 

Structural history._____________________________ 

Miocene.__________________________^_______ 

Late Pliocene deformation______-__-__---____ 

Middle Pleistocene deformation_______________ 

Late Pleistocene and Recent deformation._____ 

Regional relations._____________ _________________ 

General features._______________________________ 

North border of hills____.____'___________________ 

Northwestern part of hills.______________________ 

Bluff Cove and nearby areas._______---_------___ 

Area between western San Pedro and Palos Verdes 

Drive East___________________________________ 

Whites Point area._____________________________ 

Remainder of hills._____________________________ 

Physiography _____________________________'_________ 

Marine terraces_______________ ________________ 

Rolling upland_____-_______________-_____-____- 

Minor physiographic features._!__________________' 

Landslides._ _---_-_-_______________-_-_____ 

Dune sand_________________________________ 

Events since emergence of lowest terrace_____---_-_ 

Relations to nearby areas._____________-_-----__- 

Mineral resources.-_______________j_________________ 

Oil possibilities-________________________________ 

Diatomite._-_-_-_-_____--___________----______ 

Sand and gravel-_______________________________ 

Other products.____-____-________-__---__---_-_ 

Fossil localities____________^._______________________ 

Index _______________---_______________-___----___- 

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PLATE 1. Geologic map and sections of Palos Verdes Hills, Los Angeles County, Calif. ___---__________--___-------- In pocket 

2. Relief map of California showing location of Palos Verdes Hills ____________-_____-'_______--__--------_--_ 18 

3. Sections of Altamira member of Monterey shale in Palos Verdes Hills_________________-______-_---_--_--_--- 18 

4. View on south slope of Palos Verdes Hills looking northward up Altamira Canyon and tributaries,.---------.--- 18 

5. View on south coast of Palos Verdes Hills looking westward across Inspiration Point and Portuguese Point to 

Long Point---.-.....--..--------------- ...-.---------- r ----------------------------------------- 19 

6. Altamira member of Monterey shale and basalt_. ------------------------------------------------------- 34 

7. Altamira member of Monterey shale.___________________________-_--_-_-------_---__--_----------------- 34 

8. Phosphatic and bituminous shale in upper part of Altamira member of Monterey shale at Lunada Bay_____-___- 34 

9. Blue-schist sandstone in upper part of Altamira member of Monterey shale at Point Fermin._________-_---_--. 34 

10. Miocene and Pliocene formations'.-_-____________________-___-_---___------__---_---_---------------_--- 34 

11. Valmonte diatomite and Malaga mudstone members of Monterey shale at Malaga Cove______________-_---_--_ 34 

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CONTENTS 

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PLATE 12. Miocene, Pliocene, and Pleistocene formations at Malaga Cove.---____-____--_-----_____-_-__--___-________ 50 

13. Sections of Pleistocene strata in Palos Verdes Hills______________________________________________________ 50 

14. Geologic map of northeastern San Pedro____________________________________________________________ In pocket 

15. Pleistocene formations in San Pedro..______________l___________-________-_-____________________________ 50 

16. Microscopic organic constituents in unit 6a of Lomita marl in canyon west of Hilltop quarry___--__-_--________ 51 

17. Lomita marl_________________________________________________________________________________________ 58 

18. Pleistocene formations on north border of Palos Verdes Hills.______________________________________________ 58 

19. San Pedro sand in Sidebotham No. 1 sand pit___-_-_____-______------___-______-!________________________ 58 

20. Pleistocene formations on north border of Palos Verdes Hills.____----_______________-______________________ 59 

21. Geologic map of north border of Palos Verdes Hills adjoining Hawthorne Ayenue____-___-_-_______________ In pocket 

22. Topographic map of Palos Verdes Hills showing distribution and designation of Pleistocene marine terraces and 

terrace profiles.___-___--_---_-___----_--_-------------------_-_--------------_----_--____-______ In pocket 

23. Cut on Palos Verdes Drive south, near Point Vicente, showing platforms of fourth and third terraces and inter 

vening sea cliff.__________----_-_-_---___-___-_-_-_--_--_---_--__---___-_------_______--____________ 114 

24. Terrace deposits and structural and physiographic features of the Palos Verdes Hills __________________ _'__-^.___ 114 

25. Airplane view on west coast of Palos Verdes Hills looking from Bluff Cove southwestward toward Lunada Bay__^_ 114 

26. View on west coast of Palos Verdes Hills looking southwestward frpm Malaga Cove_----_______.______________ 114 

27. Rolling upland along crest of Palos Verdes Hills._____._-_--_-----_-__---_--____--_-__-__.________________ 114 

28. Miocene mollusks from middle part of Altamira member of Monterey shale..._-__----_____---________________ 128 

29-31. Pleistocene mollusks from Lomita marl._____-___________-.._-___-_---_-_-_-------_,___-_-_____-_r_.____ 129-131 

32, 33. Pleistocene mollusks from Timms Point silt.___________________________________________________________ 132, 133 

34. Pleistocene mollusks from San Pedro sand- ____________--___-____i--____-________________________________ 134 

35. Pleistocene mollusks from marine deposits on fourth and second terraces and from Palos Verdes sand._..__-______- -135 

36, 37. Pleistocene mollusks from Palos Verdes sand__-_-_---___-----_-_---_-_-------_-----------___-_-_-_-____ 136, 137 

1. Sketch map of Los Angeles Basin and borders showing location of Palos Verdes Hills with reference to other 

geographic features .___-_-_-_-_---__----_-___-_.--__---------___---___---..--------____---_--___- 9 

2. Generalized stratigraphic sections in western part of Los Angeles Basin and its borders.._------___-_____-__-_ 10 

3. Generalized stratigraphic section in Palos Verdes Hills. __-. ....-.--...-..-...-.:..,..........-............ 11 

4. Chart showing relation between lithologic units and foraminiferal zones in Monterey shale of Palos Verdes Hills. _ 15 

5. Sea cliff at Bluff Cove ______________________________________________________________________________ 18 

6. Minor isoclinal anticline exposed in sea cliff a quarter of a mile southwest of mouth of Malaga Canyon ________ 20 

7. Sea cliff at Malaga Cove.__._.-__-_--__--_--__-__--.-_-___-_-_-.____'__---___-__._--_---._____-.-_-___ 34 

8. Valmonte diatomite and Altamira shale members of Monterey shale in sea cliff near mouth of Malaga Canyon. _ _ _ 34 

9. Repetto siltstone in northern syncline at Malaga Cove ________________________________________________ 41 

10. Chart showing inferred relations of Lomita marl, Timms Point silt, and San Pedro sand. ____________________ 44 

11. Lomita marl on southwest face of Hilltop quarry_____________.___._________________________.____________ 49 

12. Contact between Lomita marl and Miocene mudstone on east bank of Agua Negra Canyon. _________________ 53 

13. Pleistocene strata in fifth ravine west of Hawthorne Avenue____-_________________________________________ 53 

14. Fan-shaped anticline at Whites Point___________________________________'______________________'_______ 112 

15. Marine terrace platforms, marine deposits, and nonmarine cover.__________________________________________ 114 

16. Stream profiles showing hanging valleys__.____-__--..________-_---._____________________ .--_______.___ 116

GEOLOGY AND PALEONTOLOGY OF PALOS VERDES HILLS, CALIFOKNIA 

BY W. P. WOODRING, M. N. BKAMLETTE, AND W. S. W. KEW 

ABSTRACT 

Stratigraphy and paleontology. A rnetamorphic basement and 

formations of Miocene, Pliocene, and Pleistocene age are exposed 

in the Palos Verdes Hills. The Miocene and later deposits, about 

3,000 feet thick, are much thinner than strata' of the same age in 

the adjoining Los Angeles Basin and along the north border of 

the basin. 

The oldest rocks are schists, assigned doubtfully to the 

Franciscan, and altered basic igneous rocks. Quartz-sericite 

schist, quartz-talc schist, and quartz-glaucophane schist are the 

most common rock types. The Franciscan (?) schist is considered 

of doubtful Jurassic age but may be older. 

The Miocene strata are assigned to the Monterey shale, which 

has an exposed thickness of about 2,000 feet and is divided into 

three mapped local members in ascending order the Altamira 

shale, the Valmonte diatomite, and the Malaga mudstone. The 

Altamira, the thickest of the three members, is divided into lower, 

middle, and upper parts, characterized, respectively, by the 

prevalence of silty shale, cherty shale, and phosphatic shale. The 

Valmonte consists chiefly of diatomite and diatomaceous shale; 

tlie Malaga is made up principally of mudstone containing 

Radiolaria. The Altamira shale member includes two named 

tuffs a thick bentonitic tuff named the Portuguese tuff bed and 

a thin pumice tuff designated the Miraleste tuff bed. The 

Monterey overlaps the schist basement northward. According 

to the foraminiferal faunal zones represented, the Monterey of 

the Palos Verdes Hills is of late middle to late upper Miocene 

age, the division between middle and upper Miocene being 

between the middle and upper parts of the Altamira. Mollusks 

from sandstone resting on schist include several warm-water 

genera not found heretofore in the Coast Ranges. 

The lower Pliocene Repetto siltstone overlies disconformably the 

Monterey shale. It consists of glauconitic foraminiferal siltstone 

having a maximum exposed thickness of about 150 feet. Much 

thinner than the Repetto of the Los Angeles Basin, it includes, 

nevertheless, the equivalent of a considerable part of the basin 

section, according to the foraminiferal zones. The Repetto con 

tains deep-water fossils. 

Lower Pleistocene strata cropping out on the north and east 

borders of the hills rest unconformably on the Repetto siltstone 

and lap up on different parts of the Monterey shale. They con 

sist of 350 to 600 feet of sand, silt, and calcareous strata the 

San Pedro sand, the Timms Point silt, and the Lomita marl, 

respectively. Wherever the Lomita marl is found, it is at the 

base of the section. The Timms Point silt is either at the base of 

the section or overlies the Lomita marl. The Lomita marl and 

Timms Point silt are interpreted as essential chronologic equiva 

lents of each other and of the lower part of the San Pedro sand 

at localities where the marl and silt are absent. 

Marine deposits on the platforms of marine terraces are 

assigned to the upper Pleistocene. The marine deposits on the 

extensive lowest terrace the only terrace deposits named 

constitute the Palos Verdes sand. The Palos Verdes sand rests 

unconformably on lower Pleistocene strata or on older formations. 

The Pleistocene strata are exceptionally fossiliferous, For- 

aminifcra and mollusks being most abundant in the lower Pleisto 

cene and mollusks in the upper Pleistocene terrace deposits. 

The mollusks indicate several depth associations in the lower 

Pleistocene, ranging from shallow-water to moderate-depth 

(50 to 100 fathoms). Moderate-depth associations are prevalent 

in the Lomita marl, are the only associations recognized in the 

Timms Point silt, and are represented locally in the San Pedro 

sand. A rock-cliff and tide-pool association is characteristic of 

terrace deposits older than the Palos Verdes sand. An associa 

tion indicating protected shallow water is prevalent in the Palos 

Verdes sand. 

The marine Pleistocene strata are assigned to that epoch 

because their faunas are more modern than those of Coast Range 

Pliocene formations. The age assignments of the subdivisions 

of the Pleistocene are somewhat arbitrary. Though the Pleisto 

cene deposits are presumably contemporaneous with Pleistocene 

glacial and interglacial stages, glacial-intergiacial assignments 

based on the faunas are so involved, owing to possible effects 

produced by other factors, that such assignments are 

questionable. 

Miocene igneous rocks. Basaltic rocks, generally in the 

form of sills, penetrate the lower and middle parts of the Alta 

mira shale member of the Monterey but are not known to occur 

in younger strata; that is, they are not known to be younger 

than middle Miocene. 

Structure. The structure of the Palos Verdes Hills is in 

general anticlinal. A deep-seated fault, not exposed at the 

surface, extends probably along the north border of the hills, 

and another may lie off shore to the south. The strongest 

deformation took place during the upper Pliocene, less marked 

deformation during the middle Pleistocene, and weaker deforma 

tion near the end of the upper Pleistocene. The effects of middle 

and upper Pleistocene deformation, other than uplift that took 

place repeatedly during upper Pleistocene time, are visible 

only along the north border of the hills, where the lower Pleisto 

cene strata are moderately or strongly deformed and the upper 

Pleistocene lowest terrace platform and its deposits are mildly 

or moderately deformed. 

In general the structure is relatively simple with the excep 

tion of a few areas the north border and adjoining northwestern 

part of the hills, an area between San Pedro and Palos Verdes 

Drive East, and a small area near Whites Point where the 

strata have been deformed by small folds and faults. 

Physiography. Thirteen main marine terraces considered of 

upper Pleistocene age are recognized. They are most clearly 

defined on the windward west slope, on part of the windward 

south slope, and on the lower part of the leeward east slope. 

Along the north border of the hills the lowest terrace has no 

longer the usual physiographic features of a terrace, owing to 

deformation since the terrace was formed. In the Palos Verdes 

Hills the effects on terrace development of lowering and rising 

sea level produced by Pleistocene glaciation and deglaciation 

are unrecognized. \ 

The crest and upper slopes of the hills are characterized by a 

rolling upland rerpesenting an old erosion surface of moderate 

relief thought to have been formed during the period between the 

early Pliocene submergence and the late Pleistocene submergence. 

Mineral resources. Oil in commercial quantities has not been 

found so far in the Palos Verdes Hills. Eighteen wells have been 

drilled to depths greater than about 1,000 feet in the hills and 

close to the north border. Most of the wells located in the main 

part of the hills reached the schist basement at depths of about 

900 to 3,900 feet below sea level. Wells drilled along and near 

the north border encountered greatly sheared steeply dipping 

Pliocene and Miocene formations, and in two wells part of the 

stratigraphic succession is reported to be inverted. The oil 

possibilities have not been tested thoroughly, however, at locali 

ties where the structure is favorable or where overlap may be 

effective. 

Diatomite from the Valmonte diatomite member of the 

Monterey shale is mined and processed at a locality near the 

north border of the hills. The Valmonte diatomite is present 

along the north and east slopes, but material of the quality of 

that mined is not found there generally in commercial quantity. 

Sand and gravel from the San Pedro sand are mined at several 

localities along the north border of the hills. There are extensive 

deposits of such material in that area. 

INTRODUCTION 

SCOPE OF REPORT 

During the early years of the present century a general 

study of the geology of California oil fields was under 

taken under the auspices of the Geological Survey by 

G. H. Eldridge and after his death by Ralph Arnold.

GEOLOGY AND PALEONTOLOGY OF PALOS VERDES HILLS, CALIFORNIA 

As part of this program a report J was issued on the 

geology of the east end of the Santa Monica Mountains, 

the adjoining hills in the city of Los Angeles, and the 

Puente Hills all along the north border of the Los 

Angeles Basin. (See fig. 1.) At the time when this 

program was started development of the oil fields was 

carried on by small companies, generally with the 

advice of practical oil prospectors. The intervening 

years have witnessed the rapid growth of the oil industry 

and the development of modern oil geology. As oil 

development progressed in the Los Angeles Basin the 

geology of the basin and its borders was studied inten 

sively by many geologists. Inasmuch, however, as the 

results of the work of commercial geologists are not 

available for general use, it appeared desirable .for the 

Geological Survey to continue the investigations begun 

in this area by Eldridge and Arnold. In 1926 a report 2 

was issued on the Puente Hills and adjoining parts of 

the Sarita Ana Mountains, and in a later publication 3 

the geology of the eastern part of the Santa Monica 

Mountains was described. 

The present report on the geology of the Palos Verdes 

Hills is part of the series of publications dealing with 

the geology of areas within and bordering the Los Ange 

les Basin. It describes the geology, paleontology, and 

mineral resources of the Palos Verdes Hills. The 

strata that crop out in the hills are penetrated in oil 

fields in the southern part of the Los Angeles Basin. 

Special emphasis is devoted to data that may aid in 

studying the subsurface section in the basin. 

The illustrations of fossils from the different forma 

tions may be useful to both field geologists and labo 

ratory paleontologists. According to the experience of 

California geologists, the illustrations of fossils in 

early reports of the Geological Survey on California 

oil fields are as useful now as at the time when the 

reports were issued, despite changes in paleontologic 

and stratigraphic nomenclature. 

The Palos Verdes Hills include the San Pedro district, 

which has become a classic region in California geology 

as a result of Arnold's monograph 4 on the Pleistocene 

paleontology. About 150 collections of Pleistocene 

mollusks were made during the field work on which 

the present report is based. It was planned to identify 

a sufficient number of these collections to show the 

facies and geographic differentiation of the fossils in 

the different Pleistocene stratigraphic units. This 

plan was abandoned, however, for the identification, 

of about 500 species of mollusks would have involved 

much work, and such a laborious undertaking would 

have delayed unduly completion of the report. Se 

lected species were identified to serve as a basis for a 

discussion of the faunas. The omission, of long lists of 

Pleistocene mollusks is not a great loss, as Arnold's 

collections were exhaustive and other paleontologists 

have contributed to the Pleistocene paleontology of 

the San Pedro district since the publication of Arnold's 

monograph. Arnold's collecting was limited, how 

ever, to a small area along the water front. One 

lithologic and faunal unit (Lomita marl) is not repre- 

1 Eldridge, G. H., and Arnold, Ralph, The Santa Clara Valley, Puente Hills and 

Los Angeles oil districts, southern California: U. S. Geol. Survey Bull. 309, pp. 102-198, 

pis. 10-24, figs. 12-17. 1907. 

2 English, W. A., Geology and oil resources of the Puente Hills region, southern 

California: U. S. Geol. Survey Bull. 768,110 pp., 14 pis., 3 figs., 1926. 

s Hoots, H. W., Geology of the eastern part of the Santa Monica Mountains, Los 

Angeles County, Calif.: U. S. Geol. Survey Prof. Paper 165, pp. 83-134, pis. 16-34, 

figs. 7, 8,1931. 

«Arnold, Ralph, The Paleontology and stratigraphy of the marine Pliocene and 

Pleistocene of San Pedro, Calif.: California Acad. Sci. Mem., vol. 3, 420 pp., 37 pis., 

1903. (Reprint Leland Stanford Jr. Univ., Contr. Biol. Hopkins Seaside Lab., No. 

31,1903.) 

sented along the water front and consequently was not 

known by Arnold. Many species not recorded by 

Arnold have been found in that unit and in others. 

FIELD WORK 

The field work on which this report is based was 

started by W. S. W. Kew in 1921-22 and was continued 

by him at intervals until 1924. The geology of the 

area controlled at that time by the Palos Verdes Syn 

dicate, comprising about the western two-thirds of the 

hills, was mapped on a topographic base (scale, 1:9,600; 

contour interval, 5 feet) supplied by the company. 

The geology of the remainder of the area was mapped 

on the topographic map of the Redondo quadrangle 

enlarged from a scale of 1:62,500 to a scale of 1:31,250. 

The geologic map of the entire area was compiled on the 

same enlarged map of the Redondo quadrangle. Kew 

completed the first draft of a report in 1925 after his 

resignation from the Geological Survey. 

The topographic map' available for publication at 

that time was unsuitable on account of the small scale, 

and the project was laid aside. By 1928 maps pre 

pared on a scale of 1:24,000 by the Geological Survey 

in cooperation with Los Angeles County were avail 

able for the entire area (San Pedro Hill, Wilmington, 

and Torrance quadrangles). During the summer of 

1930 the geology of the area lying outside the original 

holdings of the Palos Verdes Syndicate was mapped by 

W. P. Woodring on the new topographic maps enlarged 

to a scale of 1:12,000. In view of difficulties en 

countered in transferring the geology from one topo 

graphic map to another and in view of recent advances 

in stratigraphy, it later became evident that remapping 

of the entire area on a scale of 1:12,000 was desirable. 

This work was carried on by Woodring and M. N. 

Bramlette during the summer of 1933 and by Woodring 

during the summer of 1935. During the field season 

of 1933 particular attention was given to the Miocene 

Monterey shale, which had been studied previously by 

Bramlette at many other localities in the Coast Ranges. 

The scale used in mapping is adequate for work of 

moderate detail. The results attained, however, can 

not be regarded as more than a detailed reconnaissance, 

at least in the area underlain by Miocene strata. In 

that area, which embraces the greater part of the hills, 

exposures are generally poor, except along some of the 

deep canyons and along the sea cliff. Distinctive 

lithologic units seem to be rare in the Miocene section, 

strata evidently of the same age change in facies from 

place to place, and minor structural complications 

prevent generally a determination of stratigraphic 

position on a basis of regional structure. Neverthe 

less, the broad features of the Miocene stratigraphy 

and the succession of foraminiferal zones appear to be 

satisfactorily established. 

It is difficult to show adequately on the geologic map 

(pi. 1) the distribution of rock types along the sea 

cliff, for at many places the cliff, is vertical or almost 

vertical. Areas covered by talus along the cliff are 

not shown on the map, as it would be confusing rather 

than helpful to plot them. 

Owing to more urgent matters, the preparation of 

the report was delayed until 1939. In the meantime 

a preliminary account 5 of the Miocene stratigraphy 

s Woodring, W. P., Bramlette, M. N., and Kleinpell, R. M., Miocene stratigraphy 

and paleontology of Palos Verdes Hills, Calif.: Am. Assoc. Petroleum Geologists 

Bull., vol. 20, No. 2, pp. 125-149, 3 figs., 1936.

and paleontology and a general account 6 of the fossils 

from the Pleistocene marine terraces were published. 

ACKNOWLEDGMENTS 

The Miocene Foraminifera, on which the age assign 

ments and correlations of the Miocene strata are based, 

wore determined by R. M. Kleinpell while he was .on 

the staff of the Geological Survey. S. G. Wissler, of 

the Union Oil Co. of California, furnished notes based 

on an examination of a series of foraminiferal samples 

from the lower Pliocene Repetto siltstone at Malaga 

Cove. The late 11. D. Reed, of the Texas Co. (Cali 

fornia), offered much assistance dealing particularly 

with the Pleistocene calcareous strata now assigned 

to the Lpmita marl. Hampton Smith, of the same 

organization, gave many helpful suggestions. A sec 

tion of the Lomita marl in the canyon adjoining 

Hilltop quarry was measured with the assistance of 

J. M. Hamill, B. G. Laiming, and Mr. Reed. H. L. 

Driver, G. C. Ferguson, H. W. Hoots, and Mr. Wissler 

assisted in measuring and sampling the Repetto silt- 

stone at Malaga Cove. Photographs were furnished 

by U. S. Grant, K. E. Lohman, Mr. Reed, and officials 

of the Palos Verdes Estates. 

During construction, of the Whites Point tunnel 

through the eastern part of the Palos Verdes Hills 

during 1935 and 1936 J. R. Schultz, then a graduate 

student at the California Institute of Technology, 

studied the geology of the tunnel under the auspices of 

the Geological Survey. Special acknowledgment is 

duo A. M. Rawn, assistant chief engineer of Los 

Angeles County Sanitation Districts, and officials of 

the construction companies for facilities and courtesies 

that greatly aided Mr. Schultz's studies. The results 

of his work are included in this report. 

During part of the time when this report was written, 

office and laboratory space in the quarters of the 

Division of Geological Sciences of the California 

Institute of Technology at Pasadena was available 

through the kindness of Prof. J. P. Buwalda. 

EARLY HISTORY OF REGION 

Juan Rodriguez Cabrillo was the first white navigator 

to explore the coast of California. During his voyage 

up the coast in 1542 he sailed past San Pedro Bay, 

winch he named Bahia de los Fumos, from the smoke 

of Indian fires. 7 Late in 1602 Sebastian Vizcaino 

explored this part of the California coast. Many of 

the names he gave to coastal features are still in use. 

One of Vizcaino's ships evidently entered San Pedro 

Bay, which is designated Ensenada de San Andr6s on 

a chart based on the results of his voyage. 8 In the 

manuscript coast-pilot written in 1603 by Franco de 

Bplafios and Father Antonio de la Ascension, two of 

Vizcaino's assistants, the bay is called Ensenada de 

San Pedro the first known usage of that designation. 

Tho bay and the Palos Verdes Hills are well described 

Woodrlng, W. P., Fossils from the marine Pleistocene terraces of the San Pedro 

Hills, Cnlif.: Am. Jour. Sci., 6th scr., vol. 29, pp. 292-305, 1 flg., 1935. 

7 Wagner, H. 11., Spanish voyages to tho northwest coast of America in the sixteenth 

century: California Hist. Soc. Special Pub. 4, p. 334, 1929; The cartography of the 

northwest const of America to the year 1800, vol. 1, p. 412, Berkeley, 1937. 

Other writers have identified Santa Monica Bay as the Bahia de los Fumos. See 

Davldson, Ocorco, An examination of some of tho early voyages of discovery and 

exploration on tno northwest coast of America from 1539 to 1603: U. S. Coast and 

Geodetic Survey Ropt. Supt., 1880, app. 7, p. 190,1887; Bolten, H. E., Spanish explo 

ration In tho Southwest, 1542-1706: Original narratives of early American history, 

p. 7, New York, 1910. 

> Wagner, If. R., op. clt. (California Hist. Soc. Special Pub. 4), p. 402; The cartog 

raphy of the northwest coast of America to the year 1800. vol. 1, p. 412, Berkeley, 1937. 

For a reproduction of part of the chart see Bancroft, H. H., History of California, 

vol. 1 (Works of Hubert Howc Bancroft, vol. 18), p. 100, San Francisco, 1884. 

692787 45- 

INTRODUCTION 

in the following extract from Wagner's translation 9 of 

the manuscript: 

From the Punta de la Conversion [Concepci6n] the coast 

trends east for more than fourteen leagues, very rough and 

rugged without any trees to a point which the land makes 

extending north-south, and with a hill, of medium height bare 

on top which from afar looks like an island. To the east is a 

very good ensenada with shelter from the northwest, west, and 

southwest winds. It is named the "Ensenada de San Pedro" 

in 34^°, and in it there is a small island. Here are friendly 

Indians. 

During the colonial period the open roadstead at 

San Pedro was used as a port for San Gabriel Mission, 

founded in 1771, and the village of Los Angeles,'founded 

in 1781. The hide warehouse described by Dana 10 in 

chapter 14 of "Two years before the mast" was the 

first building erected at the port. It stood on the bluff 

about midway between Point Fermin and Timms 

Point. Point Fermin was named by Vancouver during 

his voyage of 1793 in honor of Fermin de Laus6n, who 

succeeded Junipero Serra as head of the Franciscan 

missions in California. 

The Palos Verdes Hills were used as grazing land for 

cattle and horses during the colonial period. The entire 

area of the hills, with the exception of a narrow strip 

along the east coast reserved for public use, and part of 

the adjoining Los Angeles Plain were included in the 

Rancho de los Palos Verdes, embracing an area of 

about 32,000 acres. 11 Jose" Loreto Sepulveda and Juan 

Sepulveda, sons of Jose" Dolores Sepulveda, received a 

provisional grant to this land in 1827 and a final grant 

from Governor Pio Pico in 1846. The elder Sepulveda 

was killed by Indians in 1824 during a journey to 

Monterey to petition for a patent. In 1882 the land was 

transferred from the Sepulveda family in a debt 

settlement. 

NAME USED FOB THE HILLS 

On current maps the hills are generally designated 

the San Pedro Hills. Most of the local residents, how 

ever, use the name "Palos Verdes Hills," and that name 

has been used by several writers and cartographers. In 

view of local usage and to avoid confusion with the 

name "San Pedro Hill," which is in usage for the highest 

hill in full view from the city of San Pedro, the United 

States Board on Geographical Names has adopted the 

name "Palos Verdes Hills." 12 This designation is par 

ticularly fitting, as it commemorates the name of the 

colonial ranch. The name Palos Verdes is said to have 

been based on willows growing along the small stream 

flowing southward into the present Bixby Slough. 13 

BIBLIOGRAPHY 

Publications dealing with the geology, paleontology, 

and geography of the Palos Verdes Hills are included 

in the following bibliography. 'Abstracts covering the 

same ground as later publications are omitted. 

1855. Trask, J. B., Report on the geology of the Coast Moun 

tains: California Legislature, App. to Jours., 6th sess. 

S. Doc. 14, 95 pp. 

Bituminous shale [Monterey shale] of San Pedro 

district briefly described (pp. 24-26). 

Wagner, H. R., op. cit. (California Hist. Soc. Special Pub. 4), p. 438, 1929. For 

a description of the manuscript see Wagner's publication, pp. 381-382. 

10 Dana, R. H., Two years before the mast, a personal narrative of life at sea, pp; 

118-119, New York, 1840. 

" For a brief summary of the history of the Palos Verdes Rancho see Robinson, 

W. W., Ranches become cities, pp. 18-25, Pasadena, 1939. 

i* U. S. Board on Oeog. Names, Decisions rendered between July l, 1934, and June 

30, 1935,p. 19, 1936. 

is Robinson, W. W., op. cit., p. 19.


1855. Conrad, T. A., Note on the Miocene and post-Pliocene 

deposits of California, with descriptions of two new 

fossil corals: Philadelphia Acad. Nat. Sci. Proc., vol. 7, 

p. 441. (Reprinted in U. S. Geol. Survey Prof. Paper 

59, p. 172, 1909.) 

Five species of post-Pliocene [Pleistocene] mollusks 

are listed from localities "near Santa Barbara and San 

Pedro." 

1855. Blake, W. P., Preliminary geological report [Williamson's 

reconnaissance in California]: In U. S. Pacific R. R. 

Expl., U. S. 33d Gong., 1st sess., H. Ex. Doc. 129, 80 pp. 

Bituminous shale [Monterey shale] of San Pedro 

district mentioned (p. 69). 

1855. Conrad, T. A., Report on the fossil shells collected in 

California by Wm. P. Blake, geologist of the expedition 

under the command of Lieutenant R. S. Williamson, 

United States Topographical Engineers: Idem, app.', 

pp. 9-20. (Reprinted in U. S. Geol. Survey Prof. 

Paper 59, pp. 163-171, 1909.) 

Twelve species of mollusks described from "Recent 

formation" at San Pedro .[Palos Verdes sand]. 

1855. Blake, W. P., Remains of the mammoth and mastodon 

in California: Am. Jour. Sci., 2d ser., vol. 19, p. 133. 

Mammoth tooth from San Pedro [evidently from 

Palos Verdes sand]. 

1855. Trask, J. B., [Description of fossil shells from the Tertiary 

deposits of Santa Barbara and San Pedro, California]: 

California Acad. Nat. Sci. Proc., vol. 1, pp. 41-43. 

(2d ed., pp. 40-42, 1873.) 

Description of Fusus robustus and Fusus rugosus from 

strata at San Pedro [presumably San Pedro sand or 

Timms Point silt]. 

1856. Blake, W. P., Observations on the physical geography and 

§ eology of the coast of California from Bodega Bay to 

an Diego: U. S. Coast and Geodetic Survey Rept. 

Supt. 1855, app. 65, pp. 376-398. 

Geology of San Pedro district described (pp. 393-395). 

1856. Trask, J. B., Description of three new species of the genus 

Plagiostoma from the Cretaceous rocks of Los Angeles: 

California Acad. Nat. Sci. Proc., vol. 1, p. 86, 1 pi. 

(2d ed., pp. 93-94, pi. 3, 1873.) 

Description of Plagiostoma pedroana, P. annulatus, 

and P. truncata from strata on east coast of Palos Verdes 

Hills considered Cretaceous [upper part of Altamira 

shale member or Valmonte t diatomite member of 

Monterey shale]. 

1857. Blake, W. P., Geological report [Williamson's reconnaissance 

in California]: U. S. Pacific R. R. Expl., vol. 5, 

pt. 2, 370 pp., 11 pis., maps, sections. 

Description of strata at and near landing in San Pedro 

(pp. 129-130), of post-Pliocene deposits [Palos Verdes 

sand] and fossils near mouth of Los Angeles River 

(p. 186), including illustration of mammoth molar, and 

of Miocene siliceous shale (pp. 178-179). Analysis of 

siliceous rock from San Pedro (p. 341). 

1857. Conrad, T. A., Descriptions of the fossil shells: Idem, app., 

art.-2, pp. 317-329, pis. 2-9. 

Same data as in preliminary report (1855) with 

addition of illustrations. ],- U. jp \~ %. c \* ^-'j^. \& \ g 

1857. Antisell, Thomas, Geological report [Parke's surveys in 

California and near thirty-second parallel]: Idem, vol. 7, 

pt. 2, 204 pp., 14 pis., 2 maps, 1856 (1857). 

Two sections of terrace deposits at San Pedro (p. 118), 

one of which is shown graphically (pi. 5, fig. 4). Bituminous 

rock at San Pedro mentioned (p. 77). 

1865. Gabb, W. M., Description of new species of marine shells 

from the coast of California: California Acad. Nat. Sci. 

Proc., vol. 3, pp. 182-190. 

Description of, three species from post-Pliocene at 

San Pedro [evidently Timms Point silt at Deadman 

Island]. 

1866. Gabb, W. M., Tertiary invertebrate fossils: California 

Geol. Survey, Paleontology, vol. 2, sec. 1, pt. 1, pp. 

1-38, pis. 1-13. 

Description of 6 species of mollusks from post- 

Pliocene at San Pedro, one of which (Conchocele disjuncta) 

is specifically recorded from Deadman Island 

[Timms Point silt]. 

1869. Gabb, W. M., Tertiary invertebrate fossils: Idem, sec. 1, 

pt. 2, pp. 39-63, pis. 14-18. 

Pecten pedroanus, considered Cretaceous by Trask, is 

assigried to upper Miocene (p. 60), as in this report. 

Three additional species of mollusks are recorded from 

post-Pliocene at San Pedro. 

1869. Gabb, W. M., Synopsis of the Tertiary invertebrate 

fossils of California: Idem, sec. 1, pt. 3, pp. 65-124. 

Earliest comprehensive record of fossils from post- 

Pliocene [Pleistocene], of San Pedro 86 species of 

mollusks and one echinoid, many of which were not 

recorded earlier. Conchocele disjuncta is the only 

species that has definite locality record Deadman 

Island [Timms Point silt]. 

1888. Cooper, J. G., Catalogue of California fossils: California 

Min., Bur., 7th Ann. Rept. State Mineralogist, pp. 

223-308. 

Includes records of Pleistocene fossils from San Pedro. 

1892. Dall, W. H., and Harris, G. D., Correlation papers; 

Neocene: U. S. Geol. Survey Bull. 84, 349 pp., 3 pis., 

43 figs. 

Three formations are recognized on Deadman Island 

(p. 216), "the uppermost of which [presumably San 

Pedro sand] is certainly Pleistocene, while the others are 

Neocene, and the middle layer [Timms Point siltl 

probably Pliocene." 

1893. Lawson, A. C., The post-Pliocene diastrophism of the 

coast of southern California: California Univ. Dept. 

Geol. Bull., vol. 1, pp. 115-160. 

Marine Pleistocene terraces of Palos Verdes Hills are 

described (pp. 122-128). Fossiliferous strata assigned 

to lower Pleistocene in present report considered 

Pliocene. 

1894. Cooper, J. G., Catalogue of California fossils, pt. 3, Addi 

tions to the catalogue of Californian fossils obtained 

since 1888: California Min. Bur. Bull. 4, pp. 23-33. 

Includes records of Pleistocene fossils from San Pedro. 

1895. Ashley, G. H., Studies in the

1902. Arnold, Delos, and Arnold, Ralph, The-marine Pliocene 

and Pleistocene stratigraphy of the coast of southern 

California: Jour. Geology, vol. 10, pp. 117-138, pis. 

1-5, 6 figs. 

Pleistocene strata of San Pedro district are described 

and terras "lower San Pedro series" and "upper San 

Pedro series" are proposed (pp. 119-129). [For re 

marks concerning stratigraphic nomenclature see fol 

lowing entry.] 

1903. Arnold, Ralph, The paleontology and stratigraphy of the 

marine Pliocene and Pleistocene of San Pedro, Calif.: 

California Acad. Sci. Mem., vol. 3, 420 pp., 37 pis. 

(Reprint Leland Stanford Jr. Univ., Contr. Biol. Hop- 

kins Seaside Lab., No. 31, 1903.) 

Monographic treatise on stratigraphy and paleon 

tology of Pleistocene strata exposed on San Pedro water 

front and Deadman. Island. Includes descriptions of 

4 species of corals, 3 echinoids, undetermined Bryozoa, 

2 brachiopods, 395 mollusks, a barnacle, a crab, and 

a sting ray, many of which are figured. Arnold's Plio 

cene is Tirnrns Point silt of this report, his lower San 

Pedro series is San Pedro sand, and his upper San 

Pedro series is Palos Verdes sand and nonmarine deposits 

on first terrace. 

1904. Rivers, J. J., Descriptions of some undescribed fossil 

shells of Pleistocene and Pliocene formations of the 

Santa Monica Range: Southern Calif. Acad. Sci. Bull., 

vol. 3, pp. 69-72. 

Description and only record of "Chrysodomus" arnoldi 

from Arnold's Crawfish George's locality. 

1906. Arnold, Ralph, The Tertiary and Quaternary pectens of 

California: U. S. Geol. Survey Prof. Paper 47, 264 pp., 

53 pis., 2 figs. 

Lists of fossils from Pliocene of Deadman Island 

[Timms Point silt] and from tlie "San Pedro formation" 

[San Pedro sand and Palos Verdes sand] (pp. 30-37). 

Systematic part includes descriptions and illustrations 

of the pectens. 

1906. Raymond, W. J., The west American species of Pleurotoma, 

subgenus Genota: Nautilus, vol. 20, pp. 37-39, pi. 2. 

Includes records of Pleistocene forms from San Pedro 

district. 

1907. Barfcsch, Paul, The west American mollusks of the genus 

Triphoris: U. S. Nat. Mus. Proc., vol. 33, pp. 249-262, 

pi. 16. 

Includes Pleistocene species from San Pedro district. 

1909. Dall, W. TI., and Bartsch, Paul, A monograph of west 

American Pyramidellid mollusks: U. S. Nat. Mus. Bull. 

68, 258 pp., 30 pis. 


1911. Bartsch, Paul, The Recent and fossil mollusks of the 

genus Alabina from the west coast of America: U. S. 

Nat. Mus. Proc., vol. 39, pp. 408-418, pis. 61-62. 


1911. Bartsch, Paul, The Recent and fossil mollusks of the genus 

Cerithiopsis from the west coast of America: Idem, vol. 

40, pp. 327-367, pis. 36-41. 



Bittium from the west coast of America: Idem, pp. 383- 

414, pis. 51-58. 



Alvania from the west coast of America: Idem, vol. 41, 

pp. 333-362, pis. 29-32. 


1912. Bagg, R. M., Jr., Pliocene and Pleistocene Foraminifera 

from southern California: U. S. Geol. Survey Bull. 

513, 153 pp., 28 pis., 3 figs. 

Description of 105 species and varieties of Foramini 

fera from "Pliocene" at Timms Point [Timms Point 

silt], 39 of which are figured from San Pedro material. 

. Discussion of paleoecology. 

1912. Miller, L. H., Contribution to avian paleontology from 

the Pacific Coast of North America: California Univ. 

Dept. Geol. Bull., vol. 7, pp. 61-115, 1912. 

Three species of birds listed from Arnold's upper 

San Pedro (p. 115). 

1913. Rivers, J. J., A new species of Bathyloma from the upper 

Pleistocene of San Pedro, Calif.: Southern California 

Acad. Sci. Bull., vol. 12, p. 29, unnumbered pi. 

" Bathytoma" clarkiana, based on worn imperfect 

specimen, evidently a form of Megasurcula carpen- 

teriana. 

INTRODUCTION 

1913. Prutzman, P. W., Petroleum in southern California: 

California Min. Bur. Bull. 63, 430 pp., unnumbered 

illustrations, maps. 

Wells drilled for oil in and near Palos Verdes Hills 

described (pp. 327-329), and locations shown on small- 

scale map of southern California (in pocket). 

1914. Martin, Bruce, Descriptions of new species of fossil Mol- 

lusca from the later marine Neocene of California: 

California Univ. Dept. Geol. Bull., vol. 8, pp. 181-282, 

pis. 19-22. 

Description and only record of Tritonofusus riversi 

from Timms Point (p. 190). 

1914. Rivers, J. J., A new form of Bathyloma from the upper 

Pleistocene of San Pedro, Calif.: Nautilus, vol. 28, 

pp. 64-65, pi. 3, figs. B, C. 

Same data as in Rivers, 1913. 

1914. Miller, L. H., Bird remains from the Pleistocene of San 

Pedro, Calif.: California Univ. Dept. Geol. Bull., vol. 

8, pp. 31-38. 

Sixteen species of birds from Arnold's upper San 

Pedro at his lumber yard locality [locality 113 of present 

report.] 

1914. McLaughlin, R. P., and Waring, C. A., Petroleum indus 

try of California: California Min. Bur. Bull. 69, 519 

pp., 78 figs., 13 unnumbered illustrations, map folio of 

IS^pls. 

Oil possibilities in Palos Verdes Hills briefly discussed 

(pp. 366-367). Map folio plate 1 includes 5 species of 

Pleistocene mollusks from San Pedro; plate 2 includes a 

small-scale geologic map of Palos Verdes Hills. 

1917. Bartsch, Paul, A monograph of west American melanellid 

mollusks: U. S. Nat. Mus. Proc., vol. 53, pp. 295-356, 

pis. 34-49. 


1919. Chace, E. P. and E. M., An unreported exposure of the 

San Pedro Pleistocene: Lorquinia, vol. 2, No. 6, pp. 

41-43. 

List of mollusks from marine deposits on second 

terrace near Point Fermin [locality 94 of present report], 

where chitons were exceptionally abundant; discussion 

of paleoecology and age. 

1919. Smith, J. P., Climatic relations of the Tertiary and Quater 

nary faunas of the California region: California Acad. 

Sci. Proc., 4th ser., vol. 9, pp. 123-173, pi. 9. 

Includes discussion of cool-water aspect of Arnold's 

Pliocene (pp. 150-151) and lower San Pedro (pp. 

136-137) faunas, and of warm-water aspect of Arnold's 

upper San Pedro fauna (pp. 137-138). 

1919. Nelson, J. W., and others, Soil survey of the Los Angeles 

area, Calif.: U. S. Bur. Soils Field Operations Advance 

Sheets, 78 pp., 3 pis., map. (18th Rept., 1916, pp. 

2347-2420, 3 pis., map, 1921.) 

Includes Palos Verdes Hills. 

1920. Kew, W. S. W., Cretaceous and Cenozoic Echinoidea of 

the" Pacific coast of North America: California Univ. 

Dept. Geol. Bull., vol. 12, pp. 23-236, pis. 3-42, 5 figs. 


1921. Oldroyd, T. S., New Pleistocene mollusks from California: 

Nautilus, vol. 34, pp. 114-116, pi. 5, 

Three forms of mollusks from Arnold's lower San 

Pedro, one of which (Vermetus nodosus) is not considered 

in Oldroyd's 1924 account. 

1921. Vander Leek, Lawrence, Petroleum resources of Califor 

nia, with special reference to unproved areas: California 

Min. Bur. Bull. 89, 186 pp., 6 pis., 12 figs., 6 unnumbered 

photographs. 

Oil possibilities in Palos Verdes Hills discussed 

(p. 141). 

1922. Berry, S. S., Fossil chitons of western North America:. 

California Acad. Sci. Proc., 4th ser., vol. 11, pp. 399-526, 

pis. 1-16, figs. 1-11. 

Includes Pleistocene species from San Pedro district, 

the largest number (350 specimens of 15 species and 

varieties) being from the Chaces' chiton bed locality 

on the second terrace near Point Fermin. 

1922. Jordan, D. S., Some sharks' teeth from the California 

Pliocene: Am. Jour. Sci., 5th ser., vol. 3, pp. 338^-342, 

3 figs. 

Description of shark's teeth, assigned to 4 species, 

from Pleistocene of Palos Verdes Hills [presumably 

Lomita marl]. 

1922. Kellogg, Remington, Pinnipeds from Miocene and Pleis 

tocene deposits of California: California Univ. Dept. 

Geol. Sci. Bull., vol. 13. pp. 23-132 6 figs. 

Undetermined seal (Phoca sp. B, p. 120) recorded 

from Arnold's upper San Pedro.


1923. Jordan, D. S., ami Hannibal, Harold, Fossil sharks and 

rays of the Pacific slope of North America: Southern 

California Acad. Sci. Bull., vol. 22, pp. 27-63, 65-68, 

11 pis., 4 figs. 

Shark t'eeth, assigned to 7 specie^, from Lomita 

quarry [Lomita marl], a ray from Oldroyd's Nob Hill 

locality [San Pedro sand], and a ray from Arnold's 

upper San Pedro [Palos Verdes sand]. Marine and land 

vertebrates from Lomita quarry. 

1923. Hanna, G. D., Results of preliminary examination of 

seven samples of sediments from near Lomita: Idem, 

p. 64. 

Paleoecology and age of fossils from Lomita quarry. 

1923. Canu, Ferdinand, and Bassler, R. S., North American 

later Tertiary and Quaternary Bryozoa: U. S. Nat. 

Mus. Bull. 125, 302 pp., 47 pis., 38 figs. 

Includes species from Pleistocene of Deadman Island 

[evidently Timms Point silt]. 

1924. Oldroyd, T. S., The fossils of the lower San Pedro fauna 

of the Nob Hill cut, San Pedro, Calif.: U. S. Nat. Mus. 

Proc., vol. 65, art. 22, 39 pp., 2 pis. 

Stratigraphy, paleontology, and paleoecology of a 

locality in San Pedro now destroyed. Records 242 

species and varieties of mollusks, 22 of which are 

described as new. 

1924. Oldroyd, I. S., Description of a new fossil species of a clam 

of the genus Crassatellites: Southern Calif. Acad. Sci. 

Bull., vol. 23, p. 10, 1 fig. 

"Crassatellites" lomitensis from Pleistocene beds near 

Lomita [Lomita marl]. 

1924. Woodford, A. O., The Catalina metamorphic facies ofthe 

Franciscan series: California Univ. Dept. Geol. Sci. 

Bull. vol. 15, pp. 49^68, pis.'5-7, 2 figs. 

Includes description of schist basement in Palos 

Verdes Hills and its rock types. 

1925. Cushman, J. A., and Hughes, D. D., Some later Tertiary 

Cassidulinas of California: Cushman Lab. Foraminiferal 

Research Contr., vol. 1, pp. 11-16, pi. 2. 

Includes description of species from Timms Point 

and Lomita quarry. 

1925. Stock, Chester, Cenozoic gravigrade edentates of western 

North America, with special reference to the Pleistocene 

Megalonychinae and Mylodontidae of Rancho La Brea: 

Carnegie Inst. Washington Pub. 331, 206 pp., 47 pis., 

120 figs. 1 

List of land mammals from Arnold's upper San Pedro 

and brief discussion of relations to Rancho La Brea 

fauna (pp. 118-119). 

1925. Woodford, A. O., The San Onofre breccia, its nature and 

origin: California Univ. Dept. Geol. Sci. Bull., vol. 15, 

pp. 159-280, pis. 23-35, 11 figs. 

Description of blue-schist sandstone and breccia in 

Miocene strata at Point Fermin and record of fossils 

(pp. 210-211). 

1926. Kew, W- S. W., Geologic and physiographic features in 

the San Pedro Hills, Los Angeles County, Calif.: Oil 

Bull., vol. 12, No. 5, pp. 513-518, 590, 3 figs. 

General account of geology and physiography. 

1926. Rathbun, M. J:, The fossil stalk-eyed Crustacea of the 

Pacific slope of North America: U. S. Nat. Mus. Bull 

138, 155 pp., 39 pis. 

Descriptions of 25 species from Pleistocene at San 

Pedro, 6 of which are new. Those from Oldroyd's 

Nob Hill lower San Pedro locality represent San Pedro 

sand. Horizon of others not designated. 

1927. Cushman, J. A., and Grant, U. S., IV. Late Tertiary and 

Quaternary Elp'hidiums of the west 'coast of North 

America: San Diego Soc. Nat. History Trans., vol. 5, 

No. 6, pp.> 69-82, pis. 7, 8. 

Includes record of Elphidium crispum? from "Plio 

cene" [Pleistocene] of San Pedro district. 

1927. Galloway, J. J., and Wissler, S. G., Pleistocene Foraminifera 

from the Lomita Quarry, Palos Verdes Hills, 

Calif.: Jour. Paleontology, vol. 1, pp. 35-87, pis. 7-12. 

Description of 79 species and varieties of Foraminifera 

from calcareous strata [Lomita marl] at Lomita quarry. 

1927. Galloway, J. J., and Wissler, S. G., Correction of names of 

Foraminifera: Idem, p. 193. 

New names for homonyms proposed in preceding 

account. 

1927. Hay, O. P., The Pleistocene of the western region of 

North America and its vertebrated animals: Carnegie 

Inst. Washington Pub. 322B, 346 pp., 21 maps, 12 pis. 

Arnold's lower San Pedro is assigned to Nebraskan 

glacial stage and his upper San Pedro to Aftonian 

interglacial stage (pp. 166-174). 

1927. Kellogg, Remington, Fossil pinnipeds from California: 

Idem, Pub. 346, pp. 25-37, 8 figs. 

Description of sea lion radius (Zalophus sp.?) from 

Arnold's upper' San Pedro at his lumber yard locality 

(pp. 33-35) [locality 113 of present report]. 

1928. Hanna, G. D., The age of the diatom-bearing shales at 

Malaga Cove, Los Angeles County, Calif.: Am. Assoc. 

Petroleum Geologists Bull., vol. 12, pp. 1109-1111. 

The diatoms are considered upper Miocene and 'are 

thought to furnish conclusive evidence that the material 

accumulated in shallow water. [It is not known whether 

the diatoms are from Valmonte diatomite member or 

Malaga mudstone member of the Monterey shale. A 

shallow-water depositional environment for either is 

doubtful.] 

1928. Reed, R. D., A siliceous shale formation from southern 

California: Jour. Geology, vol. 36, pp. 342-361, 4 figs. 

Petrology and organic constituents of nonforamini- 

feral siliceous shale [Valmonte diatomite member and 

Malaga mudstone member of Monterey shale] and 

foraminiferal rock [Repetto siltstone] at Malaga Cove. 

1929. Crickmay, C. H., On a new pelecypod, Calyptogena 

gibbera: Canadian Field Naturalist, vol. 43, p. 93, 1 fig. 

This species is from the lower part of the strata of 

Deadman Island now assigned to Timms Point silt. 

1929. Crickmay, C. H., The anomalous stratigraphy of Dead- 

man's Island, Calif.: Jour. Geology, vol. 37, pp. 617-638. 

Stratigraphy and paleontology of Pleistocene forma 

tions of Deadman Island, with special reference to 

temperature facies of different zones. 

1929. Nicholson, G. F., Variations in levels, 1929 to 1927, in 

Los Angeles harbor: Seismol. Soc. America Bull., vol. 

19, pp. 200-205, 3 figs. 

Relative uplift of as much as 0.2 foot, attributed to 

moverrent along inferred fault. 

1930. Miller, Loye, Further bird remains from the upper San 

Pedro Pleistocene: Condor, vol. 32, pp. 116-118, fig. 

45. Ten species from Arnold's upper San Pedro at his 

lumber yard locality, including the extinct diving goose 

Chendytcs lawi. 

1931. Clark, Alex, The cool-water Timms Point Pleistocene 

horizon at San Pedro, Calif.: San Diego Soc. Nat. 

History Trans.,. vol. 7, No. 4, pp. 25-42, 2 figs. 

Stratigraphy and paleontology of strata at Timms 

Point, for which term "Timms Point" is proposed. 

List of 137 species of mollusks, 2' brachiopods, 13 

Bryozoa, an undetermined barnacle, an undetermined 

crab, and a fish tooth. 

1931. Grant, U. S., IV, and Gale, H. R., Catalogue of the marine 

' Pliocene and Pleistocene Mollusca of California: San 

Diego Soc. Nat. History Mem., vol. 1, 1,036 pp., 32 

pis., 15 figs. 

Part I (by Gale) includes discussion of stratigraphy 

and temperature facies of marine Pleistocene formations 

in San Pedro region and assignment of them to glacial 

and interglacial stages (pp. 40-45, 60-76). Part II 

assembles records of marine mollusks from those forma 

tions and includes illustrations of some species based 

on material from that region. 

1931. Miller, J. M., The landslide at Point Firmin, Calif.: Sci. 

Monthly, vol. 32, pp. 464-469, 5 figs. 

Attributed to seaward sliding along slippery shale 

on flank of anticline. 

1931. Reed, R. D., Petrology of the calcareous beds of San 

Pedro Hills, Calif, (abstract): Geol. Soc. America 

Bull., vol. 42, pp. 310-311, 1931. 

Petrology of calcareous strata assigned in present 

report to Lomita marl. 

1932. Hadding, Assar, The pre-Quaternary sedimentary rocks 

of Sweden; IV, Glauconite and glauconitic rocks: 

Lunds Geol.-Mineralog. Inst. Meddel., No. 51, 174 pp., 

73 figs. 

Analysis of glauconite from Pleistocene strata at 

San Pedro (p. 124) [presumably from Lomita marl]. 

1932. Woodrin^ W. P., San Pedro Hills: 16th Internat. Geol. 

Cong. Guidebook 15, pp. 34-40, figs. 4H3. 

Geologic features of an excursion in Palos Verdes 

Hills. Designations for Miocene units superseded in 

later accounts. 

1932. Hoots, H. W., Excursion in Los Angeles Basin and Santa 

Monica Mountains: Idem, pp. 43-48, pi. 9. 

Geologic features of an excursion including Palos 

Verdes Hills (p. 45).

1933. Davis, W. M., Glacial epochs of the Santa Monica Moun 

tains, Calif.: Geol. Soc. America Bull., vol. 44, pp. 

1041-1133, pis. 40-56, 26 figs. 

Marine terraces of Palos Verdes Hills mentioned (p. 

1105). 

1933. Liyingston, Alfred, Jr., and Putnam, W. C., Geological 

journeys in southern California: Los Angeles Junior Coll. 

Pub. 1, 104 pp., 56 unnumbered illustrations. 

Includes an enthusiastic account of geologic features 

in Palos Verdes Hills (pp. 17-21). 

1933. Reed, R. D., Geology of California, 355 pp., 60 figs., 

Tulsa, Am. Assoc. Petroleum Geologists. 

Petrology and other features of Miocene (pp. 195- 

196), Pliocene (pp. 238-239), and Pleistocene (pp. 258- 

261) formations of Palos Verdes Hills. 

1934. Eckis, Rollin, South Coastal Basin investigation; Geology 

and ground water storage capacity of valley fill: Cali 

fornia Dept. Public Works, Water Resources Div. Bull. 

45, 279 p., 24 pis., 6 maps. 

Contains much information that has direct or indirect 

bearing on geologic history of Palos Verdes Hills, 

especially in discussion of Pleistocene formations 

and history (pp. 48-62). Geologic map (scale 

1:142,560) is largest scale geologic map now available 

of Los Angeles Basin and borders, including Palos 

Verdes Hills. 

1934. Howe, M. A., Eocene marine algae (Lithothamnieae) 

from the Sierra Blanca limestone: Geol. Soc. America 

Bull., vol. 45, pp. 507-518, pis. 52-56. 

Mesophyllum(f) recorded from Lomita quarry (pp. 

515, 517). 

1934. Leypoldt, Harry, Earth movements in California deter 

mined from apparent variation in tidal datum planes: 

Seismol. Soc. America Bull., vol. 24, pp. 63-68, 3 figs. 

Records of tide gages in outer and inner harbors at 

San Pedro' indicate relative subsidence in inner harbor 

from 1922 to 1928, relative uplift from 1928 to 1930, 

and relative subsidence beginning in 1930. 

1935. Miller, Loye, New bird horizons in California: California 

Univ. at Los Angeles, Pub. Biol. Sci., vol. 1, No. 5, 

pp. 73-80, 2 figs. 

Description of three sea birds from Miocene strata in 

Palos Verdes Hills [Valmonte diatomite member of 

Monterey shale] and record of a small cetacean. 

1935. Smith, Hampton, Origin of some siliceous Miocene rocks 

of California (abstract): Geol. Soc. America Proc., 

1934, p. 334. 

Siliceous cement of cherty shales in Palos Verdes 

Hills thought to have been derived principally from 

decomposition of bentonitic clay and perhaps of volcariic 

ash. 

1935. Woodring, W. P., Fossils from the marine Pleistocene 

terraces of the San Pedro Hills, Calif.: Am. Jour., Sci., 

5th ser., vol. 29, pp. 292-305, 1 fig. 

Preliminary account of marine terraces and fossils. 

1936. Raup, H. F.. Land-use and water-supply problems in 

southern California; market gardens of the Palos 

Verdes Hills: Geog. Rev., vol. 26, pp. 264-269, 4 figs. 

Factors controlling raising of vegetable crops without 

irrigation. 

1936. Reed, R. D.. and Hollister, J. S., Structural evolution of 

southern California, 157 pp., 9 pis.,,57 figs., Tulsa, Am. 

Assoc. Petroleum Geologists. (Also issued in Am. 

Assoc. Petroleum Geologists Bull., .vol. 20, pp. 1529- 

1704.) 

Palos Verdes Hills included in discussion of geology 

and structural history of Los Angeles Basin (pp. 112- 

135). 

1936. Schenck, H. G., Nuculid bivalves of the genus Acila: 

Geol. Soc. Am. Spec.'Paper 4, 149 pp., 18 pis., 15 figs. 

Includes records and illustrations of Acila castrensis 

from Pleistocene strata in San Pedro district. 

1936. Woodring, W. P., Bramlette, M. N., and Kleimpell, 

R,. M., Miocene stratigraphy and paleontology of Palos 

Verdes Hills, Calif.: Am. Assoc. Petroleum Geologists 

Bull., vol. 20, pp. 125-149, 3 figs. 

Preliminary account of stratigraphy and paleontology 

of Monterey shale in Palos Verdes Hills. 

1937. Howell, B. F., and Mason, J. F., Reef-forming serpulid 

from the Pleistocene of San Pedro, Calif.: Wagner 

Free Inst. Sci. Bull., vol. 12, No. 1, pp. 1-2, 2 figs. 

INTRODUCTION 

1937. 

1937. 

Description of "Serpula" saxistructoris, from the San 

Pedro sand of Deadman Island. Packard (Jour. 

Paleontology, vol. 16, p. 778, 1942) suggested that this 

is the Recent cirratulid Dodecaceria fistulicola and 

implied that the reported occurrence as a fossil needs 

confirmation. 

Reinhart, P. W., Three new species of the pelecypod 

family Arcidae from the Pliocene of California: Jour. 

Paleontology vol. 11, pp. 181-185, pi. 28. 

Area sisquocensis recorded from Hilltop quarry 

[Lomita marl]. 

1937. Thompson, W. O., Original structures of beaches, bars, 

and dunes: Geol. Soc. America Bull., vol.> 48, pp. 723- 

752, 8 pis., 6 figs. 

Cross-laminated sand in San Pedro sand at San Pedro 

interpreted as lower foreshore deposits superimposed 

on upper foreshore deposits (pp. 742-744). 

1937. Walker, E. F., Sequence of prehistoric material culture at 

Malaga Cove, Calif.: Masterkey, vol. 11, No. 6, pp. 

210-214, 2 figs. 

Stratigraphy and typology of four human culture 

levels, the lowest in uppermost 3 feet of alluvium 

[nonmarine cover on lowest terrace] and the others in 

overlying dune sand. 

Willett, George, Additions to knowledge of the fossil 

invertebrate fauna of California:. Southern California 

Acad. Sci. Bull., vol. 36, pp. 61-64, pis. 24-25. 

Comments on 19 species of mollusks, 2 of which are 

new, from lower part of strata exposed at Timms Point 

heretofore not recorded from that locality. 

1938. Natland, M. L., New species of Foraminifera from off the 

west coast of North America and from the later Tertiary 

of the Los Angeles Basin: California Univ. Scripps 

Inst. Oceanography Bull., tech. ser., vol. 4, No. 5, 

pp. 137-164, pis. 3-7; 

Two species (Virgulina seminuda and Cibicides 

spiralis) .recorded from Repetto siltstone at Lomita 

quarry. 

1938. Grant, U. S., IV, and Hertlein, L. G., The West American 

Cenozoic Echinoidea: Calif. Univ. at Los Angeles Pub. 

Math. Physical Sci., vol. 2, 225 pp., 30 pis., 17 figs. 


1938. Woodring, W. P., Lower Pliocene mollusks and echinoids 

from the Los Angeles Basin, California, and their inferred 

environment: U. S. Geoh Survey Prof. Paper 190, 

67 pp., 9 pis., 2 figs. 

Brief description of Repetto formation in Palos Ver 

des Hills (pp. 4-5) and records of Lima hamlini from 

that area (pp. 47-49). 

1938. Kleinpell, R. M., Miocene stratigraphy of California, 450 

pp., 22 pis., 14 figs., Tulsa, Am. Assoc. Petroleum 

Geologists. 

Includes correlation of Miocene strata in Palos Verdes 

Hills (see fig. 14), records of Foraminifera from those 

deposits, and illustrations of 23 species based on material 

from that area, 13 of which are new. 

1938. Lyon, G. M., Megalonyx milleri, a new Pleistocene ground 

sloth from southern California: San Diego Soc. Nat. 

History Trans., vol. 9, No. 6, pp. 15-30, pi. 1, figs. 1-7. 

Description of ground sloth remains, including skull, 

from nonmarine cover of lowest terrace at 'Second and 

1939. 

1939. 

Beacon Streets, San Pedro. 

Macdonald, G. A., An intrusive peperite at San Pedro Hill,. 

Calif.: .California Univ. Dept. Geol. Sci. Bull., vol. 24. 

pp. 329-338, 6 figs. 

Structural relations and petrography of basalt near 

Point Vicente. Intruded on sea floor under thin cover 

of contemporaneous sediments. 

Willett, G., A new species of mollusk from the San Pedrcc 

Pleistocene: Southern California Acad. Sci. Bull., voL 

38, pp. 202-203, pi. 54. 

Description of Alabina effiae from strata assigned" hit 

present report to Lomita marl. 

1940. Berry, S. S., New Mollusca from the Pleistocene of San< 

Pedro, Calif.; I: Bull. Am. Paleontology, vol. 25,. No.. 

94a, 18 pp., 2 pis. 

Description of 6 species from lower Pleistocene strata*, 

and one from upper Pleistocene strata. 

1941. Berry, S. S., New Mollusca from the Pleistocene of Sam 

Pedro, Calif.; II: Idem, vol. 27, No. 101, 18 pp_.2 1 pi. 

Description of 7 species and 1 subspecies from 

quarry [Lomita marl].

8 GEOLOGY AND PALEONTOLOGY OF PALOS VERDES HILLS, CALIFORNIA 

1941. Lyon> G. M., A Miocene sea lion from Lomita, Calif.: 

California Univ., Pub. Zoology, vol. 47, pp. 23-42, 

pis. 2-6, 2 figs. 

Description of sea lion remains, assigned to Pontolis 

magnus, from diatomite [Valmonte diatomite member 

of Monterey shale] at quarry of Dicalite Co. 

1941. Wissler, S'. G., Stratigraphic formations [relations] of the 

producing zones of the Los Angeles Basin oil fields: 

California Div. Mines Bull. 118, pt. 2, pp. 209-234, pi. 

5, figs. 88-94, 1 table. 

Includes discussion of Repetto siltstone at Malaga 

Cove (pp. 217-218) and of correlation of Miocene strata 

of Palos Verdes Hills with subsurface Miocene section 

of Los Angeles Basin (p. 222). 

1942. Miller, Loye, and De May, Ida, The fossil birds of Cali 

fornia: California Univ., Pub. Zoology, vol. 47, No. 4, 

pp. 47-142. 

Includes records and discussion of Miocene and 

Pleistocene birds from Palos Verdes Hills. 

1943. David, L. R., Miocene fishes of southern California: 

Geol. Soc. America Spec. Paper 43, 193 pp., 16 pis., 

39 figs. 

Includes description and discussion of 5 species of 

fish from the Altamira member of the Monterey shale 

at a locality near Whites Point (pp. 81-88). 

1943. LeRoy, L. W., Pleistocene and Pliocene Ostracoda of the 

costal region of southern California: Jour. Paleontology, 

vol. 17, pp. 354-373, pis. 58-62. 

.Includes descriptions of species from Lomita marl, 

Timms Point silt, and San Pedro sand. 

1943. Reinhart, P. W., Mesozoic and Cenozoic Arcidae from 

the Pacific slope of North America: Geol. Soc. Am. 

Spec. Paper 47, 117 pp., 15 pis., 3 figs. 

Includes records of Pleistocene species from San 

Pedro district. 

1944. Willett, George, Northwest American species of Gly- 

cimeris: Southern California Acad. Sci. Bull., vol. 42, 

pt. 3, pp. 107-114, pis. 11, 12, 1943 (1944). 

Specimens of Glycymeris profunda from Hilltop quarry 

are described and figured. 

1944. Campbell, A. S., and Clark, B. L., Miocene radiolarian 

faunas from southern California: ' Geol. Soc. Am., 

.; Special Paper 51, 76 pp., 7 pis. 

....., , Most of the Radiolaria described are from the 

Valmonte diatomite and Malaga mudstone of the 

Palos Verdes Hills. 

GEOGRAPHY 

, ,, ( , GEOGRAPHIC RELATIONS 

The Palos Verdes Hills constitute an isolated upland 

peninsula projecting into the .ocean at the southwest 

border of the Los Angeles Basin, which is a gently 

sloping- lowland extending seaward from Los Angeles. 

(See pi. 2.) In general features this peninsula resembles 

the islands off the coast of southern California; indeed 

during parts of Pleistocene time it was an island. 

'Northwest of the Palos Verdes Hills a belt of irregular 

dune-sand topography extends inland from the coast 

and overlaps the lowland and the northwestern border 

of the hills. 

Industrial, agricultural, and residential districts are 

located throughout the Los Angeles Basin. The oil 

industry holds an important position. Los Angeles 

Basin fields have produced almost half of California's 

oil. 14 In 1936-37 two new fields were discovered in the 

southern part of the basin, El Segundo and Wilmington. 

As shown in figure 1, the Wilmington field is in the 

harbor district close to the northeastern border of the 

Palos Verdes Hills. The Torrance field occupies, a 

large area on an ill-defined ridge extending eastward 

from the belt of dune sand near the coast. The El 

Segundo field is located farther north at the eastern 

edge of the dune-sand area. The 'Playa Del Rey field is 

W Tor a brief account of oil development in the Los Angeles Basin see Hoots, H. W. 

Oil development in the Los Angeles Basin: 16th Tnternat.Geol. Congress Guidebook 

15, pp. 26-30. pis. 6-8, 1932. 

at the seaward end of the wide, flat valley now occupied 

by Ballona Creek and extends southeastward into the 

area of dune sand. In stratigraphic succession and in 

general geologic history these 4 fields resemble the Palos 

Verdes Hills more closely than other fields in the Los An 

geles Pasin. They are also the most recently discovered 

fields in the basin, with the exception of the Torrance, 

a relatively old field, where, however, new activity 

has resulted from development of the other 3 fields. 

SURFACE FEATURES 

The Palos Verdes Hills represent a miniature Coast 

Range mountainous area of low altitude. They have a 

maximum northwest-southeast length of about 9}£ miles 

and a width of 4 to 5 miles. San Pedro Hill, the highest 

hill, has an altitude of 1,480 feet above-sea level. 

The crest and the greater part of the upper slopes of 

the hills form a rolling upland, characterized by smoothly 

rounded hills and wide, gently sloping valleys. The 

lower slopes are marked by a series of coastal terraces. 

Deep canyons advancing inland across the terraces are 

destroying the rolling upland. 

The west and south coasts are bordered by a sea cliff 

that has in general a height of 100 to 150 feet. At Long 

Point, on the south coast, the height of the cliff is 

exceptionally low, 50 feet, whereas at Bluff Cove and 

Malaga Cove, on the west coast, it is exceptionally high, 

300 and 200 feet, respectively. The sea cliff along the 

east coast in the city of San Pedro has a height of about 

50 feet. 

LAND USE 

Areas in the Palos Verdes Hills, like those in the 

Los Angeles Basin, are used for agricultural, residential, 

and industrial purposes. 

San Pedro has grown rapidly since the construction of 

a deep-water harbor in 1910-14. Shipyards, docks, 

warehouses, and establishments for handling fish are 

located along the water front and nearby. Sand and 

gravel pits and plants for treating the products from 

them are located along the north border of the hills. A 

diatomite quarry and plant are located in the same re 

gion, near the mouth of Agua Negra Canyon. These 

plants are the only industrial establishments at a con 

siderable distance from the water front, and they also 

represent the only industries utilizing the mineral 

resources of the hills. 

The residential district of San Pedro has spread from 

the flat coastal terrace along the water front westward 

to the lower slopes of the hills. The Palos Verdes land 

grant, comprising essentially the western two-thirds of 

the hills, is being held for residential and estate develop 

ment. Most of the development so far is in the Malaga 

Cove, Valmonte, Margate, and Miraleste districts, 

which are under the control of the Palos Verdes Estates, 

and in the Rolling Hills district. 

Most of the arable land outside the residential and 

estate districts, both within and outside the Palos 

Verdes grant, is now used for agricultural purposes. 

Agriculture as practiced in this region depends on a 

balance between factors involving topography, soil, and 

climate, which have been discussed recently by Raup. 16 

San Pedro has a mean annual precipitation of 10% 

inches, and Los Angeles, 20 miles inland, has 15 inches. 16 

" Raup, H. F., Land-use and water-supply problems in southern Californ ia; market 

gardens of the Palos Verdes Hills: Geog. Rev., vol. 26, pp. 264-269, 4 figs., 1936. 

10 Los Angeles (length of record 53 years) and San Pedro (length of record 20 years 

for precipitation and 11 years for temperature) data from Climatic Summary of the 

United States, section 18: U. .S. Weather Bur., pp. 2-3, 23, 28,1932. Point Vfcente 

data (length of record 11 years)-from Raup, H. F., op. cit.', p. 266.

GEOGRAPHY 

FIOUIIE 1. Sketch map of Los Angeles Basin and borders showing location of Palos Verdes Hills with reference to other geographic features. 

Hoots and Kew (16th Intcrnat. Geol. Gong. Guidebook 15, pi. 6, 1932). 

Crops are grown in the Palos Verdes Hills without 

irrigation, but farther inland the same crops need irriga 

tion for successful maturing, despite the greater rainfall. 

The .maturing of crops without irrigation in the Palos 

Verdes Hills is.controlled by higher relative humidity 

and more equable temperatures, owing to proximity of 

the ocean. Point Vicente on the south coast of the hills 

has a mean relative humidity of 71 percent; at Los 

Angeles the noon mean relative humidity is 51 percent. 17 

August, the warmest summer month, has a mean tem 

perature of 66.5° F. at Point Vicente, 67° at San Pedro, 

and 71° at Los Angeles. The high fogs that are preva 

lent in the morning along the coast during the spring 

and early summer are an important factor, as they 

reduce evaporation during the growing season of most 

of the crops. The soils under cultivation in the Palos 

Verdes Huls consist principally of clay loam and clay 

adobe, 18 Avhich retain moisture. The soil is plowed 

under proper moisture conditions soon after the first 

winter rains. In the vegetable-growing districts it is 

frequently cultivated to reduce evaporation. 

The soils of the lower part of the Monterey shale are 

generally brownish and contain numerous stones, com 

posed of hard cherty shale, .and larger pieces of lime 

stone. In cultivated areas the largest pieces of lime- 

» The time of day is not specified for the Point Vicentc records, but is presumably 

noon. At Los Angeles the mean relative humidity is 77 percent at 8 a. m., 51 percent 

at noon, and 01 percent at 8 p. m. 

'« Nelson, J. w., and others, Soil survey of the Los Angeles area, Calif.: U. S. Bur. 

Soils Field Operations Advance Sheets, 78 pp., 3 pis., map, 1919 (18th Ann. Kept., 

pp. 2347-2420, 3 pis., map. 1921). 

Adapted from 

stone are usually gathered and dumped on steep slopes 

between terrace treads or into ravines. (See pi. 24, D.) 

The soils of the upper part of the Monterey shale are 

darker, dark gray to black, and generally contain few 

stones. The residual basalt soils and the nonresidual 

terrace-cover soils are reddish brown, but the terrace- 

cover soil is more sandy than the basalt soil. 

The lower part of the southwest, south, and southeast 

slopes and small areas along the lower course of George F 

Canyon and on the north slope, east of the Palos Verdes 

golf course, are leased to tenants living on small tracts. 

Fresh vegetables, principally tomatoes and squash, but 

also beans, peas, cucumbers, and corn are. grown in 

these districts. The lower terrace treads are most ac 

cessible and most readily -tilled. Some rises that are 

not too steep and a few terrace treads and flats high on 

the south slope are under cultivation. The rolling up 

land along the crest and upper slopes and most of the 

north slope are leased to tenants living on large ranches. 

Lima beans, which are dried for the market, are grown 

on areas of gentle declivity along the western part of 

the crest and on adjoining parts of the north and south 

slopes, mostly on the dark soils of the upper part of the 

Monterey shale. Barley, generally used for hay, is 

grown on part of the rolling upland and on gentler de 

clivities of the north slope, and wild oats are cut for hay 

on some of the steeper slopes. 

Part of the northeast slope near San Pedro is used for 

dairy pasturing. Sheep are grazed during part of the


Middle'Miocene 

nniiN uiuiiiiiiiiiiiimnTmn 

Lower Miocene 

and Oligocene (?) 

.'.' Upper Cretaceous 

LOS ANGELES BASIN 

NORTH OF NEWPORT 

INGLEWOOD UPLIFT 

Vertical scale 

1000 0 1000 5000 Feet 

FIGURE 2. Generalized stratigraphic sections in western part of Los Angeles Basin and its borders. Santa Monica Mountains section after Hoots (U. S. Geol. Survey 

Prof. Paper 165-C); Los Angeles Basin sections compiled from various sources.

year on the north slope, and small areas along or near 

the crest are used for ranch pasturing. 

STRATIGRAPHY AND PALEONTOLOGY 

OUTLINE OF STRATIGRAPHY 

The stratigraphic section in the Palos Verdes Hills is 

greatly abbreviated and incomplete as compared with 

sections along the north border and in the northern part 

of the Los Angeles Basin. (See figs. 1, 2.) In the 

Santa Monica Mountains, which lie along the north 

west border of the basin, and also in the Santa Ana 

Mountains, at the southeast border, the oldest forma 

tion consists of argillite, phyllite, and slate intruded by 

granitic rocks. Triassic fossils have been found in the 

argillite of the Santa Ana Mountains, but in both moun 

tain areas the argillite and associated rocks may include 

deposits of Jurassic age. In both mountain areas these 

basement rocks are overlain by a thick succession of Up 

per Cretaceous and Tertiary formations. A similar sec 

tion underlies presumably the northern part of the Los 

Angeles Basin. Thousands of oil wells have penetrated 

the upper part of this section and have revealed a suc 

cession of Hcistocene and Pliocene formations that are 

much thicker than corresponding formations along the 

foot of the Santa Monica Mountains. Many wells in 

the northern part of the basin have also reached the 

upper Miocene. 

In the southern part of the basin, south of the 

Ncwport-Inglewood uplift, which extends from New 

port Beach to and beyond Inglewood, the basement 

consists of Franciscan (?) schist of doubtful Jurassic 

ago. Kesting on the schist are deposits of Miocene 

age, upper Miocene in most of the area and middle 

Miocono in the Palos Verdes Hills and at the seaward 

margin of the basin east of the hills; that is, the Upper 

Cretaceous, Paleocene, Eocene, Oligocene (?), and 

lower Miocene formations of the Santa Monica and 

Santa Ana Mountains, representing a thickness of 

12,000 feet in the Santa Monica Mountains, are 

missing. The Pliocene and Pleistocene formations in 

the southern part of the basin, are similar to those in 

the northern part but are considerably thinner, and 

in many areas parts of the Pliocene section are missing. 

The N'cwport-Inglewood uplift is thought by many 

geologists to mark a deep-seated fault. It has been 

suggested that if a deep-seated fault lies along the 

uplift, the fault probably represents .the boundary 

between the axeas of schist and granitic basement. 19 

The section exposed in the Palos Verdes Hills 

represented on a larger scale in figure 3, is essentially 

the same as the subsurface section south of the New- 

port-Inglewood uplift.- As in the subsurface section, 

Franciscan (?) schist forms the basement. The Plio 

cene section is, however, more condensed than the 

subsurface Pliocene, and parts of the subsurface Plio 

cene are not represented. The Miocene section is 

thicker than it is in the Playa del Rey, ElSegundo, and 

Torrance anticlinal areas north of the hills but is thinner 

than in the syncline between the El Segundo and Tor- 

ronco fields and in the Wilmington field an anticlinal 

area east of the hills. (See fig. 1.) The Miocene sec 

tion in the hills includes older strata than is found in 

any of the nearby subsurface area so far explored. On 

the north slope of the hills, however, the oldest strata 

i» Rood, R D., and Holllstcr, J. S., Structural evolution of Southern California. 

Am Assoc Petroleum Geologists Bull., vol. 20, pp.i'1678-1679, 1936: Am. Assoc: 

Petroleum Geologists, pp. 132-133, Tulsa, Okla.,i|l936. 

STRATIGRAPHY 11 

are of the same age as those resting on schist in the 

Wilmington field. 

The Miocene of the Palos Verdes Hills has an ex 

posed thickness of about 2,000 feet. Subsurface data 

indicate that the maximum thickness of the Miocene 

PLEISTOCENE 

Lov/er 1 1 Pliocene 

UPPER MIOCENE 

[ j 

MIOCENE MIDDLE 

IH 

0. 

Q. 

3 

j 

Monterey sh 

C 

1a 

deposi s 

Pedro San 

sand 

Jl« 

siltstone 

1 

E 

I 

§ 

Lomita mar 

member jne 

£ 

a 

s 

.0 

E 

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1 

I 

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1 i 

I 5 

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S 

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; ' ;' .' î'.'.is.'o;.'-': ' ' ' ' '. ; 

;.;.;.-.v.v_.;.;.-.;.;.;.;.;.;.-, .; 

; ::^;:^77-;'.:^?.^; : 

^-itP^v;-. /v;-;-:^: 

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f~r l~v|~7 IT"' f"1" ' ~*~ -'~ "'- 

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âj,^ ^- « _ô,___.2i 

§=^-a_=J&,=i^_r^S_g: 

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iiiiiiniiiiiiiiiiiiimiiiiiiiiHMiiiiiiiiiiiiiiiiii 

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i:ninnmiiiiiiiniii||iiiiiiiiigiiii!iiiiiiiiiiiiiiiini 

--- ~- 

iMimiiinuiiiniininiiiniiiiiiiiiuiiiiuiiiiiiin 

Subsurface data indicate about 

2,000 feet of unexposed 

Miocene strata 

Franc scan (?) 

schist 


100 0 300 Feet 

SPECIAL SYMBOLS 

Hard siliceous shale 

(mostly cherty shale i 

On north slope of hills 

strata at about'this horizon 

rest on schist basement 

3. Generalized stratigraphic section in Palos Verdes Hills. 

is at least 4,000 feet, but the schist surface is irregular. 

The exposed part of the Miocene section is assigned to 

the Monterey shale, which is subdivided into the fol 

lowing members in ascending order: Altamira shale 

member, Valmonte diatomite member, and Malaga

12 


mudstpne member. The .lower and middle parts of the 

Altamira member are assigned to the middle Miocene 

and the upper part and the Valmonte and Malaga 

members to the upper Miocene. Basalt, generally in 

the form of sills, is found in the lower and middle parts 

of the Altamira. 

The Monterey shale is overlain disconformably by the 

Repetto siltstone of lower Pliocene age. The maxi 

mum exposed thickness of the Repetto siltstone is 

about 150 feet, the top being marked by an uncom- 

formity. It represents a greatly condensed section of 

parts of the Repetto formation of the Los Angeles 

Basin, which has a thickness of 2,000 to 5,000 feet. 

The upper Pliocene, represented in the basin by a 

thickness of 2,000 to 3,000 feet of strata assigned to the 

Pico formation, is missing. 

Uncomformably overlying the Repetto siltstone and 

overlapping different parts of the Monterey shale are 

350 to 600 feet of deposits assigned to the lower Pleisto 

cene. In most' areas these strata consist chiefly of 

sand, designated the San Pedro sand. At places a 

calcareous facies, the Lomita marl, is at the base of the 

section. A silt facies, either at the base of the lower 

Pleistocene strata or between the Lomita and San 

Pedro is designated the Timms Point silt. These three 

formations are the thin marginal equivalent of an unde 

termined lower part of the Pleistocene of the Los 

Angeles Basin, which has a thickness of as much as 

2,000. feet. 

Marine deposits, generally a few feet thick, have 

been found on 9 of the 13 mam marine terraces, all of 

which are considered younger than the lower Pleisto 

cene strata and are assigned to the upper Pleistocene. 

The most extensive marine terrace deposits are those 

on the lowest terrace. They overlie unconformably 

the lower Pleistocene or older formations and are desig 

nated the Palos Verdes sand. Nonmarine deposits, 

constituting the nonmarine terrace cover, overlie the 

marine sediments on the terraces or rest directly on the 

terrace platform. They are considerably thicker than 

the marine deposits. The marine and nonmarine 

terrace deposits are the equivalent of an undeter 

mined upper part of the thick Pleistocene section in the 

basin. The nonmarine cover on the lowest terrace 

merges into the upper part of the older alluvium of 

the basin. 

JURASSIC (?) SYSTEM 

FRANCISCAN (?) SCHIST 

DISTRIBUTION AND IJLTHOLOGY 

Schists of doubtful Franciscan age are the oldest 

rocks that crop out in the Palos Verdes Hills. These 

rocks were noticed by Watts, 20 and some of the litho- 

logic types have been described by Woodford. 21 They 

were not examined carefully during the present investi 

gation, and their structure was not studied. 

The metamorphic rocks are exposed along a wide 

anticline modified by minor folds in George F Canyon 

and its tributaries and nearby. The upper surface of 

the schist, which forms the floor on which the Miocene 

strata rest, is evidently irregular, though it conforms 

in a general way to the folds in the Miocene rocks. 

The schistosity or foliation is generally at fairly low 

angles and is roughly parallel to the strike and dip 

ao Watts, W. L., Oil and gas yielding formations of California: California Min. 

Bur. Bull. 19, p. 54, 1901. 

ai Woodford, A. O., The Catalina metamorphic facies of the Franciscan series: 

California Univ., Dept. Geol. Sci., Bull., vol. 15, pp. 49-68, pis. 5-7, 2 figs., 1924. 

of the overlying Miocene strata, as observed by 

Woodford. 22 

The metamorphic rocks include a variety of schists. 

Green to greenish gray quartz-sericite schist, .red- 

weathering to lavender-weathering quartz-talc schist 

containing much hematite, and bluish schist consisting 

principally of quartz and glaucophane or crossite are 

the most common. Woodford 23 described quartz 

schist, quartz Talbite schist, and blue schist in which 

crossite is more abundant than glaucophane. 

A saussuritized basic igneous rock is associated with 

the schists. This rock was probably a diabase or 

gabbro, but augite is apparently the only unaltered 

original constituent. Lawsom'te is common in some 

of this altered rock, and much chlorite and glaucophane 

are developed along shear planes. iVt places the altered 

igneous rock is cut by quartz veins. 

A small area of quartz schist, exposed on the crest 

of an anticline in a canyon east of Palos Verdes Drive 

East, about three-quarters of a mile southeast of 

George F Canyon, represents an outcrop of schist or 

an exceptionally large boulder in the Miocene strata 

close to the schist contact. A little farther down the 

canyon, but apparently within the outcrop of Miocene 

sandstone, are two smaller poorly exposed masses of 

schist, one 5% by 4 feet and the other 4 by 2 feet, that 

may represent large boulders or small outcrops of 

schist. Such large boulders were not recognized, 

however, in the main schist area, where th e relations 

between Miocene rocks and schist are clearer, and these 

apparent masses may be a further indication of the 

irregular schist surface. 

Schist was penetrated in the Whites Point tunnel on 

the crest of an anticline that appears to be the south 

eastward extension of the anticline just mentioned. 

(See section E E', pi. 1.)" On the north limb of the 

anticline the schist is decomposed at the contact with 

the Miocene strata, forming a layer of green clay about 

a foot thick. Most of the schist in the core of the anti 

cline is altered. It contains plates of glaucophane 1 to 

2 inches in diameter arid minor amounts of talc and 

chloritic minerals. Near the contact with the Miocene 

strata on the south limb of the anticline the schistosity 

is vertical; 50 feet farther north it is nearly horizontal. 

On the crest of the anticline the rock is made up of frag 

ments of micaceous and schistose minerals that form a 

matrix in which are embedded angular to slightly 

rounded fragments of quartz. Toward the north this 

breccia is in contact with a nearly vertical ledge of schist 

that strikes at right angles to the tunnel line. The 

breccia may represent material that accumulated along 

a cliff, but slickensides suggest that the ledge of schist 

marks a fault and that the breccia is a fault breccia. 

The schist is cut by two systems'of joints. The joints 

of one system are virtually vertical and strike almost 

at right angles to the tunnel line; those of the other sys 

tem are approximately horizontal. In both systems the 

joints are spaced about 8 feet apart. 

Six wells drilled in the hills penetrated schist. The 

subsurface altitude of the schist in the Palos Verdes 

Hills is discussed under the heading "Oil possibilities," 

page 119. 

AGE 

The age of the schist is unknown other than that it is 

obviously pre-Miocene. The occurrence of glauco 

phane schist and altered basic igneous rocks suggests 

» Woodford, A. O., op. cit., p. 52. 

» Woodford, A. O., op. cit., pp. 54. 57. pi. 7.

correlation with the Franciscan of the Coast Ranges. 

The Franciscan, an extensive description of which has 

been published recently by Taliaferro, 24 consists chiefly, 

however, of arkosic sandstone, shale, radiolari.au chert, 

limestone, and volcanic rocks. Glaucophane schist 

and other metamorphic rocks are local and relatively 

rare rock types associated with intrusive igneous rocks. 

In view of these relations Woodford 25 designated the 

metamorphic rocks of the Palos Verdes Hills and the 

similar more extensive rocks of Santa Catalina Island 

as the Catalina metamorphic facies of the Franciscan. 

The absence of unaltered sedimentary rocks indicates 

that the mctamqrphics of the Palos Verdes Hills and 

Santa Catalina Island are older than the Franciscan, 

an alternative considered by Woodford. 26 This matter 

has been emphasized by Taliaferro, 27 who objected to 

including these metamorphics in the Franciscan. It 

may be advantageous to designate them as the Catalina 

schist. 

If the .metamorphics of the Palos Verdes Hills are 

older than Franciscan, they are Jurassic or older. On 

the basis of strat.igraph.ic relations in southern Oregon 

and less satisfactory evidence in the California Coast 

Ranges, Taliaferro 2S concluded that the age of the Fran 

ciscan can be restricted to narrow limits in the late 

Upper Jurassic Tithonian (used in the broad sense to 

include Port!andian) and possibly uppermost Kim- 

mcridgian. 

MIOCENE SERIES 

MONTEBEY SHALE 

GENERAL RELATIONS 

Strata of Miocene age rest directly on the Franciscan 

(?) schist. The Miocene deposits overlap the schist, 

basement .northward, the strata overlying the schist on 

the north, slope of the hills being younger than those on 

the south slope of the central part of the hills, where the 

base of the Miocene section is not exposed. 

The Miocene deposits include a variety of rocks, but 

hard silica-cemented shale and soft shale containing 

siliceous microfossils are the thickest and most con 

spicuous constituents. Early investigators of the 

geology of this region recognized that these unusual 

rocks are similar lithologically to those elsewhere in the 

Coast Ranges designated at that time the Miocene 

bituminous shale and later the Monterey shale. The 

>« Tnlinferro, N. L., Franciscan-Knoxvillo problem: Am. Assoc. Petroleum Geolo 

gists Bull., vol. 27, pp. 109-219, 7 pis., 7 figs., 1943. 

" Wood ford. A. 0., op. cit., p. 49. 

'» Woodford, A. 0., op. cit., p. 02. 

« Tnlinferro, N. L., op. cit., pp. 122-125. 

" Taliaferro, N. L., Geologic history and structure of the central Coast Ranges of 

California, in Jenkins, 0. P., and others, Geologic formations and economic develop 

ment of the oil and gas fields of California: California Div. Mines Bull. 118, pt: 2, pp. 

125-120,1941; Geologic history and correlation of the Jurassic of Southwestern Oregon 

and California: Gool. Soc. America Bull., vol. 53, pp. 85-87, 1942; Franciscan-Knox- 

villo problem: Am. Assoc. Petroleum Geologists Bull., vol. 27, pp. 190-195,1943. 

MIOCENE SERIES 13 

stratigraphic nomenclature of the Miocene section in 

coastal southern California became confused, however, 

at a later date by the introduction of two local forma 

tion names for Miocene strata including shale of Mon 

terey type Modelo formation proposed for strata in 

the Santa Clara Valley in the Ventura Basin northwest 

of the Palos Verdes Hills, and Puente formation pro 

posed for strata in the Puente Hills on the north border 

of the Los Angeles Basin northeast of the Palos Verdes 

Hills and by the raising of Monterey to group rank 

to include the underlying Vaqueros sandstone. The 

Miocene strata in the Palos Verdes Hills have been 

assigned generally to the Modelo formation and the 

corresponding Miocene subsurface section in the ad 

joining Los Angeles Basin to the Puente formation. It 

has been proposed recently to restore the name "Mon 

terey shale" as a formation name for Coast Range 

Miocene strata including shale of Monterey , type 

regardless of varying stratigraphic position within the 

Miocene. 29 According to this proposal, the Miocene 

strata in the Palos Verdes Hills are assigned to the 

Monterey shale. 

The Monterey shale of the Palos Verdes Hills is of 

middle to upper Miocene age. It has a maximum ex 

posed thickness of about 2,000 feet. The underlying 

schist does not crop out, however, in the area where 

the oldest strata are found. Outcrop data show a 

southward increase in thickness through the addition of 

older strata at the base of the section. Subsurface data 

in the Point Fermin and Long Point areas indicate 

that the maximum thickness of the Miocene is at least 

4,000 feet. 

LITHOLOGY 

Details of the stratigraphy and lithology of the 

Monterey ( shale were not determined in many areas, 

owing to meager exposures, to the apparent absence of 

distinctive lithologic units throughput hundreds of feet 

of strata, to minor structural complications that prevent 

determination of stratigraphic position on a basis of 

regional structure, and to changes in thickness and 

facies. The main features of the stratigraphic and 

lithologic succession seem to be well defined in some 

areas, but in other areas recognition of the main units 

is difficult, owing to lateral variations. On the basis 

of the succession in areas where the relations are fairly 

certain, the Monterey shale of the Palos Verdes Hills 

is divided into three named and mapped members, the 

principal features of which are summarized in the follow 

ing table: 

28 Woodring, W. P., Stewart, Ralph, and Richards, R. W., Geology of the Kettle- 

man Hills oil field, Calif.; stratigraphy, paleontology, and structure: TJ. S. Geol. 

Survey Prof. Paper 195, pp. 122-123,1940 [1941]. (The history of the name "Monterey" 

and the arguments involved in the proposal to use Monterey shale as a formation 

name are discussed in this publication.) Woodring, W. P., Bramlette, M. N., and 

Kleinpell, R. M., Miocene stratigraphy and paleontology of Palos Verdes Hills, Calif. 

Am. Assoc. Peteroleum Geologists Bull., vol. 20, No. 2, pp. 127,131,1936.


Subdivision 

Malaga mudstonemember... 

Valmonte diatomite member. 

Altamira shale member: 

Upper part...------- 

Middle part- 

Lower part. 

1 See footnote, p. 39. 

Thick 

ness (feet) 

300-600 

300-500 

100-300 

400-675 

276+ 

Subdivisions and principal features of Monterey shale in Palos Verdes Hills 

Principal lithologic constituents 

Radiolarian mudstone. 

Diatomite, diatomaceous shale, 

diatomaceous mudstone. 

Phosphatic shale, bituminous 

shale. 

Cherty shale, porcelaneous shale, 

chert, limestone. 

Silty,shale, sandy shale- 

Bramlette's terminology 30 for the siliceous rocks of 

the' Monterey is adopted in the present report. The 

terms used are defined briefly as follows: 

Chert: Hard massive dense vitreous rock composed prin 

cipally of silica. 

Laminated chert: Laminated but nonplaty rock similar to 

the chert mentioned above. 

Cherty shale: Hard platy dense vitreous rock composed prin 

cipally of silica. The most common type in the Palos Verdes 

Hills. 

Porcelaneous mudstone: Hard massive nonlustrous rock 

composed of silica and fine-grained elastics. 

Porcelaneous shale: Hard laminated platy nonlustrous rock 

composed of silica and fine-grained elastics. 

Diatomite: Soft massive or laminated rock containing abun 

dant diatoms. 

Diatomaceous mudstone: Soft massive rock composed of 

fine-grained clastic material containing diatoms. 

Diatomaceous shale: Soft layered or laminated rock com 

posed of fine-grained clastic material containing diatoms. 

Radiolarian mudstone: Soft massive rock composed of fine 

grained clastic material in which Radiolaria are more conspicuous 

than diatoms. 

Diatomite, diatomaceous mudstone, and diatoma 

ceous shale are loosely defined field terms. There are, 

of course, gradations between the three types. The 

term "diatomite" is used for rock at least 50 percent 

of which consists of diatoms. 

Rhythmically bedded shale refers to alternations of 

different rock types in units several feet or several 

inches thick. A finer lamination consisting of alterna 

tions of the same types is superimposed generally on 

the coarser units. Rhythmic bedding is characteristic 

of the fine-grained Monterey rocks, the term being 

used in the descriptive matter only for striking ex 

amples. The term "phosphatic shale" is used for 

shale containing layers and nodules of phosphatic 

material, probably impure cellophane. The phos 

phatic shale in the upper, part of the Altamira member 

and in the Valmonte member is soft. Phosphatic 

shale or siltstone in the middle part of the Altamira is 

generally hard and siliceous or calcareous. The term 

"bituminous shale" is used for tough, brown shale rich 

in organic matter. 

The three divisions of the Altamira member include 

coarse-grained clastic rocks sandstone, conglomerate, 

and breccia which are locally thick. Such material 

was not observed in the other two members of the 

Monterey shale. . Many of the sandstones contain a 

'° Bramlette, M. N., The Monterey formation of California and the origin of its 

siliceous rocks: U. S. Geol. Survey Prof. Paper (in preparation). 

Minor lithologic constituents 

Diatomite, diatomaceous shale, siltstone, lime- 

stone, volcanic ash. 

Mudstone, phosphatic shale, limestone, black 

chert, cherty shale, volcanic ash. 

Cherty shale, porcolaneous shale, silty shale, 

limestone, diatomaceous silt, diatomaceous 

shale, sandstone (locally thick), local brec- 

ciated shale, bentonitic tuff, volcanic ash, 

Silty shale, siltstone, diatomite, diatomaceous 

shale, phosphatic shale, sandstone, conglo 

merate, bentonitic tuff, pumice tuff (Mira 

leste tuff bed). 

Cherty shale, porcelaneous shale, limestone, 

sandstone, bentonitic tuff (including Portu 

guese tuff bed), local breccia composed of 

schist debris. 

Fossils 

Foraniinifera of Bolivina oWii/wazonc 1 . Radio- 

laria, diatoms, and other siliceous micro- 

fossils. 

Foraminifera of Bolivina hughesi zone, including 

Bolivina. decurtata and Bolivina goudkoffi sub 

zones. Diatoms and other siliceous micro- 

fossils. Hyalopecten &B.H. pecktiami. 

Foraminifera of Bolicina modeloensis and Buli- 

mina unigerinaformis zones. Diatoms and 

other siliceous microfossils. 

Foraminifera of Siphogenerina reedi, Siphogene- 

rina nuciformis. and Siphogenerina collomi 

zones. Fish scales. 'Diatoms and other sili 

ceous microfossils generally rare. Turrilelta 

ocoyana and other mollusks locally in sand 

stone. 

Foraminifera of Siphogenerina branneri zone. 

Fish scales. Diatoms generally only in lime- 

. stone concretions. 

notable quantity of blue soda amphibole derived from 

blue schist containing glaucophane or other soda am- 

phiboles. Blue-schist sandstone is a convenient term 

for such sandstone. 

Limestone, presumably more or less dolomitic, occurs 

throughout the Monterey but is much more abundant 

in the Altamira member than in the others. In many 

Altamira areas the only natural outcrops are ledges of 

limestone, and the ground is strewn with pieces of 

limestone. The limestone occurs as lenses, ranging in 

thickness from a few inches to several feet, and as con 

cretions. In the Altamira member the thickest lime 

stone beds are massive; the thinner beds are massive 

or laminated, and some of the laminated limestone is 

siliceous. In the Valmonte and Malaga members con 

cretions are more abundant than lenses. Concretions 

in laminated rock are laminated or massive. The Alta 

mira member contains also thin beds made up largely 

of dolomite grains having the texture of coarse-grained 

sand. 

Volcanic material is likewise common throughout 

the Monterey. It occurs generally as distinct beds 

containing virtually no other material. In the Alta 

mira shale the beds of volcanic material consis-t of more 

or less bentonitic tuff and pumiceous tuff, with the 

local exception of vitric ash near the top of the member, 

whereas in the Valmonte and Malaga members they 

consist of vitric ash. Owing to their stratigraphic 

importance two beds of tuff are named: the Portu 

guese tuff, a thick bentonitic tuff at the top of the 

lower part of the Altamira and the Miraleste tuff, a 

thin pumiceous tuff in the middle part of the Altamira. 

As in many other areas, the lower part of the Mon 

terey shale is characterized by hard silica-cemented 

shale, much of which contains molds of diatoms, and the 

upper part by softer rocks containing abundant pre 

served diatoms. This distinction affords the most ob 

vious basis for a lithologic subdivision and might be 

expected to prove useful in mapping. That this litho 

logic change does not take place even approximately 

at the same horizon in different areas in the Palos 

Verdes Hills is indicated by tracing the Miraleste tuff, 

as well as by other lithologic data and the foraminiferal 

faunas. Despite the varying stratigraphic position of 

the lithologic change, it would ordinarily be regarded 

as a satisfactory basis for the recognition and mapping 

of members. Such procedure is beset with special 

difficulties, however, in the Palos Verdes Hills, owing

LITHOLOGIC UNIT 

MIOCENE SERIES ' 15 

Malaga mudstone member' Bolivina obliqita zone 

Valmonte diatomite member Bolivina hughesi zone 

Upper part 

Middle part 

Bolivina goudkoffi 

subzone 

Bolivina decurtata 

subzone 

Bulimina uvigerinaformis zone 

_ 7 

Bolivina modeloensis zone 

Siphogenerina collomiand Siphogenerina 

wudformis zones 

(stratigraphic relations to each other and ioSiphogcn- 

erina reedi zone undetermined in Palos Verdes Hills) 

Siphogenerina reedi zone 

Lower part Siphogenerina branneri zone 

100 


100 

FIGURE 4. Chart showing relation between lithologic units and foraminiferal zones in Monterey shale of Palos Verdes Hills.


to intricate minor structural features in areas of the 

most extensive interfingering of these two main rock 

types. In. view of these relations an attempt to sub 

divide and map the formation on the basis of this, 

lithologic change was abandoned. 

In the western" half of the hills and on the south 

slope the change from hard cherty shale to softer dia- 

tomaceous rocks takes place approximately at the top 

of the phosphatic upper part of the Altamira member. 

The change in that area forms the basis for recognition 

and designation of the overlying Valmonte diatomite 

member. In the northeastern and eastern parts of the 

hills the change takes place at varying horizons in the 

middle part of the Altamira member. In those areas 

the Valmonte member was differentiated by the ocur- 

rence of relatively pure diatomaceous rocks, the dia 

tomaceous strata in the Altamira member including 

phosphatic shale, and blue-schist sand and silt. 

The Malaga mudstone member is characterized by 

the prevalence of massive mudstone. That member 

includes, however, diatomaceous shale, and the Val 

monte includes mudstone of the massive type. At 

Malaga Cove, where these members are well exposed, 

they are well differentiated. Owing to meager expo 

sures it is not known whether the distinction is as well 

denned in other areas. It is not known also whether 

the change from diatomaceous shale to massive mud- 

stone takes place at the same horizon from place to 

place. 

FOSSILS 

Foraminifera were found in the three members of 

the Monterey, and the age assignments are based on 

them. The material collected was identified by R. M. 

Kleinpell,' and the zonal assignments were made by 

him. A discussion of the foraminiferal zones of the 

California Miocene recognized by Kleinpell may be 

found in his publication. 31 The stratigraphic position 

of some collections of Foraminifera from the Palos 

Verdes Hills, particularly in the middle part of the 

Altamira member, was not determined, owing to in 

sufficient field data. The relation between lithologic 

units and foraminiferal, zones, according to present 

interpretations, is shown in figure 4. 

Diatoms are more abundant than Foraminifera in 

the Monterey, especially in the Malaga and Valmonte 

members and in the diatomite and diatomaceous shale 

in the middle and upper parts of the Altamira member. 

They were observed also in limestones and limestone 

concretions in the lower part of the Altamira. The 

extensive collections made during the field work have 

not, however, been examined. Other siliceous micro- 

fossils Eadiolaria, silicoflagellates, and sponge 

spicules occur with the diatoms and in some beds 

are more abundant than diatoms. Radiolaria from 

the Valmonte and Malaga members have been described 

recently by Campbell and Clark. 32 

Mollusks are rare in the Monterey, and none were 

observed in most of the fine-grained rocks. At a few 

localities shallow-water forms were found in sandstone 

in the middle part of the Altamira shale. The deep- 

water scallop Delectopecten occurs in the Valmonte 

diatomite but appears to be rare. 

Fish scales are the most abundant fossils, or the 

only ones observed, in much of the hard silica-cemented 

shale. In some areas they may be found in almost 

" Kleinpell, R. M., Miocene stratigraphy of California, pp. 103-135, Am. Assoc- 

Petroleum Geologists, Tulsa, Okla., 1938. 

sa Campbell, A. S., and Clark, B. L., Miocene radiolarian faunas from southern 

California: Qeol. Soc. Am., Special Paper 51, 76pp., 7 pis., 1944. 

any hand specimen. Fish skeletal remains are not 

abundant, though local collectors have found some 

well-preserved specimens in both hard cherty shale and 

soft diatomite. At numerous localities fragmentary 

cetacean remains, or fragmentary large bones that are 

presumably cetacean remains, were observed in hard 

limestone in the middle part of the Altamira member. 

Those observed include a fragmentary skull suggestive 

of a whalebone whale, and local collectors have found 

fragmentary skulls and jaws of toothed whales or 

dolphins. A small cetacean has been recorded from 

the Valmonte diatomite, and three sea birds from that 

member have been described. 

ALTAMIRA SHALE MEMBER 

The oldest member of the Monterey is designated the 

Altamira shale member. 33 The type region is on the 

south slope of the hills adjoining Altamira Canyon (see 

pi. 4). The Altamira is thicker than the overlying 

members and covers a much larger area. In the type 

region it has an exposed thickness of about 1,000' feet. 

On the north slope of the hills the thickness decreases to 

about 600 feet, owing to overlap on the schist basement. 

As shown in the table on page 14, the Altamira is 

divided into lower, middle, and upper parts character 

ized, respectively, by the prevalence of silty and sandy 

shale, cherty shale, and phosphatic shale. Each of these 

subdivisions, however, includes other rock types, and 

locally other rock types are prevalent; consequently in 

some areas differentiation of the three parts is not well 

defined, and no attempt was made to map them. Each 

part of the Altamira member has a coarse-grained 

detrital facies. The lower part includes a breccia com 

posed of schist debris. Sandstone and conglomerate are 

included in the middle part in the area where that 

division rests on the schist basement and elsewhere. At 

Point Fermin the upper part includes thick beds of 

coarse-grained blue-schist sandstone. 

Basalt, generally in the form of sills, is not known to 

penetrate strata above the middle part of the Altamira. 

In areas where basalt is present its distribution, there 

fore, shows roughly the distribution of the lower and 

middle parts of the Altamira. In extensive areas on the 

north slope of the hills, however, basalt is absent in 

the middle part." 

Sections of the Altamira in different parts of the hills 

are shown on plate 3. The most complete sections are 

exposed in canyons in the type region inland from 

Portuguese Point and Inspiration Point. A section 

including most of the middle part and all of the upper 

part is exposed in the sea^chS extending from Bluff Cove 

to Lunada Bay, but in that area the base of the middle 

part is not certainly identified, and the structure is 

complicated by minor folds. 

LOWER PART, INCLUDING PORTUGUESE TUFF BED 

The lower part of the Altamira shale .member is 

exposed in the Portuguese Canyon area and nearby on 

the south slope of the central part of the hills, where it 

has an exposed thickness of at least 280 feet. Strata in 

the Miraleste arid Bluff Cove areas appear to represent 

the lower part of the Altamira. 

In the Portuguese Canyon area the lower part of the 

Altamira consists chiefly of silty shale and sandy shale. 

Highly siliceous rocks are less abundant than in the 

middle part and consist mostly of silty porcelaneous 

33 Woodring, W. P., Bramlette, M. N., and Kleinpell, R. M., op. cit. (Am. Assoc. 

Petroleum Geologists Bull., vol. 20), p. 131,1936.

shale and porcelaneous mudstone rather than cherty 

shale; that is, most of it is less siliceous than that in the 

middle division of the member. A thick bentonitic tuff 

is chosen as the top of the lower part of the Altamira. 

This tuff is designated the Portuguese tuff bed, a name 

derived from Portuguese Bend. The type region is 

along Klondike Canyon, near Portuguese Bend. In the 

preliminary paper 3* Portuguese Canyon was errone 

ously cited as the type locality. Owing to inadequate 

exposures and the tendency of the tuff to slump and 

slide, the tuff was not continuously traced, except in 

small areas. The strata immediately below and above 

the Portuguese tuff show no sharp lithologic change. 

Silty shale and sandy shale are, however, more abundant 

below that bed, and cherty shale is more abundant 

above it. 

In the Bluff Cove area strata assigned to the lower 

part of the Altamira consist of silty sandstone, sandy 

siltstone, and a schist-debris breccia facies not found in 

any other area in the hills. 

STRATIGRAPHY AND LITHOLOGY 

PORTUGUESE CANYON AREA 

The lower part of the Altamira shale crops out in 

the area adjoining the extensive landslide inland from 

Portuguese Point and Inspiration Point. The best 

exposures were found in Portuguese Canyon and the 

unnamed canyon between Portuguese and Klondike 

canyons. Silty shale and sandy shale are the pre1 

vailing rocks in that area. Porcelaneous silty shale, 

porcelaneous mudstone and siltstone, altered tuf- 

iaceous material, limestone, and sandstone are the 

principal minor-constituents. Hard cherty shale and 

sandstone are less abundant than in the middle part of 

the Altamira. 

The following section (column 5, pi. 3) was measured 

in the unnamed canyon a quarter of a mile east of 

Portuguese Canyon: 

Section of lower part of Altamira shale member of Monterey shale 

in unnamed canyon a quarter of a mile east of Portuguese 

Canyon 

Ft. in. 

46. Thin-bedded sijlty shale; upper part not exposed. 5+ 0 

45. Sandy tuff.__._.______._.____......... 8 

44. Thin-bedded silty shale.______________________ 1 8 

43. Sandy limestone containing blue-schist shreds._. 8 

42. Thin-bedded silty shale --____--__----__-_-___ 6 

41. Lenticular laminated limestone._____________ 1 2 

40. Silty shale________________________________ 4 

39. Rusty fine-grained altered tuff (?).-----_-_-.__ 2 

38. Poorly exposed thin-bedded silty shale.________ 10± 0 

37. Rhythmically bedded silty shale; units of sandy 

shale at base and shale at top, each about 2 

inches thick._____________________________ 2 0 

36. Thin-bedded silty shale including, some sandy 

lenses__-__-____-______---__--____-___._ 8 8 

35. Impure altered tuff__________-______!________ . 6 

34. Hard brown imidstone containing altered pumi- 

coous fragments and small glass shards; limy 

concretions about a foot thick in basal part.._ 4 4 

33. Poorly exposed thin-bedded silty shale.__'______ 7 8 

32. Thin-bedded silty shale and fine-grained sandy 

shale________________________________ 10 10 

31. Altered tuff containing a few poorly preserved 

Foraminifera________________________-._.._ 1 8 

30. Hard porcelaneous mudstone and siltstone con 

taining a few molds of Foraminifera; some , x 

layers tuffaceous.-_________l_-_--_-_______ 3 2 

29. Coarse-grained sandy tuff, finer-grained at top; 

contains "bentonitifeed" glass shards that have 

a maximum length of a quarter of an inch or 

more.___________________________________ 2 6 

" Woodring, W. P., Bramlette, M. N., and-Kleinpell, R. M., op cit., p. 132. 



in unnamed canyon a quarter of a mile east of Portuguese 

Canyon Continued 

Ft. in. 

28. Hard porcelaneous mudstone.________________ 10 

27. Thin-bedded silty and sandy shale___________ 2 0 

26. Altered tuff.______.________________ » 6 

25. Hard thin-bedded porcelaneous silty shale; a , 

zone of diatom-bearing calcareous concretions 

2}£ feet above base._______________________ 7 8 

24. Thin-bedded silty shale-.._-._._____.__ 6 0 

23. Altered sandy tuff; upper 2 inches fine-grained-_ 6 

22. Silty shale and mudstone_____________________ 5 ' 7 

21. Altered sandy tuff-__-_--_-------._-_____-_- 10 

20. Limestone______________-_____-_-___________ 1 

19. Unexposed-_____-__-:__--____-----_-_-_--._ 12± 0 

18. Limestone____._____________-_---____-__-_ 9 

17. Thin-bedded silty shale_--_-_-_-_----_------_ 5 0 

16. Hard limjr siltstone____________-_-_-_--____-_ 1 0 

15. Thin-bedded silty shale.____.---_---_-_-_-_-_ 1 9 

14. Lenticular limestone.._______-_______._-_---_ 8 

13. Hard silty porcelaneous shale.___-_____.___--_ 6 8 

12. Lenticular limestone.________________________ 1 0 

11. Thin-bedded silty shale and clay; lower half hard 

and porcelarieous-__-__-_-__-_--_-_--_----_ 7 0 

10. Limestone_______--_--_--------------------- 1 H 

9. Rhythmically bedded silty and porcelaneous 

shale; units of more silty and more porcelane 

ous shale, each having an average thickne'ss 

of 1 to 2 inches---------...--------------- 7 2 

8. Impure sandy altered tuff._____-___-_-___.____ 2 ± 0 

7. Unexposed._-___--___---_-__--_-----------_ 6± 0 

6. Hard black baked limestone.___-_-_----__-_-_ 1 0 

5. Basaltsill... ....-. '-. ---- ---- . . 5 6 

4. Baked siliceous limestone. _________________ 9 

3. Thin-bedded silty and porcelaneous shale; not 

so hard nor so siliceous as unit 9____-_______ 7 4 

2. Limestone____________-_-------------------- 1 3 

1. Thin-bedded silty shale. ___________________ 2 0 

Basalt in core of pitching anticline. 

Approximate thickness of section, excluding 

unit 46___--..--_--_-__--_-----------_ 152 0 

The following section (column 4, pi. 3), measured in 

Portuguese Canyon, is an upward continuation of the 

preceding section. Unit 46 was matched in the two 

sections by a -comparison of lithology, with special 

reference to the tuffs and the thickness. 


in Portuguese canyon 

[Upward continuation of preceding section] 

Ft. in. 

56. Portuguese tuff bed, poorly exposed, thickness 

approximate-_____-_-_____-_-____--------- 40± 0 

55. Poorly exposed tuffaceous, sandy, silty, and 

porcelaneous shale; thickness estimated ______ 25 ± 0 

54. Poorly exposed silty shale.___________________ 9± 0 

53. Thin-bedded sandstone; top not exposed.------ 5± 0 

52. Massive sandstone..______-__-_------------- 8 6 

51. Hard sandy limestone or calcareous sandstone. __ 1 10 

50. Massive fine-grained to medium-grained sandstone 

containing blue-schist shreds.__-_-___- 7 0 

49. Rhythmically bedded thin-bedded fine-grained 

sandstone at base and silty sandstone at top, 

each about 2 itnches thick. _________________ 4 0 

48. Poorly exposed thin-bedded silty shale and sandy 

shale, the latter containing blue-schist shreds. 10 ± 0 

47. Yellow altered tuff-__--__----_-_-__-----_-__ 6 

46. Thin-bedded silty shale. Foraminifera of Siphogenerina 

branneri zone (locality 1) 3& collected 

from a limy bed lower in section corresponding 

to unit 34 of preceding section._____________ 14 «(** 0 

Approximate thickness of this section. ___._ 125 

Approximate thickness of section in canyon 

a quarter of a mile east of Portuguese 

Canyon......._______________________ 152 

0 

277 0 

M The fossil localities arc plotted on thc'gcologic maps (pis. 1, 14, 21) and are de 

scribed on pp. 120-125.

18 

Foraminifera, generally represented by poorly pre 

served material or molds, were observed at different 

horizons in this area. The best material, assigned to 

the Siphogenerina branneri zone, was collected at local 

ity 1 in Portuguese Canyon, as noted in the preceding 

section. 

The Portuguese tuff bed consists of light-colored 

bentonitic tuff. As shown in the view on plate 6, A, it 

is well exposed in the type region, where it has a thick 

ness of 55 feet. At the landward end of Inspiration 

Point the tuff is abruptly upturned on the south limb of 

an anticline" (see pi. 5) and is about 60 feet thick. On 

the west side of Abalone Cove tuffaceous material is ex 

posed through a thickness of 30 feet, and the debris, 

indicates that it continues upward through an additional 

thickness of about 30 feet. The scattered outcrops of 

the Portuguese tuff that were recognized are shown on 

the geologic map (pi. 1). In addition to these outcrops, 

tuff debris, doubtless. derived from this bed, was found 

at many localities along the north margin of the exten 

sive landslide in the Portuguese Canyon district and in 

stream cuts within the landslide area. Inasmuch as the 

strata, including the tuff, dip toward the landslide along 

NE. 

relatively soft porcelaneous shale. Foraminifera from 

silty shale (locality 2) are assigned to the same faunal 

zone as that in the lower part of the Altamira in the 

Portuguese Canyon area. 

BLUFF COVE AREA 

Strata exposed in the sea cliff at Bluff Cove, at the 

west end of the eastward-plunging Bluff Cove anticline, 

appear to represent the lower part of the Altamira shale 

but are lithologically different from those already de 

scribed. The Portuguese tuff was not recognized in 

this region. 

A sketch of the sea cliff at Bluff Cove is shown in 

figure 5. The statigraphic relations of some of the 

lithologic units are uncertain, owing to extensive slides 

and talus and to incomplete knowledge of the structural 

features. The schist-debris breccia forming the high 

greenish cliff appears to represent the oldest strata. 

Bedding is not clearly discernible in the breccia, but 

there is a vague suggestion of anticlinal arching toward 

the top of the cliff. The breccia consists of a rude mass 

of schist slabs embedded in an unsorted greenish muddy 

matrix (pi. 6, B). The schist slabs have a maximum 

FIGURE 5. Sea cliff at Bluff Cove, a, Pleistocene terrace deposits; 6, basalt in middle part of Altamira member of Monterey shnle; c, silty shale and cherty shale in middle 

part of Altamira shale; d, sandstone and conglomerate assigned to middle part of Altamira shale; e, silty sandstone and sandy siltstone in lower part of Altamira shale; 

/, schist-debris breccia assigned to lower part of Altamira shale. 

its east, north, and northwest margins, this bentonitic 

tuff probably acted as a lubricant for a mass of rocks 

that slid down dip into a structural basin and moving 

seaward overrode the lower marine terraces. 

The lower part of the Altamira shale probably crops 

out in other areas along anticlines on the lower part of 

the south slope of the Palos Verdes Hills east and west 

of the Portuguese Canyon area. The stratigraphic re 

lations in those areas are doubtful, however, as expo 

sures are generally poor and the Portuguese tuff was not 

certainly, recognized. Tuff debris, possibly derived 

from the Portuguese tuff, was found at several localities 

near the small landslide northwest of the extensive land 

slide just described. Some of the inadequately exposed 

rocks along the anticline in the deep canyon west of 

this small landslide probably represent the lower part of 

the Altamira. 

MIRALESTE AREA 

The lower part of the strata underlying the basalt 

sill on the Miraleste anticline is assigned to the lower 

part of the Altamira shale. A poorly exposed benton 

itic tuff on the south limb of the anticline, about 100 

feet stratigraphically below the base of the sill, is 25 or 

30 feet thick and may represent the Portuguese tuff. 

The strata underlying the tuff, as exposed in isolated 

areas, consist of silty shale, thin-bedded sandstone, and 

observed length of 3 feet, but most of them are less than 

half a foot long. Greenish schist is the most abundant 

rock, pieces of vein quartz are numerous, and blue 

schist is a minor but conspicuous constituent. Breccia 

of this type was not found elsewhere in the Palos Verdes 

Hills. It resembles the San Onofre breccia described 

by Woodford, 36 in the San Jpaquin Hills, 30 miles south 

east of the Palos Verdes Hills, and farther south along 

the coast. Like the San Onofre breccia the breccia at 

Bluff Cove may represent alluvial fan material deposited 

"at the foot'of a schist highland, or landslides and ava 

lanches derived from such a highland. At all events it 

is composed of rocks similar to those in the Franciscan 

(?) area in the Palos Verdes Hills. 

Thin-bedded, generally fine-grained silty sandstone 

and sandy siltstone form the lower part of the cliff 

north of the breccia. These strata are presumably 

younger. than the breccia and evidently are faulted 

against the breccia. A coarse-grained sandstone in 

these thin-bedded rocks contains much angular schist 

debris. Some layers of silty sandstone contain logs of 

carbonized and silicified wood as much as \% feet in 

diameter. Foraminifera from sandy siltstone (locality 

2a), found by Dr. Hampton Smith, are interpreted as 

representing the same faunal zone as that in the lower 

^ Woodford, A. O., The San Onofre breccia: California Univ.. Dept. Qeol. Sci. 

Bull., vol. 15, pp. 182-205, 1925. '

GEOLOGICAL SURVEY PROFESSIONAL PAPER 207 PLATE 2 

:^^5g^l 

'a I o s Ve rd e s H iTis ' ' vftMsds MJj^> 

\ 

_j?;m 

^f&-^s 

RELIEF MAP OF CALIFORNIA SHOWING LOCATION OF PALOS VERDES HILLS.


NW. 

WEST COAST SOUTHWEST OF 

MOUTH OF MALAGA CANYON 

Hard siliceous shale 

(mostly cherty shale) 

Fossil locality 10 

(Foraminifera suggestive of 

Siphogcnerina nuciformis zone) 

TRIBUTARY OF MIDDLE FORK 

OF ALTAMIRA CANYON 

V 4 > V?' J^V 44> 

Fossil locality 3a 

(Poorly preserved Foraminifera 

of uncertain zonal position 

in Kleinpall's Luisian stage) 

1 Scattered exposures on hillside 

PORTUGUESE CANYON 

^*4***


^ HnMMHMHMHBMHMHMMHMBK^: 

^ppl^P|^^M| 

IIP 

VIEW ON SOUTH SLOPE OF PALOS VERDES HILLS LOOKING NORTHWARD UP ALTAMIRA CANYON AND TRIBUTARIES. 

PROFESSIONAL PAPER 207 PLATE 4 

Gently dipping strata in background consist of Altamira member of Monterey shale overlain by thin cover of Valmonte diatomite member. Skyline shows rolling upland. 

Foreground and middle distance are part of landslide. Photograph by Palos Verdes Estates. 

-ff , "'


VIEW ON SOUTH COAST OF PALOS VERDES HILLS LOOKING WESTWARD ACROSS INSPIRATION POINT AND PORTUGUESE POINT TO LONG POINT. 

Portuguese tuff bed at landward end of Inspiration Point shows in middle distance. Irregular topography at right is part of landslide. Photograph by Palos Verdes Estates.

part of the Altamira shale in the Portuguese Canyon 

area. 

Tho south boundary of the breccia is obscured by 

talus. Inasmuch as the basalt sill and underlying silty 

and porcclancous shale exposed at the south edge of the 

talus are part of a section assigned on faunal and litho- 

logic grounds to the middle part of the Altamira shnle, 

it is inferred that the talus conceals a fault. 

FOSSItS 

K FORAMINIFERA 

Foram'mifcra were collected from the lower part of 

the Altamira shale in Portuguese Canyon at a horizon 

110 feet below the base of the Portuguese tuff. Through 

a,n error the horizon of this collection was cited in the 

preliminary paper 37 as 95 feet below the base of the 

Portuguese tuft. According to Kleinpell, these fossils 

suggest strongly the Siphogenerina branneri zone (zone 

A of preliminary paper), the upper zone in his Relizian 

stage. Foraminifcra from locality 2 in the Miraleste 

area and fr.om locality 2a in the Bluff Cove area are 

interpreted as representing the same zone. The species 

from these localities are given in the following table. 

Foraminifcra from lower -part of Altamira shale member of Mon- 

terey shale 

[Identifications by R. M. Kloinpell. R, Rnre; F, few; C, common] 

Species 

Bolivlna ad vena var. striatolla Cushman? _ .... 

Vnlvullnorin californica vnr. appressa Cushman. . 

VulvullMoria cnllforuica var. obosa Cushmnn _ .. 

Localities 

Siphogenerina branneri zone 

1 

R 

R 

R 

R 

0 

F 

C 

R 

2 

R 

C 

2a 

R 

F 

F 

F 

R 

F 

R 

F 

F 


Bluff 

Cove ' 

1 Saino locality ns 2a (soo p. 18). Hampton Smith, collector. This collection was 

.available through the kindness of D. D. Hughes. 

Klcinpcll's comments are summarized as follows: 

The fauna from the lower part of the Altamira shale 

suggests that this part of the Monterey in the Palos 

Verdes Hills is a local correlative of the Siphogenerina 

branneri zone. The fauna from the Palos Verdes Hills 

is closely related to that from the Gould shale member of 

the Monterey shale, the lowest member of the Monterey 

in the typo region of the Gould shale, on the west side of 

the San Joaquin. Valley. 38 Valvulineria ornata is not 

known from older horizons. The two varieties of 

Valvulineria californica, Hemicristellaria beali, and per 

haps Bolivina, imbricata range downward into the 

Siphogenerina hughesi zone, which underlies the zone 

represented by the Gould shale (Siphogenerina branneri 

zone), but are not known from older horizons. All the 

Foraminifera found in the lower part of the Altamira 

« WooclriiiR, W. P., Bramletto, M. N.. and Kleinpell, R. M., op. cit., p. 132. 

88 Barbat, W. F., Ago of producing horizon at Kettlcman Hills, Calif.: Am. Assoc. 

Petroleum Geologists Bull., vol. 16, pp. G11-G12, 1932. Kleinpell. R. M., Miocene 

stratigraphy of California, p. 121, Am. Assoc. Petroleum Geologists, Tulsa, Okla., 

1938.' Woodring, W. P., Stewart, Ralph, and Richards, R. W., Geology of the Ket- 

tloman Hills oil field, Calif.; stratigraphy, paleontology, and structure: TJ. S. Geol. 

Survey Prof. Paper 105, pp. 125, 137, 1940 [1941]. 

C 

c 

F 

C 

C 

R 

R 

shale range upward into the Siphogenerina reedi zone, 

overlying the Siphogenerina branneri zone, and all ex 

cept Valvulineria depressa range still higher. Therefore, 

the fauna from the Palos Verdes Hills may represent the 

Siphogenerina reedi zone rather than the Siphogenerina 

branneri zone. The abundance of Valvulineria califor 

nica var. appressa and also of typical Valvulineria de 

pressa suggests strongly, however, a correlation of the 

lower part of the Altamira with the Gould shale, as 

neither form is well developed at higher horizons. 

MIDDLE PART, INCLUDING MIRALESTE TUFF BED 

The middle part of the Altamira shale member is 

thicker than the other parts, is the most widely dis 

tributed division of the Monterey shale, and includes 

most of the cherty shale of the Monterey. In the Por 

tuguese Cany on-Altamira Canyon area it is 675 feet 

thick. On the north slope of the hills it overlaps the 

schist basement and has a thickness of about 400 feet. 

Beds of sandstone and conglomerate ranging in thick 

ness from a few feet to 75 feet are found at or near the 

base of the section in that region. 

Bentonitic tuffs are common in the middle part of the 

Altamira. A distinctive tuff characterized by the 

abundance of pumice lapillae was mapped on the north 

slope of the hills at a horizon 125 to 175 feet below the 

top of the middle part of the Altamira. Despite its 

thinness, this tuff is named, because it is one of the few 

distinctive lithologic units in the Monterey. It is desig 

nated the Miraleste tuff bed, 39 a name derived from the 

Miraleste residential district. The type region is along 

the west side of upper Agua Negra Canyon. The dark- 

brown pumice lapillae, commonly an inch or less in 

diameter, are embedded in a matrix of light-colored 

impure fine-grained volcanic ash. The pumice (index 

about 1.54) is more basic than the fine-grained ash of the 

matrix (index about 1.50). The Miraleste tuff is gener 

ally 2 to 4 feet thick, but at places is only a few inches 

thick and has a maximum thickness of 8 feet. Locally, 

dikelike extensions penetrate overlying and underlying 

strata. At several localities on the north slope of the 

hills there appear to be two beds of pumice tuff, but the 

apparent occurrence of two beds may be due to minor 

structural complications. 

.A zone of ellipsoidal opal concretions, similar to those 

in the Monterey of central California, 40 was found at 

scattered localities in the western half of the hills. The 

Miraleste tuff was recognized in the same section with 

the concretions at only one locality (column 6, pi. 3), 

where the concretions are about 100 feet above the tuff. 

At several other localities, however, there is some evi 

dence that the zone of concretions is at a uniform hori 

zon (columns 1, 2, 3, pi. 3). Should this suggestion be 

confirmed, the zone of concretions may be useful in 

working out details of the stratigraphy and structure 

in areas where they are now obscure. The localities 

where the concretions were recognized are shown on 

the geologic map (pi. 1). 

Characterized in general by the prevalence of cherty 

shale, the middle part of the Altamira includes, never 

theless, in some areas a varying thickness of. softer 

diatomaceous rocks. In the western half of the hills 

and on the south slope diatomaceous rocks were not 

found in this division of the Altamira. In the area on 

the north slope of the hills, extending approximately 

from Agua Negra Canyon to Miraleste Canyon, the 

39 Woodring, W. P., Bramlette, M. N., and Kleinpell, R. M., op. cit., p. 134. 

40 Taliaferro, N. L., Contraction phenomena in cherts: Geol. Soc. America Bull., 

vol. 45, pp. 194-207, pis. 13-24, 1934.

20 GEOLOGY AND PALEONTOLOGY OF PALOS VERDES HILLS, CALIFORNIA, 

Miraleste tuff is in a tongue of diatomaceous strata 50 

to 100 feet thick. Farther east, in and northwest of 

San Pedro, the middle division of the Altamira above 

the Miraleste tuff and also apparently as much as 200 

feet below the tuff consists principally of diatomaceous 

rocks. That is, there is an eastward and northward 

change from cherty rocks to softer diatomaceous rocks. 

That the change is due to iiiterfingering of the two rock 

types is inferred from the relations near, the crest of the 

hills south of Agua Negra Canyon, where the Miraleste 

tuff was traced southward across the crest. Westward 

on the south slope the tuff is progressively bentonitized, 

the pumice being the last consituent to be altered. In 

the area where the change hi character of the tuff takes 

place the tongue of diatomaceous rocks that includes 

the tuff in the Agua Negra Canyon district interfingers 

evidently with cherty shale. 

STRATIGRAPHY AND UTTHOL.OGY 

BLUFF COVE-MAIAGA COVE AREA 

The conglomerate and sandstone exposed near the 

top of the cliff at Bluff Cove (see fig. 5) are assigned 

arbitrarily to the middle part of the Altamira. The 

middle division of the Altamira. Foraminifera sug 

gestive of the Siphogenerina nucijormis zone were found 

in granular limestone at locality 10. The following 

section shows the lithology of the middle part of the 

Altamira above the limestone at locality 10 (column 1, 

pi. 3). 

Section of middle part of Altamira shale member of Monterey 

shale in sea cliff between Malaga Canyon and Flatrock Point 

Ft. in. 

31. Limestone. Overlain by phosphatic shale assigned 

to upper part of Altamira shale. For 

upward continuation of section see p. 29 ___ 

30. Chert, cherty shale, calcareous shale, and soft 

phosphatic shale._________________________ 

29. Limestone____________________ _______\. ______ 

28. Cherty and calcareous shale___'_______________ 

27. Limestone_____________-__-________________- 

26. Chert and cherty limestone.____--_--___-____ 

25. Soft shale containing a few phosphatic nodules 

and harder calcareous shale_'________________ 

24. Cherty and calcareous shale.-___.._.____-.___ 

23. Limestone________-'___-____-__-_-__---____ 

22. Chert, cherty shale, and thin zones of soft shale 

containing a few phosphatic nodules; layer of 

opal concretions 3 feet above base and scattered 

concretions at other horizons-.._______ 

3 

8 

3 

1 

2 

6 

2 

5 

4 

13 

.50 Feet 

FIGURE 6. Minor isoclinal anticline exposed in sea clifl a quarter of a mile southwest of mouth of Malaga Canyon. 

coarse-grained strata on the north limb of the Bluff 

Cove anticline, overlying the siltstone and silty sand 

stone assigned to the lower part of the Altamira, con 

tinue upward in the section to the thick basalt 'sill. 

The conglomerate consists principally of schist peb 

bles, and some beds contain angular pieces of schist 

in addition to pebbles. Molds of Anadara? and 

Aeguipecten were found in massive buff sandstone 

about 150 feet stratigraphically below the basalt sill 

(locality 2b). Irregularly oriented borings are abun 

dant in this sandstone. 

The strata in the cliff on the north limb of the syn- 

cline near Flatrock Point, overlying the basalt forming 

Flatrock Point, consist chiefly of cherty shale and 

limestone. They appear to be higher in the section 

than the conglomerate and sandstone just described, 

for it is improbable that the entire thickness of conglom 

erate and sandstone grades laterally so abruptly into 

cherty shale and limestone. The north boundary of 

the basalt forming Flatrock Point is probably marked 

by a fault, which, however, was not recognized inland. 

An essentially continuous section extending from the 

upper part of the middle division of the Altamira up 

ward into the Valmonte diatomite member is exposed 

in the sea cliff, from the crest of the minor anticline 

northeast of Flatrock Point northeastward to the 

mouth of Malaga Canyon. Soft calcareous shale, 

some of which contains phosphatic layers and nodules, 

is interbedded with cherty shale and limestone in the 

21. 

20. 

19. 

18. 

17. 

16. 

15. 

14. 

13. 

12. 

11. 

10. 

Limestone.._ ___---________-_-_____-- r ------ 

Chert, cherty calcareous shale, and thin-bedded 

limestone. _ _____________________________ 

Brecciated limestone._____-__--___-_______-__ 

Thin-bedded limestone, phosphatic shale, and 

cherty shale._____________________________ 

Crushed rock and debris of bentonitic tuff. 

Thickness uncertain.______________________ 

Shale containing light-colored phosphatic string 

ers, cherty shale and tuff.______-___-_-_-_-_ 

Thin-bedded limestone, calcareous shale, and 

cherty shale._____________________________ 

Shale containing light-colored phosphatic string 

ers, and cherty shale_______________________ 

Limestone.. _ ________________________________ 

Calcareous and cherty shale__________________ 

Brecciated limestone_______________________ 

Calcareous shale containing light-colored phos 

phatic stringers, and cherty shale.___________ 

Thin-bedded limestone.______________________ 

Calcareous and cherty shale__________________ 

Brecciated limestone.________________________ 

Shale containing few phosphatic nodules.______ 

Limestone-_ ________________________________ 

Calcareous and cherty shale._________________ 

Brecciated limestone.________________________ 

Brown bituminous (?) shale___________________ 

Limestone. A granular layer at top contains 

Foraminifera suggestive of Siphogenerina nu- 

ciformis zone (locality 10)____-_____-_-_-_._ 

23 9 

Ft. 

4 0 

15(?) 0 

3 0 

Thickness of section_____________________ 146± 0 

The total thickness given for the preceding section 

is of doubtful value, because unit 17 is represented by 

3 9 

0 

6 

0 

10

slide debris that may conceal a fault. A thickness of 

15 feet is assigned to unit 17, and it is assumed that 

there is no gap or duplication in the stratigraphic 

succession. Immediately north of the slide the strata 

are folded in a narrow isoclinal anticline (fig. 6). The 

strong deformation appears to have been localized by 

be.ntoni.tic tuff, which may have acted as a lubricant. 

If the opal concretions in unit 22 of the preceding section 

arc at tnc same horizon as similar concretions elsewhere 

in undisturbed sections, this tuff, the presence of which 

is indicated by slide debris, is younger than the Miral- 

esto tuff. 

In the Malaga Cove residential district inland from 

the coast the middle part of the Altamira shale, con 

sisting chiefly of cherty shale, porcelaneous shale, and 

limestone, can be seen in highway cuts and natural 

exposures. A tuff about 60 feet thick exposed on Del 

Monte road near La Venta Inn consists of soft benton- 

itic material in the upper part and hard silicified tuff 

in the lower part. Opal concretions were observed in a 

highway cut southeast of the Malaga Cove business 

district and on the north limb of a steeply folded anti 

cline in the upper part of Valmonte Canyon. 

BLUFF COVE-LUNADA BAY AREA 

A virtually continuous section complicated by minor 

folds extends from a horizon apparently low in the 

middle part of the Alta,mira shale upward to the Val- 

monto diatomite in the sea cliff between Bluff Cove and 

Lun ada Bay. Fo.ramin.if era from limestone immediately 

overlying the basalt sill, at locality 3, on Palos Verdes 

Drive West, near Bluff Cove, are assigned to the Sipho- 

generina reedi zone. Foraminifera were observed also 

in Imrd baked limestone underlying the basalt sill on 

the sea cliff. The limestone at locality 3 contains 

broken large bones, presumably whale remains. Beds 

of limestone at the same horizon form low-tide reefs 

at the foo* of the sea cliff, 2,100 feet west-southwest of 

locality 3. (See pi. 26.) Huge concretionary hard 

masses weathered out of the reefs contain large bones 

like those at locality 3. A field sketch of a skull ex 

posed in longitudinal section suggests, according to 

Dr. Remington Kellogg, a whalebone whale. 

Silty shale and porcelaneous shale overlie the bone- 

bearing reefs. Still higher in the section is the main 

cherty shale zone of the Monterey, with which many 

beds of limestone are interbedded. Toward the top of 

the section calcareous mudstone and soft shale,, both 

containing pb.osph.atic nodules, are interbedded with 

the cherty shale, forming a transition zone to the 

bituminous and phosphatic shale assigned to the upper 

part of the Altamira, the base of which is about 2,000 

loot northeast of Palos Verdes Point. 

LUNADA BAY-POINT VICENTE AREA 

The middle part of the Altamira reappears under 

lying the upper part of the member on the south limb 

of the main syncline at Lunada Bay. Loose limestone 

concretions along the beach, on the north side of Resort. 

Point, contain cetacean remains. These concretions 

probably weather out of the limestone interbedded 

with calcareous phosphatic siltstone that forms reefs 

along the shore. The area southward to Point Vicente 

and beyond toward the east is characterized by the 

abundance of basalt. At many places the present sea 

cliff and also the cliff at the seaward edge of the second 

terrace inland are capped by hard limestone and cherty 

shale overlying basalt. 


A tuff about 40 feet thick is exposed in the second 

cove south of Resort Point. It consists of light- 

colored bentonitic material containing glass shards 

toward the top. This tuff is evidently in the lower 

part of the middle division of the Altamira and may 

correspond to. the 60-foot tuff in the Bluff Cove-Malaga 

Cove area. Tuff of comparable thickness was not 

recognized in areas where the stratigraphic succession 

is more definite, unless the tuff at these two localities 

corresponds to the Portuguese tuff. 

ALTAMIRA CANYON-PORTUGUESE CANYON AREA 

The best section of the middle part of the Altamira 

shale is found along Altamira Canyon and its tribu 

taries, where the structure is simple and the rocks are 

generally well exposed. A section measured in the 

east fork of Altamira Canyon follows. (See column 3, 

pi. 3, measured in canyon at right edge of view on pi. 4.) 


shale in east fork of Altamira Canyon 

Ft. n. 

102. Laminated siliceous limestone, overlain by soft 

silty shale and nodular phosphatic shale 

assigned to upper part of Altamira shale. For 

upward continuation of section see p. 31-___ 

101. Porcelaneous shale-_----_________-_.___--__ 

100. Soft, somewhat silty, porcelaneous shale__---_- 

99. Limestone_--______________________________ 

98. Rusty altered tuff (?)-____________-_________ 

97. Silty shale._____-_.:._.._________.__ 

96. Laminated limestone.______________________ 

95. Porcelaneous shale.________________________ 

94. Altered tuff____._._.________-_______--_ 

93. Soft, somewhat silty, porcelaneous shale_--__ 

92. Cherty shale____________...__________-.._ 

91. Limestone---____----_-_____-___---__--_--- 

90. Soft, somewhat silty, porcelaneous shale__-_--- 

89. Cherty shale; 3 layers of opal concretions. _ _ _ _ 

88. Shale, softer and more silty than unit 86______ 

87. Siliceous limestone_-----_-______--_____---_ 

86. Porcelaneous shale.-_---___--_-_--_-----_-- 

85. Siliceous limestone._-________-_---_-_-_-_-_ 

84. Cherty shale_____________________________ 

83. Soft, somewhat silty, porcelaneous shale.------ 

82. Lenticular limestone._______________________ 

81. Rhythmically bedded porcelaneous shale, units 

several inches thick_______________________ 

80. Reddish altered tuff----__--_--_-------_---- 

79. Brown phosphatic shale_-________--____----_ 

78. Granular limestone.______-_-_-_---_-___-_-_ 

77v Soft, somewhat silty, porcelaneous shale__-_-__ 

76.'Granular limestone.________________________ 

75. Soft, somewhat silty, porcelaneous shale.______ 

74. Cherty shale__________________--_-_-_---- 

73. Soft, somewhat silty, porcelaneous shale-_-_--_ 

72. Cherty shale-________________________ 

71. Altered tuff (?)___-__---_---_-----------_-- 

70. Porcelaneous shale_--__-___---------------- 

69. Limestone containing poorly preserved Foraminifera 

of uncertain zonal position in Kleinpell's 

Luisian stage (locality 3a)__-_____--__ 

68. Soft, somewhat silty, porcelaneous shale____-__ 

67. Rhythmically bedded porcelaneous shale._____ 

66. Soft, somewhat silty, porcelaneous shale __ 

65. Dense limestone containing Valvulineria. ___.__ 

64. Alternating soft silty shale and harder porcelaneous 

shale.__-_----------_--------_--- 

63. Limestone.-------------------------------- 

62. Alternating soft silty shale and harder porcelaneous 

shale; 1% feet above base a 2-inch altered 

tuff. Fifty feet down canyon 1 foot + 

of altered mottled tuff at base; probable 

equivalent of Miraleste tuff bed---_.___-_-_ 

61. Cherty shale____________.___---_-_.-_---- 

60. Silty shale .------------------------- ---- 

59. Limestone.-------------------------------- 

58. Porcelaneous and silty shale_______._____-_-- 

1 

4 

4 

2 

1 

2 

2 

3 

1 

2 

9 

2 

1 

3 

9 

2 

2 

7 

4 

7 

2 

4 

1 

1 

1 

2 

2 

3 

5 

3 

4 

7 

2 

1 

8 

3 

19 

3 

3 

4 

1



shale in east fork of Altamira Canyon Continued 

Ft. in. 

57. 

56. 

55. 

54. 

53. 

52. 

51. 

50. 

49. 

48. 

47. 

46. 

45. 

44. 

43. 

42. 

41. 

40. 

39. 

38. 

37. 

36. 

35. 

34. 

33. 

32. 

31. 

30. 

29. 

28. 

27. 

26. 

25. 

24. 

23. 

22. 

21. 

20. 

19. 

18. 

17. 

16. 

15. 

14. 

13. 

12. 

11. 

10. 

9. 

8. 

7. 

6. 

5. 

4. 

3. 

Tuffaceous (?) clay_________________________ 1 

Porcelaneous and silty shale__-__-_______--_- 4 0 

Unexp.osed; probably mostly tuff ____________ 10 0 

Altered white tuff______________________ 2 + 0 

Porcelaneous shale_-__-_-__--_------____-_- 5 0 

Limestone__-___-____-____-_-___--_-____--_ 1 10 

Silty shale________________________________ 1 5 

Soft porcelaneous shale.____--_--_--_____--- 4 0 

Bentonitic clay___ _________________________ 2 

Silty and soft porcelaneous shale _____________ 5 6 

Porcelaneous shale and limestone.____________ 1 6 

Poorly exposed; mostly silty shale ___________ 5 0 

Limestone_______________________________ 3 0 

Poorly exposed silty and porcelaneous shale. __ 6 6 

Cherty shale________-___-_-_____-_____-_- 6 

Silty shale___---._____.___________-_____--- 2 0. 

Porcelaneous shale________________________ 5 4 

Siliceous limestone and cherty shale __________ 2 0 

Cherty shale________________________ 1 0 

Silty shale_____._____________________,______ 4 0 

Rhythmically bedded porcelaneous shale._____ 4 0 

Laminated siliceous limestone______________ 3 0 

Silty shale___________-______..______________ 5 0 


Fissile silty shale and soft porcelaneous shale. .5 3 

Fine-grained dolomite (?)__________________ 5 


Bentonitic clay_____________________________ 1 4 

Silty shale.____________________________ 1 0 

Fine-grained dolomite (?)__________________ 3 0 

Fissile silty shale.__________________________ 1 2 

Porcelaneous shale._________________________ 3 10 

Poorly exposed silty shale.__________________ 9 0 

Dense limestone____________________________ 3 

Porcelaneous shale 2 feet thick grading upward 

into silty and calcareous shale _____________ 4 ' ;4 

Fine-grained sandstone____________________ 2 

Siltstone. _________________________________ 1 1 

Limestone_________________________________ 1 7 

Porcelaneous shale__________'______________ 8 

Limestone______'______^_____.______________ 4 

Reddish tuffaceous (?) clay.______._______ ___ 5 

Silty porcelaneous shale_____________________ 2 2 

Hard cherty shale._________________________ 6 0 

Reddish tuffaceous (?) clay__________________ 2 

Siltstone____---___________________________ 6 3 

Laminated porcelarieous shale, dark brown or 

black when fresh.________________________ 5 '0 

Reddish tuffaceous (?) clay.-_-_-_________-__ 6 

Siltstone____----____-_____________________ 4 0 

Dense limestone____________________________ . 6 

Principally porcelaneous shale______________ 5 0 

Siltstone_____-____________-________________ '1 -4 

Dense siliceous limestone containing diatoms. _ 2 

Siltstone_____-____._______________________ 2 0 

Porcelaneous shale_________________________ 1 ' 6 

Scattered exposures, more numerous upward, 

of porcelaneous shale rhythmically bedded 

with fine-grained dolomite (?) and a few beds 

of limestone. Thickness computed_________ 80 0 

Unexposed. On hillside scattered exposures of 

porcelaneous shale, thin-bedded fine-grained 

dolomite (?), and limestone. Thickness com 

puted_________________________________ 133 0 

Unexposed. Thickness computed. Underlain 

by Portuguese tuff bed, which is not clearly 

exposed. Water seep at estimated top of bed 150 0 

Thickness of section_._---_.____________ 670 0 

The preceding section includes many thin beds of 

bentonitic tuff. The mottled tuff in unit 62 was se 

lected as the probable equivalent of the Miraleste tuff 

bed by tracing limestone ledges between the canyon and 

the westernmost exposure of the Miraleste tuff 1,000 feet 

east of the canyon. Opal concretions were found in a 

9-foot cherty shale (unit 89) 35 feet below the top of the 

middle part of the Altamira and 110 feet above the 

probable equivalent of the Miraleste tuff. Basalt, 

which is abundant to the east and to the west, was not 

found along the east fork of Altamira Canyon. Sand 

stone is rare but farther east occurs in thick beds. 

AGTTA NEGBA CANYON AREA 

The Agua Negra Canyon area includes the area 

drained by Agua Negra Canyon and its tributaries and- 

adjoining parts of the north slope of the hills. In this 

region the Miraleste tuff bed is in a tongue of soft dia- 

tomaceous rocks about 50 feet thick. The following 

section was measured on the west slope of upper Agua 

Negra Canyon in the type region of the Miraleste tuff 

(see pi. 7, A). 

Section of middle part of Altamira shale member of Monterey shale, 

including Miraleste tuff bed, on west side of upper Agiia Negra 

Canyon 

Ft. in. 

29. Laminated diatomite penetrated by several tuff 

dikes. Top not exposed___________________ 10+ 0 

28. Mirale'ste tuff bed: 

c. Fine-grained massive tuff containing many 

fragments of dark-colored pumice having 

an average length of half an inch and a 

maximum length of about an inch; includes 

slabs of diatomite and limestone (maxi 

mum length about a foot) lying in various , 

attitudes; basal contact slightly irregular. 3 8 

b. Laminated diat,omite____________________ 6 

a. Tuff like unit c; basal contact slightly irreg 

ular. _________________________________ 7 

27. Laminated diatomite.__---_----_-__-__------ 6 0 

26. Limestone____________--____--_____--___---_ 1 2 

25. Laminated diatomite penetrated by a 1-foot 

pumice tuff dike inclined at an angle of about 

30° to bedding..__...____________.________ 11 0 

24. Siliceous limestpne. __-______-_-.___---_----_ 0 5 

23. Thin-bedded diatomaceous limestone-_________ 0 11 

22. Laminated diatomite; grades upward into over 

lying limestone____---________L_--_--_-i_ 4 4 

21. Poorly exposed soft laminated shale; a few dia-° 

tomsin somelayers, many in others.------.-- 3 6 

20. Porcelaneous shale; soft layers in upper part..._ 8 0 

19. Unexposed____-__-_-_----------___--__----. 8 0 

18. Porcelaneous shale; upper part silty____.___-__ 1 10 

17. Poorly exposed thin-bedded silty shale_-___-__- 5 6 

16. Siliceous limestone; upper part silty limestone __ 1 6 

15. Porcelaneous shale.__.-----_---.--_--------_ 12 0 

14. Breccia bed. Fine-grained sandy calcareous silt- 

stone containing slabs of porcelaneous shale 

lying in various attitudes; maximum length of 

slabs about 6 inches._____ _________________ 3 4 

13. Rhythmically bedded porcelaneous and silty 

- shale..._.-_---._..__..-_-..-___-_-__--_ 5 2 

12. Hard very siliceous laminated limestone grading 

upward into chert; forms base of cliff (see pi. 

7, A, atright)_______---____--___--__ ___ 1 7 

11. Poorly exposed rhythmically bedded porcela 

neous and silty shale_----__---__------------ 20 0 

10. Siliceous limestone.__.----_-----__---------- 2 0 

9. Poorly exposed rhythmically bedded porcela 

neous and silty shale; units 5 to 10 feet thick. 

Zones of porcelaneous shale, where well ex 

posed, themselves show rhythmic bedding of 

more siliceous and less siliceous shale on a 

smaller scale; units a few inches thick_-_---_ 45 0 

8. Porcelaneous shale. ___-_-__-_---_-_--------- 6 0 

7. Thin-bedded silty shale, sandy shale, and fine 

grained sandstone..._-._____-___---------- 10 0 

6. Porcelaneous shale; few layers 1 to 2 inches thick 

of denser cherty shale.___________--_-- ---- 16 0 

5. Hard laminated cherty shale__.____-__-----_ 2 6 

4. Thin-bedded shale, lower half more siliceous than 

upper half _______________._.______------- 9 0 

3. Dense laminated chert----------------------- 10 

2. Imperfectly exposed hard porcelaneous shale con 

taining many fish scales. ___-___-_---------- 23 0

Section of middle part of Altamira shale member of Monterey shale, 

including Miraleste tuff bed, on west side of upper Agua Negra 

Canyon Continued 

1. Thin-bedded silty and porcelaneous shale; ex 

posed .in cut bank at canyon floor, 

e. Rhythmically bedded shale; units of 

sandy shale grading upward into por- Ft. in. 

celaneous shale...------------------ 2 10 

d. Silty shale....--.-------------------- 1 0 

c. Porcelaneous shale_______--___--_----_ 1 7 

b. Medium-grained sandstone ____________ 1 6 

a. Porcelaneous shale.__..________________ 7 

Thickness of section...______--__-_--_____ 230 10 

As shown in the preceding section, the strata in this 

area underlying the tongue of diatomaceous shale and 

diatomite associated with the Miraleste tuff, comprising 

an exposed thickness of about 200 feet, consist chiefly 

of porcelaneous shale. Sandstone is rare and is gen 

erally absent. 

The Miraleste tuff varies in thickness from a few 

inches to several feet within short distances. The max 

imum thickness is generally 3 to 4 feet, exceptionally 

6 to 8 feet. The dark-colored pumice lapillae embedded 

in the light-colored matrix vary in length from a fraction 

of an inch to 2 inches. At many localities the tuff has 

been squeezed into cracks and along bedding planes in 

the underlying and overlying soft rocks, dike-like and 

sill-like bodies of tuff extending through a thickness of 

as much as 15 to 30 feet. As may be seen on plate 7, A, 

the soft diatomite interbedded with the Miraleste tuff 

is irregularly deformed toward the south end of the cliff 

where the preceding section was measured, whereas the 

underlying harder strata have a uniform gentle dip. 

Locally the matrix of the tuff is calcified, forming a 

hard limy bed speckled with pumice. 

The strata in the middle part of the Altamira shale 

overlying the diatomaceous rocks interbedded with the 

Miraleste tuff are about 125 feet thick. They include 

porcelaneous shale and cherty shale as well as softer 

shale that is generally poorly exposed, but the propor 

tion of hard siliceous shale decreases eastward. Opal 

concretions were found in cherty shale about 100 feet 

above the Miraleste tuff on the Crest Road at the head 

of Sopulvcda Canyon (column 6, pi. 3) and at scattered 

localities west of Agua Negra Canyon. They were not 

observed farther to the north or east, but at many places 

a conspicuous zone oi; chert and cherty shale is in the 

same part of the section approximately 100 feet above 

the Miraleste tuff. Fragmentary large bones, presum 

ably cetacean remains, occur in limestone 25 feet above 

the Miraleste tuff at a locality 0.4 mile west of Agua 

Negra Canyon. 

GEORGE F CANYON-MIRALESTE CANYON AREA 

Along George F Canyon and its tributaries strata 

assigned to the middle part of the Altimira shale rest 

on the schist basement (column 7, pi. 3), conglomerate 

and sandstone of varying thickness lying on the schist 

surface. The conglomerate contains slightly rounded 

or angular pieces of schist that have a maximum length 

of 6 to 12 inches. The sandstone is buff on fresh sur 

faces and reddish brown on weathered surfaces. Oh 

the 862-foot hill on the west side of George F Canyon a 

thickness of about 10 feet of conglomerate is exposed. 

At places in the main schist area the conglomerate and 

sandstone are evidently thin, as cherty shale is exposed 

within a few feet of the schist. Sandstone about 75 

feet thick overlies the small area of schist exposed along 

the crest of an anticline in the first canyon east of Palos 

Verdes Drive East. Other outcrops of sandstone were 


found along this anticline in the next canyon to the 

south, a tributary of Miraleste Canyon. The schist is 

not far below the surface in this region, for it was pene 

trated in the Whites Point sea-level tunnel on the crest 

of the same anticline 470 to 500 feet below the surface 

(section E E', pi. 1). In the tunnel conglomerate 

having a thickness of 50 to 60 feet and consisting of 

imperfectly rounded green schist pebbles 1 to 6 inches 

long overlies the schist on the north limb of the anti 

cline. On the south limb similar conglomerate is about 

50 feet thick and is overlain by about 25 feet of massive 

greenish sandstone containing a few angular pieces 

of schist. 

The schist is probably close to the surface also west 

of George F Canyon. Conglomerate containing schist 

cobbles and slabs as much as a foot long is exposed along 

Crenshaw Boulevard in the Rolling Hills district, 800 

feet south of the syncline containing the Miraleste tuff. 

Turritella ocoyana and other mollusks were collected 

from sandstone overlying schist at locality 13, on the 

west slope of George F Canyon, 20 feet above the canyon 

floor. The fossiliferous strata are estimated to be 40 

feet above the top of the schist and 225 feet below the 

Miraleste tuff. A few mollusks were found also near 

the top of the sandstone along the first canyon east of 

Palos Verdes Drive East (locality 13a). 

The exposed strata between the coarse-grained detri- 

tal rocks at the base of the section and the soft diatoma 

ceous rocks interbedded with the JVfiraleste tuff consist 

generally of cherty shale and limestone. Light-colored 

bentonitic tuff is exposed about 150 feet below the Mira 

leste tuff on the west slope of George F Canyon. 

Similar material is found on the 918-foot hill west of 

the canyon. The rocks penetrated in the Whites Point 

tunnel show that soft shale and siltstone are more 

abundant in this part of the section than is apparent 

from surface exposures. Some of the siltstone contains 

phosphatic nodules, and a few thin layers of blue-schist 

sandstone are interbedded with the siltstone Along 

Miraleste Canyon outcrop relations between cherty 

shale and overlying diatomaceous rocks were interpreted 

as indicating a fault with downthrow to the north. 41 

According to observations in the tunnel the strata are 

in normal sequence. The outcrop relations are 

probably to be attributed to sharp folds and minor 

displacement. 

Owing to inadequate exposures and minor structural 

cpihplications, the Miraleste tuff was not mapped con 

tinuously east of George F Canyon. On the north limb 

of the minor anticline extending across George F Canyon 

and at localities farther southeast there appear to be 

two beds of pumice tuff, possibly due to dike-like and 

sill-like extensions of the tuff or to duplication by minor 

folds or faults. 

As in the Agua Negra Canyon area, the Miraleste 

tuff is interbedded with diatomaceous rocks. Lenses 

of limestone in the diatomaceous rocks contain molds 

of Siphogerierina and Valvulineria. In the district 

between Palos Verdes Drive East and Miraleste Canyon 

diatomaceous strata, with which some cherty shale is 

interbedded, extend evidently both higher and lower in 

the section than in the area farther west. Though the 

Miraleste tuff was not observed in the Whites P.oint 

tunnel, the stratigraphic relations of the diatomaceous 

shale penetrated in the .tunnel indicate that the division 

between hard cherty shale and softer diamaceous rocks 

is about 200 feet below the projected horizon of the 

24 

Miraleste tuff. On the preliminary geologic map 42 

part of the diatomaceous rocks overlying the Miraleste 

tuff was assigned to the Valmonte diatomite. That 

member is now thought to be overlapped by the Plei 

stocene San Pedro sand and Lomita marl. 

MIBALESTE-SAN PEDRO HHI AREA 

In the deep canyons on the south slope of San Pedro 

Hill and in Averill Canyon beds of sandstone, some of 

which contain lenses of conglomerate made up chiefly 

of schist pebbles, are conspicuous constituents of the 

middle part of the Altamira. Altered diatoms occur 

in a thin zone included in moderately soft laminated 

shale exposed on Palos Verdes Drive East, about 40 

feet stratigraphically above the thick basalt sill on the 

south limb of the Miraleste anticline. Foraminifera 

from silty- shale at locality 4, on Crest Koad, are 

assigned doubtfully to the Siphogenerina reedi zone. 

A Collection from buff siltstone at locality 11, south 

east of San Pedro Hill, is assigned to the Siphogenerina 

nuciformis zone. 

East of the Cabrillo fault the Miraleste tuff is exposed 

on the road leading from Ninth Street to Miraleste 

and at two nearby localities in a tributary of San 

Pedro Canyon, where there are many minor folds. 

Diatomaceous silt at locality.5 contains Foraminifera 

of the Siphogenerina reedi zone. In San Pedro Canyon 

and its tributaries isolated outcrops show cherty shale 

and limestone dipping in various directions. The 

structure and stratigraphy are obscure, but presumably 

these strata underlie the Miraleste tuff. 

The rocks penetrated in the Whites Point tunnel in 

the Miraleste area north of the Cabrillo fault, consist 

of shale containing many thin beds of greenish sand 

and siltstone containing scattered phosphatic nodules. 

Two thin sills of altered basic igneous rock, one of 

which is too thin to be shown on the structure section 

(section E E', pi. 1),, were encountered. South of the 

Cabrillo fault, beds of greenish sandstone and conglom 

erate several feet thick, containing schist pebbles as 

much as 6 inches long, are interbedded with silt- 

stone. Higher in the section phosphatic siltstone, thin 

beds of sandstone, cherty shale, and limestone were 

encountered. 

SAN PEDRO AREA 

The Miraleste tuff was .recognized in a ravine ad 

joining the west edge of Peck Park in the northwestern 

part of San Pedro and also in the next canyon to the 

north. At both localities there appear to be two beds 

of tuff. Foraminifera of the Siphogenerina reedi zone 

were found in steeply dipping calcareous sandstone at 

locality 7, on the north side of the main ravine in Peck 

Park, opposite a great mass of chert on - the south side. 

The steeply dipping strata are probably faulted against 

flat-lying diatomaceous shale cropping out upstream. 

Downstream diatomaceous shale and limestone are 

presumably in the same part of the section as the 

diatomaceous shale upstream. 

Along San Pedro Canyon and its main tributary, 

just north of Seventh Street, the complexly folded 

cherty shale and limestone mentioned under the head 

ing "Miraleste-San Pedro Hill area" are overlain by 

diatomaceous silt and limestone, with which some 

cherty shale is interbedded. The lower part of the 

diatomaceous silt contains pebbles and slabs of schist. 

The largest pebble observed has a length of 10 niches, 

«Idem. « 

but an occasional slab of schist is as much as 2 feet 

long. Even as far east as a locality in San Pedro 

Canyon 300 feet upstream from the projection of 

Leland Avenue diatomaceous silt contains pieces of 

schist a foot long. Foraminifera from the lower part 

of the diatomaceous silt at locality 6 represent a fauna 

of small, possibly immature forms assigned doubtfully 

to the Siphogenerina reedi zone. The diatomaceous 

silt at locality 6 is estimated to be at about the horizon 

of the Miraleste tuff, which, however, was not found 

in this area nor farther south. 

Diatomaceous silt, limestone, and thin beds of blue- 

schist sandstone exposed along Averill Canyon and 

nearby in western San Pedro represent presumably the 

same part of the section as that just described. 

The relative abundance in the San Pedro. area of 

diatomaceous silt in strata now assigned to the middle 

part of the Altamira led to the assignment of part of. 

this section to the Valmonte diatomite.member on the 

preliminary geologic map. 43 

POINT FERMIN AREA 

In the Point Fermin area the upper part of the 

Altamira shale includes a coarse-grained detrital facies, 

less phosphatic shale, and more cherty shale than 

elsewhere. Consequently lithologic differentiation 

between the middle and upper parts of the member 

is indefinite. One lithologic type, however, may serve 

in distmg-ukhirig the two parts of the Altamira. 

Wherever!massive siltstone was found it is referable 

to the middle part on both stratigraphic and faunal 

grounds. In the sea-cliff section on the east side of 

Point Fermin the base of the upper part of the Altamira 

is drawn, arbitrarily at the base of the lower of the 

two thick units of blue-schist sandstone. 

The strata along the Point Fermin anticline inland 

from the coast consist of thin-bedded blue-schist 

sandstone, silty shale, siltstone, cherty shale, and thin 

beds of phosphatic shale. The sandstone is generally 

medium-grained. Locally, however, it is coarse-grained 

and conglomeratic, as at Thirty-fifth Street and Patton 

Avenue, where a 1-foot bed contains pebbles and 

angular pieces of schist half an inch long. Foraminifera 

assigned to the Siphogenerina collomi zone were 

collected from massive buff siltstone at locality 12, 

on Alma Street. 

Porcelaneous shale, silty shale, calcareous phosphatic 

shale, and minor beds of blue-schist sandstone form the 

100-foot cliff along the crest of the Point Fermin anti 

cline where it emerges on the coast. A thin layer of 

silty shale about 4 feet above the foot of the cliff 

(locality 8) yielded a collection of small, possibly 

immature, Foraminifera assigned doubtfully to the 

Siphogenerina reedi zone. The stratigraphic relations 

of these strata to those in western San Pedro north of 

the Cabrillo fault are doubtful, but they are presum 

ably the equivalent of part of the section in western 

San Pedro that includes much diatomaceous silt. A 

local discontinuity or a bedding-plane fault was visible 

formerly at the foot of the cliff, about 100 feet east of 

the abandoned oil well (pi. 7, B). 

The Cabrillo fault is well exposed in the sea cliff 

(pi. 6, .D). South of the fault are massive buff silt- 

stone and lenticular limestone in the middle part of the 

Altamira; to the north are porcelaneous shale, phos- 

« Woodring, W. P., Bramlette, M. N., and Kleinpell, B. M., op. cit. (Am. Assoc. 

Petroleum Geologists Bull., vol. 20), pp. 128-129), fig. 1.

pi) a tic shale, and limestone in the upper part of the 

Altamira. The buff siltstone contains Foraminifera 

typical of the Siphogenerina reedi zone (locality 9). 

The relations between the buff siltstone and the strata 

on the crest of the Point Fermin anticline at locality 8 

arc obscured by talus in the intervening area, but the 

siltstone is presumably younger. 

In San Pcdro, north of the Fort McArthur Upper 

Reservation and north of the Cabrillo fault, blue- 

schist sandstone, porcelaneous shale, and silty shale are 

exposed irt street cuts. These strata appear to grade 

northwestward into those including diatomaceous silt, 

described on page 24. 

WHITES POINT AREA 

No satisfactory lithologic basis for separating the 

middle and upper pa.rts of the Altamira was discovered 

in the Whites Point area. In the preliminary paper 44 

pprcelaneous shale and silty shale containing Forami 

nifera of the Holivina modeloensis zone at localities 14 

and 15 were referred on lithologic grounds to a posi 

tion near the top of the middle part of the Altamira. 

According to the classification now adopted, however, 

the strata are assigned to the upper part on the basis 

of the faunal data. 

Stratigraphic relations in the strongly deformed 

rocks at Whites Point and0 nearby are obscure. The 

schist conglomerate, sandstone, and silty shale in the 

core of the fan-shaped anticline near Whites Point, 

shown in figure 14, and in the anticlinal reefs at the 

point probably represent the middle part of the Alta 

mira. An incomplete mold of Aeguipecten was col 

lected from sandstone overlying, schist conglomerate 

on the north limb of the anticline (locality 12a). In 

the reefs 2,000 feet northwest of Whites Point rounded 

masses of basalt are embedded in a limy matrix con 

taining basaltic .debris and fragments of pectens. 

This material represents intrusion under a thin cover 

of unconsolidated sediments or a submarine flow. 

The oldest rocks exposed on the anticline emerging on 

the coast half a mile northwest of White"s Point consist 

of siltstone, mudstone, limestone, and a little porcela- 

neous shale. These strata, about 100 feet thick, and an 

overlying unit about 25 feet thick, mostly porcelaneous 

shale, are thought to represent the middle part of the 

Altamira. Foraminifera suggestive of the Siphogenerina 

nuciformis zone were found in calcareous mudstone 

exposed at low tide 1.2 miles northwest of Whites Point 

(locality 12b). Loose limestone masses among the reefs 

at that locality contain cetacean remains. Well- 

preserved Foraminifera, including Siphogenerina and 

Valvulineria, were found recently on the extension of 

Twenty-fifth Street, 0.45 mile southeast of the junction 

with Palos Verdes Drive South.. 

In the Whites Point area the WThites Point tunnel 

penetrated strata consisting of siltstone, some of which 

contains hard phosphatic nodules, cherty shale, lime 

stone, and thin beds of clay. The rocks are strongly 

deformed in the part of the tunnel between the coast 

and a locality 0.3 mile inland. Poorly preserved 

Foraminifera of uncertain zonal position in Kleinpell's 

Luisian stage were collected 250 and 355 feet north of 

the south portal (localities 12c and 12d, respectively). 

At the outermost edge of the offshore reefs the open cut 

exposed buff sandstone underlying basaltic rocks. 

A diver brought up schist conglomerate about 100 feet 

beyond the edge of the reefs. 

« \Voodrinjt, W. P., Bramlctte, M. N., and Klcinpoll, R. M., op. cit., pp. 135,142. 


FOSSILS 

FORAMINIFERA 

Foraminifera were collected from the middle part 6f 

the Altamira shale at the localities given in the following 

table. At many other localities molds of Siphogenerina 

and large Valvulineria were observed, particularly in 

limestone interbedded with soft rocks near the horizon 

of the Miraleste tuff. These forms may be recognized in 

the field and. are not known to occur in the upper part 

of the Altamira shale or at higher horizons. 

The collections from the middle part of the Altamira 

are assigned by Kleinpell to his Luisian stage. The 

preservation of much of the material is poor, and 

the zonal position at many localities is uncertain. 

According to Kleinpell's identifications, however, the 

three zones in his Luisian stage in ascending order 

the Siphogenerina reedi, S. nuciformis, and S. cotlomi 

are represented. No evidence is apparent for the 

relative Stratigraphic position of the three zones in the 

Palos Verdes Hills. The S. reedi zone appears to extend 

up to about the Miraleste tuff. Foraminifera character 

istic of that zone were found at locality 5 in diatomace 

ous silt, evidently near the horizon of the Miraleste tuff. 

It may be expected that the S. nuciformis and S. collomi 

zones are in the uppermost part of the middle division 

of the Altamira. Stratigraphic control at the localities 

where these two zones are identified is lacking. Locality 

10, where a few species suggestive of the S. nuciformis 

zone were found, appears to be rather low in the section 

for that zone. (See pi. 3.) The Stratigraphic data at 

that locality are, however, uncertain. 

The species identified by Kleinpell are given in the 

table on the following page. 

Kleinpell's comments on these fossils are summarized 

as follows: 

The Foraminifera from the middle part of the Alta 

mira shale are generally poorly preserved. The preser 

vation of the Siphogenerinas, which might give a clue 

to zonal position, is particularly poor in most of the 

collections including that genus. The best preserved 

material may be referred to the Luisian stage (group 2 

of preliminary paper) ,45 which corresponds to the unde 

fined Valvulineria californica zone in its most restricted 

sense. 

The collections from localities 3a, 12c, and 12d con 

sist of a few poorly preserved species. Their zonal 

position in the Luisian stage is uncertain. Foraminifera 

from localities 4, 6, and 8 are assigned doubtfully to the 

Siphogenerina reedi zone (zone B of preliminary paper). 

Localities 6 and 8 are referable to the S. reedi zone or 

the underlying S. branneri zone, or possibly to even 

somewhat older zones. Locality 4 may be referred to 

either zone just mentioned but hardly to any older 

horizon. All three localities appear to be referable to 

the S. reedi zone rather than to older zones on the 

basis of rather indefinite field relations. A peculiar 

faunal facies, in which all the species are represented by 

very small possibly immature specimens, occurs at 

localities 6 and 8. Assemblages from localities 5 and 9 

are typical of the S. reedi zone, and the assemblage from 

locality 3 appears to represent that zone. A sample 

that seems to be a duplicate of that from locality 3 

contains Valvulineria californica. The assemblages 

from localities 3, 5, and 9 may be correlated with the 

typical fauna of the S. reedi zone of the Monterey 

« Wooclring, W. P., Braralotco, M. N., and Kleinpell, R. M., op. cit., pp. 125-149.


Foraminifera from middle part of Allamira shale member of Monlerey shale 

[Identifications by R. M. Kleinpell. R, rare; F, few; C, common; A, abundant; cf., not certainly identified but resembles the species listed] 

Species 

Buliminella brevior Cushman...... __ . ______ ...... 

Buliminaovatad'Orbigny?-... __ . _ . __ .... __ .... 

Bolivina advena var. ornata Cushman (including Boliv- 

Bolivina advena var. striatella Cushman........ _ . __ . 

Bolivina floridana Cushman...... _ __ . ________ . 

Uvigerinella californica var. ornata Cushman. ..-.--.-.... 

Uvigerinella californica var. parva Kleinpell (Uvigerinella 

cf. U. californica Cushman) .. . __ ...... __ ....... 

Siphogenerina collomi Cushman _ . ........... _ ........ 

Siphogenerina nuciformis Kleinpell (Siphogenerina aff. 

Valvulineria californica var. appressa Cushman-. -------- 

Valvulineria miocenica Cushman? _ . __ ........... 

Valvulineria depressa Cushman..... _ .................. 

Valvulineria ornata Cushman (including Valvulineria? 

Pulvlnulmella subperuviana Cushman? (Pulvinulinella? 

Cassidulina panzana Kleinpell (Cassidulina aff. C. crassa 

d'Orbigny) __ ...-..--.......-...-..-... .. .. 

Cassidulina williami Kleinpell (Cassidulina cf. C. sub- 

globosaH. B. Brady). ................................. 

Pullenia miocenica Kleinpell (Pullenia aff. P. sphaeroides 

Pullenia miocenica var. globula Kleinpell (Pullenia aff. 

Planulinacf. P. arimincnsis d'Orbigny. ....... _ ........ 

' Apparently same as locality 3. 

2 Apparently same as locality 7. 

Siphogenerina reedi 

zone (?) 

shale in Reliz Canyon in Monterey County, 46 with, the 

fauna from Santa Clara County described by Chap 

man, 47 and with the fauna of the Claremont shale in 

the Monterey group of Contra Costa County. 48 

Locality 11 represents the S. nuciformis zone (zone C 

of preliminary paper), which overlies the S. reedi zone. 

The S. nuciformis zone is particularly well developed 

in the Monterey on Chico Martinez Creek, on the west 

side of San Joaquin Valley, where it is known locally as 

" the Valvulineria flood zone." 49 The assemblages from 

localities 7, 10, and 12b are suggestive of the S. nuci 

formis zone rather than the S. reedi zone. A sample 

that appears to 'be a duplicate of that from locality 7 

contains a Siphogenerina that may be S. nuciformis. 

Locality 12 represents a still higher zone, the S. 

collomi zone (zone D of preliminary paper). The as 

semblage from locality 12 may be correlated with that 

from the frequently cited locality in the lower part of 

the Monterey shale in the type region near Monterey, 

« Kleinpell, R. M., Miocene Stratigraphy of California, p. 125, Am. Assoc. Petro 

leum Geologists, Tulsa, Okla., 1938. 

«' Chapman, Frederick, Foraminifera from the Tertiary of California: California 

Acad. Sci. Proc., 3d ser., vol. 1, pp. 241-260, pis. 29, 30,1900. 

« Kleinpell, R. M., op. cit., p. 56. 

is in the upper part of the sandstone overlying the schist 

basement. Most of the specimens are in the form of 

molds and impressions, some of which yield satisfac 

tory guttaperciia squeezes. A few similarly preserved 

Gastropods: 


species were found at a nearby locality (locality 13a), 

also near the top of sandstone resting on schist. 

The species collected from the middle part of the 

Altamira shale are given in the following table: 

Mollusks from middle part of Altamira shale member of Monterey shale 

[Identifications by W. P. Woodring. E, rare; F, few; C, common; A, abundant; cf., not certainly identified but resembles the species listed] 

Diodora aff. D . aspera ("Eschscholtz" Rathke) ....:.....--.--------.-----.-.-.-. 

Homalopoma? sp.. ........ ______ . _____ . _ , . __ ...-....--.... __ ... 

\ Stronibnscf. S. gatunonsis Toula(pl. 28, flgs. 3, 4)..... .......'......... .... . ... ... 

Ncvorita? of. N. rcclusiana (Deshayes) (small specimens) (Neverita cf. N. reclusiaj 

"Phos" dumblcanus Anderson (Tritiaria (Antillophos) dumblei (Anderson)) (pi. 28, flgs. 5. 6)...........-....,............... 

"Miurox" cf. "M." wilkesanus (Anderson) ("Murithais" wilkesanus (Anderson)?) 

Tritonalla?sp._ _ ..... _ . _ . ___ ............ __ . _____ . ___ . ......... 

Mitrolla cf. M. tubcrosa (Carpenter).... ______ ... __ ... _ ....... ___ ... 

Kncfastia cf. K. funiculata (Valenciennes) (pi. 28, flg. 13) ...................... 

Crassispira sp. (cf. undescribed species from Gulf of California in U. S. Nat. Mus. ) ... ... ... 1 ... - ................. _.... 

"Clavatula" cf". "C." iablata Gabb (pi. 28, ~fig.~9).. _ ............................. 

Torebra (Paratorobra) cf. T. (P.) lepta Woodring..... ___ . _ ..... ___ . .... 

Conns cf. C. forgusoni Sowerby (small specimen) _ .......'.... ---__.__- __ ... 

ficaphopod: 

Pelocypocls: 

Tellina cf. T. idae Dall. ........................................................... 

Tolllnacf. T. rcclusa Dall. ....-..-.-..........-.-.-.... ..--..-----...-.......-.. 

Macrocallista cf. M. maculnta (LinnC) (pi. 28, flg. 19) _ . __ .... _ . _ . ___ . ... 

Chiono cf. C. succincta (Valenciennes) 

Chionc (Lirophora) aft. C. mariae (d'Orbigny) (Chione (Lirophora) aff. C. latilaminosa Anderson and Martin, (pi. 28, flg. 23). . 

Oallitliaca? cf. 0. staminoa (Conrad) . . ... .... 

Trigoniocardia all. T. antillarum (d'Orbigny) (Trigoniocardia cf. T. haitensis (So sverby)) (pi. 28, figs. 24, 25)--..-...-....... 

1 .Impression of largo carlnate specimen. Not collected. 

3 Names in parentheses were used in preliminary paper (Am. Assoc. Petroleum Geologists Bull., vol. 20, No. 2, pp. 125-149,1930). 

Though the material from localities 13 and 13a is 

poorly preserved, it represents an essentially new fauna 

.for the Coast Ranges. Strombus (pi. 28, figs. 3, 4), 

Costoanachis (pi. 28, fig. 7), Knefastia (pi. 28, fig. 13), 

''Clavatula," (pi. 28, fig. 9), Paratereba in the restricted 

sense, Crassinella (pi. 28, fig. 12), Divaricella (pi. 28, 

figs. 17, 20, 21), and Trigoniocardia (pi. 28, figs. 24, 25) 

have not been recorded from the Miocene of coastal 

California and the San Joaquin Valley; "Phos" (pi. 28, 

figs. 5, 6) and Lirophora (pi. 28, fig. 23) have not been 

found heretofore in the Coast Ranges. The three 

following factors may have a bearing on the composi 

tion of this fauna location, horizon, and preservation 

of small species. (1) The genera and subgenera con 

stituting new i-Qcords are tropical migrants that may 

not have ranged much farther northward during 

Miocene time. (2) According to the stratigraphic 

position of the fossiliferous sandstone with reference 

592787 45 3 

13 

R 

F 

R 

A 

C 

F 

R 

F 

R 

F 

A 

C 

F 

R 

F 

R 

R 

C 

C 

R 

F 

F 

A 

R 

A 

C 

- R 

R 

R 

A 

F 

R 

F 

A 

R 

C 

R 

C 

A 

A 

C 

13a 

Ri 

(?) 

R 

R 

R 

R 

(?) 

F 

Localities 

2b 

(?) sp. 

to the Miraleste tuff, the fauna is evidently approxi 

mately in the Siphogenerina reedi zone; that is, near 

the base of the Valvulineria californica zone in the 

restricted sense. The fossiliferous sandstone may be 

older than the S. reedi zone, as it may represent long- 

continued deposition on a schist ridge. The field 

relations suggest, however, that the sandstone is 

as young as the S. reedi zone. Mollusk faunas of 

comparable size have not been found elsewhere in 

California in the .approximate position of the S. reedi 

zone. In the Coast Ranges strata in that part of the 

Miocene section consist generally of fine-grained rocks 

in which mollusks are absent. (3) Small species of 

mollusks are generally rare in the California Miocene. 

"Phos" and Lirophora are .recorded from the Bakers- 

field region on the east side of the San Joaquin Valley 

but not from other localities. 

R 

12a 

cf.


Turritella ocoyana (pi. 28, figs. 1, 2), "Nassa" aff. 

"N.'\ arnoldi, "Phos" dumbleanus (pi. 28, figs. 5, 6), 

Cancellaria cf. C. condoni (pi. 28, fig. 8), Conus oweni- 

anus (pi. 28, figs. 14, 15), and Aeguipecten andersonit 

suggest the Temblor fauna as that term is generally 

used. According to Kleinpell's interpretation of the 

succession of foraminiferal zones, the fauna from the 

Palos Verdes Hills is younger than the Barker's Ranch 

fauna 52 in the Bakersfield region a fauna that has a 

comparable proportion of small species and is considered 

characteristic of the Temblor. Mollusks from the 

Topanga formation in the Santa Monica Mountains M 

and from strata assigned to the Temblor along the coast 

southeast of the Palos Verdes Hills 54 consist principally 

of large species. Foraminif era from the lower part of the 

Topanga formation are assigned by Kleinpell to the 

Siphogenerina branneri zone, which is identified in the 

lower part of the Altamira shale. The upper part of the 

Topanga formation may, however, include deposits of 

the same age as the middle part of the Altamira. The 

fauna of the Oursan sandstone and Hambre sandstone 

of the Mpnterey group in the San Francisco Bay region 

also consists principally of large species. 55 These sand 

stone formations in the Monterey group are referred by 

Kleinpell to horizons higher than the middle part of the 

Altamira shale. 

Strombus and Divaricella are found in the Imperial 

formation of the Colorado Desert. 56 The Imperial 

fauna includes species that are more similar to Carib 

bean Miocene fossils than to fossil or riving species from 

the Pacific coast. The following species from the 

Palos Verdes Hills appear also to show that relation: 

Strombus cf. S. gatunensis (pi. 28, figs. 3, 4), "Clavatula" 

d."C." labiata (pi. 28, fig. 9), Terebra cf. T. lepta, Terebra 

cf. T. wolfgangi, Macrocallista cf. M. maculata\(pl. 28, fig. 

19), and Trigoniocardia aff. T. antillarum (pi. 28, figs. 24, 

25). 57 The preservation of some of these species is so 

poor, however, that their affinities are not certain. 

The similarity between the Imperial fauna and the 

fauna from the Palos Verdes Hills may have no age 

significance, as it may be the result of derivation from 

the same source. The Imperial formation isQconsidered 

of Miocene age by some paleontologists and of Pliocene 

age by others. 58 

UPPER PART, 

The upper part of the Altamira shale is characterized 

generally by abundance of phosphatic shale, the phos 

phate material forming thin light-colored or brownish 

layers or nodules. In many areas, particularly in the 

western part of the hills, brown bituminous shale is in- 

" The Barker's Eanch species have been described or recorded in the following 

publications: Anderson, F. M., A stratigraphic study in the Mount Diablo Range of 

California: California Acad. Sci. Proc., 3d ser., vol. 2, pp. 187-188, 195-206, pis. 14-16, 

1905; The Neocene deposits of Kein River, Calif., and the Temblor Basin: Idem, 

4th ser., vol. 3, pp. 99-100, 1911. Anderson, F. M., and Martin, Bruce, Neocene 

record in the Temblor Basin, Calif., and Neocene deposits of the San Juan district, 

San Luis Obispo County: Idem, 4th ser., vol. 4, pp. 41-44, 52-96, pis. 1-8,1914. 

« Arnold, Ralph, New and characteristic species of fossil mollusks from the oil- 

bearing Tertiary formations of southern California: TJ. S. Nat. Mus. Proc., vol. 32, 

pp. 525-526, 528-534, pis. 40^6,1907. Arnold, Ralph, in Eldridge, Q. H., and Arnold, 

Ralph, The Santa Clara Valley, Puente Hills, and Los Angeles oil districts, southern 

California: U. S. Geol. Survey Bull. 309, pp. 147-148, pis. 27-33,1907. Kew, W. S. W., 

Geology and oil resources of a part of Los Angeles and Ventura Counties, Calif.: 

U. S. Geol. Survey Bull. 753, pp. 50-51, 1924. Woodring, W. P., in Hoots, H. W., 

Geology of the eastern part of the Santa Monica Mountains, Los Angeles County, 

Calif.; U. S. Geol. Survey Prof. Paper 165, pp. 100-101,1931. 

«> Woodford, A. O., The San Onofre breccia: California Univ., Dept. Geol. Sci., 

Buil., vol. 15, p. 208, 1925. 

" Merriam. J. C., in Lawson, A. C., U. S. Qeol. Survey Geol. Atlas, San Francisco 

folio (No. 193), p. 11, 1914. 

« Hanna, G. D., Paleontology of Coyote Mountain, Imperial County, Calif.: 

California Acad. Sci. Proc., 4th ser., vol. 14, pp. 454-455, 464-465, pis. 20, 26, 1926. 

" Macrocallista maculata has a range from Miocene to Recent in the Caribbean 

region. Trigoniocardia antillarum is a Recent Caribbean species, the Caribbean 

Miocene allies- of which have been overnamed. 

M Woodring, W. P., Lower Pliocene mollusks and echinoids from the Los Angeles 

Basin, Calif., and their inferred environment: U. S. Geol. Survey Prof. Paper 190, 

pp. 46-47,1938. 

terbedded with the phosphatic shale. Phosphatic 

shale is a minor constituent of the middle part of the 

Altamira, and the Valmonte diatomite member in 

cludes locally thin layers of phosphatic material. 

In the western half of the hills the top of the upper 

division of the Altamira corresponds approximately to 

the transition from hard cherty to soft diatomaceous 

rocks. On the northeast and east slopes the upper 

division includes, however, diatomaceous strata that 

contain blue-schist debris and that are interbedded with 

fine-grained blue-schist sandstone and phosphatic 

shale. In the Whites Point area cherty shale is more 

abundant than elsewhere. 

A peculiar litholpgic facies, consisting of thick blue- 

schist conglomeratic sandstone and brecciated shale, is 

represented in the Point Fermin area. In that area the 

thickness and grain size of the sandstone decrease north 

ward. The thin layers of fine-grained blue-schist sand 

stone and the diatomaceous silt containing schist debris 

farther north are thought to be the equivalent of the 

coarse-grained sandstone of the Point Fermin area. 

The schist debris was derived. evidently from a schist 

area farther south, now covered by the ocean, as was 

inferred for the San Onofre breccia, a Miocene formation 

in the coastal district southeast of the Palos Verdes 

Hills. 59 

Natural exposures of the soft shale constituting a 

large part of the upper division of the Altamira in most 

areas are found only along the sea cliff and in some of 

the deep canyons. The best exposures are in the 

Lunada Bay and Malaga Cove areas, in the cliffs near 

the head of Altamira Canyon and its tributaries, and at 

Point Fermin. The thickness appears to be as much as 

300 feet, possibly even as much as 400 feet, in the 

Malaga Cove area and 250 feet in the Lunada Bay area. 

In a tributary of the middle fork of Altamira Canyon 

the thickness is 185 feet, and in the east fork of Altamira 

Canyon, 1,500 feet to the southeast, it diminishes to 95 

feet. In the Point Fermin area the thickness is at least 

300 feet, and the top is not exposed. In that area, 

however, sandstone forms two thick units. 

Foraminifera assigned to the Bolivina, modeloensis 

zone and the overlying Bulimina uvigerinaformis zone 

were found in strata referred to the upper part of the 

Altamira. 

Strata assigned to the upper part of the Altamira 

shale are exposed in the sea cliff southwest of the Malaga 

Cove beach clubhouse, near the mouth of Malaga 

Canyon. They consist of phosphatic shale with which 

cherty shale and limestone are interbedded. The pro 

portion of cherty shale and limestone decreases upward 

in the section. The lithology in this area is shown in 

the following sections (column 1, pi. 3). The excep 

tionally great thickness suggests some duplication in the 

two sections; however, the thickness is at least 270 feet 

and may be as much as 400 feet, the combined thickness 

of the two sections. If the opal concretions in the 

underlying middle part of the Altamira are at the same 

horizon as in the Altamira Canyon area (columns 2, 3, 

pi. 3), the base .of the v upper part of the Altamira is 

drawn at essentially the same horizon in the two areas. 

" Woodford, A. O., The San Onofre breccia: California Univ., Dept. Geol. Sci. 

Bull., vol. 15, p. 140, 1925.

Section of upper part of Altamira shale member of Monterey shale 

in sea cliff southwest of mouth of Malaga Canyon 

30. 

29. 

28. 

27. 

26. 

25. 

24. 

23. 

22. 

21. 

20. 

19. 

18. 

17. 

16. 

15. 

14. 

13. 

12. 

11. 

10. 

9. 

8. 

7. 

6. 

Phosphatic shale and thin zones of cherty shale. 

Overlain 60 feet southwest of beach clubhouse 

by laminated diatomaceous and phpsphatic 

shale mapped as base of Valmonte dlatomite 

member of Monterey 'shale.___'________'_______ 

Limestone..--________________________________ 

Unexposed, except occasional beds of limestone 

and cherty sliale. Evidently mostly soft shale 

Phosphatic shale and a few thin zones of cherty 

shale. _-------_- __---_-_------------------- 

Limestone.......'...............-.-.-.-.'...... 

Phosphatic shale and a few thin zones of cherty 

shale, especially in lower part___-------------- 

Brecciated limestone. - ....................^..... 

Phosphatic shale and cherty shale.__--______-___ 

Limestone._..........................1....... 

Phosphatic shale. . _____ _______-_--_------__--_ 

Limestone... --------------------------------- 

Unexposed, except few beds of phosphatic shale and 

limestone.___________________-__-_-------__ 

Phosphatic shale. ----------------------------- 

Limestone..._____-----_-__------------------_ 

Phosphatic shale._ ---------------------------- 

Limestone........................ r........... 

Phosphatic shale.____----_------------------_-- 

Limestone_ _'__...._._-____---.-..----._-.--_ 

Phosphatic and cherty shale.------------------- 

Limestone....---__----._--__----_-----------_ 

Phosphatic shale___-_-__----__---------------- 

Limestone... --------------------------------- 

Poorly exposed phosphatic shale.___--------__-_ 

Limestone.-.._-_____------_-_-_----:_---_--__ 

Phosphatic shale containing crushed and leached 

Foraminifera. Thin zones of cherty shale near 

top _._.._._._....._._........___.__._1 

Limestone_.---._--_--.------_-----_---_--_. 

Phosphatic and calcareous shale încluding thin 

zones of cherty shale----_-_--------_----__-_ 

Limestone_ ____-_-__.-----_--.---_-__--____. 

Unexposed____-_---_---------_---_-____---___ 

Limestone....___..--------___________________ 


Ft. in. 

9 0 

2 6 

46 0 

Thickness of section......-.____._...__.._-.. 272 2 

The following section is a continuation of the preced 

ing section southwestward along the sea cliff. There 

is some evidence of faulting, however, at the locality 

where the sections join. 

Section of upper part of Altamira shale member o ] Monterey shale 

in sea cliff immediately southwest of preceding section 

28. Phosphatic shale.__-_--.-__.--_--__-_---_--.__ 

27. Limestone..__________________________________ 

26. Phosphatic shale__--------_-------_------_---_ 

25. Limestone.__________-_-___---_'--__-_-_-______ 

24. Phosphatic shale and thin zones of .cherty shale. __ 

23. Limestone.............................1...... 

22. Cherty shale, calcareous phosphatic shale, and 

limestone. A 5-inch layer of sandy bentonitic 

tuff 10 inches*from top_____----__---------_-- 

21. Limestone_-_-_---_------_--___---------_-__ 

20. Cherty and calcareous shale._---_____----___-_- 

19. Limestone__.---_--------_--------------_--- 

18. Cherty and calcareous shale..------------------ 

17. Limestone__________________________________ 

16. Cherty shale, calcareous shale, phosphatic shale, 

and limestone____-_-_---------_-_-----_.-- 

15. Limestone .-._-__--------.----_-_------_--__ 

14. Limestone, calcareous shale, phosphatic shale, and 

cherty shale__-_--_-______-----_-----_--_-_- 

13. Limestone.-.__-___-_----______-_----__.___-__ 

12. Laminated chert.____.______._____.-_-___.____ 

11. Thin-bedded limestone_____---_-----_---__.__. 

10. Phosphatic and cherty shale.-----_--------__-__ 

9. Concealed by retaining wall at pier,_____________ 

8. Phosphatic and cherty shale._-----__----------. 

7. Limestone..._________________________________ 

6. Phosphatic and cherty shale.------------------- 

5. Limestone.__________________________ _________ 

4. Phosphatic shale..----.----------------------- 

22 1 

35 2 

15141 

30 

151 

15 3 

181121141 

7 1 

4 

2 

18 3 

Ft. in. 

3 6 

1 ' 4 

2 6 

1 6 

10 15352 

11 1 

8 0 

1 0 

10 

10 

4 6 

33 0 

9 0 

1 10 

5 0 

5 10 

3 6 

Section of upper part of Altamira shale member of Monterey shale 

in sea cliff immediately southwest of preceding section Continued 

Ft. in. 

3. Calcareous, phosphatic, and cherty shale.-..----- 2 6 

2. Limestone..-.---__-____------------_--------- 2 0 

1. Phosphatic shale. Underlain by strata assigned to 

middle part of Altamira shale. For downward 

continuation of section see p. 20_____________ 5 6 

Thickness of section.---__._-__.._-._____.- 139 2 

Phosphatic shale is exposed in road cuts on the 

flanks of the syncline on the upper slope of the hills in 

the southeastern part of the Malaga Cove residential" 

district inland from Bluff Cove. 

IUNADA BAY AREA 

Bituminous and phosphatic shale crop out along 

Lunada Bay on the soilth limb of the syncline emerging 

on the coast on the south side of Palos Verdes Point 

(pi. 8). The fresh bituminous shale is dark brown; 

weathered surfaces are light buff-gray. The phosphatic 

layers are grayish-brown on unweathered surfaces and 

greenish yellow on weathered surfaces. The shale in the 

sea cliff at Lunada Bay, north of the mouth of Agua 

Amarga Canyon, is reddish and black, owing to com 

bustion of organic -matter in the bituminous shale. A 

section that includes strata in the middle and upper 

parts of the Altamira, as exposed in Agua Amarga 

Canyon at the head of Lunada Bay, is as follows: 

Section of upper and middle parts of Altamira shale member of 

Monterey shale in Agua Amarga Canyon at head of Lunada Bay 

Upper part: 

41. Limestone-.-_____________________________ 

40. Bituminous phosphatic shale, weathering like 

unit 35. A few. thin beds of harder shale. _ _ 

39. Concretionary limestone containing pieces of 

large bones, presumably cetacean remains _. 

38. Bituminous phosphatic shale, .weathering like 

unit 35, and zones 2 to 3 inches thick of 

harder somewhat porcelaneous shale. _____ 

37. Platy limestone and calcareous siltstone--.-__ 

36. JPprcelaneous shale__-- - ------------------ 

35. Bituminous phosphatic shale. Main part of 

shale weathers light buff gray; phosphatic 

layers weather greenish yellow.----------- 

34. Blocky-weathering limestone.____--_-______. 

33. Tuffaceous (?) sandstone stained greenish.... 

32. Mostly porcelaneous shale______.__-_.-___ 

31. Poorly exposed siltstone, bituminous shale, 

30. 

29. 

and harder porcelaneous shale.___________ 

Fresh brown bituminous phosphatic shale, 

somewhat porcelaneous-_________________ 

Chert lens._______________________________ 

28. Fine-grained calcareous (?) sandstone; includes 

3-inch chert lens.___.---_____________ __. 

27. Fissile brown bituminous phosphatic shale.... 

26. Siltstone and fine-grained calcareous (?) sand 

stone ____.._____--__________-_____-___- 

25: . Platy somewhat porcelaneous brown shale.... 

24. Brown bituminous shale containing a few 

phosphatic nodules.___-______'___________ 

23. Limestone._ ______________________________ 

22. Brown bituminous shale. Lower foot somewhat 

harder than remainder._____________ 

21. Limestone._______________________________ 

20. Brown bituminous phophatic shale.--------- 

19. Limy siltstone and limestone. Includes a 

half-inch bentonitic (?) clay.__-_-_____-.. 

18. Brown bituminous phosphatic shale containing 

leached Foraminifera.________________ 

Middle part: 

17. Laminated silty limestone.___________^___.. 

16. Fissile, somewhat porcelaneous shale containing 

phosphatic nodules.__._.. ...........L 

15. Alternating porcelaneous and softer shale___ 

14. Porcelaneous shale______________________ 

Ft. in. 

1 5 

10 0 

1 10 

2-4 

10 

2 3 

1 1 

4 1 

2 1 

16 

2 

12 

2 

3 

6 1


Section of upper and middle parts of Altamira shale member of 

Monterey shale in Agua Amarga Canyon at' head of Lunada 

Bay Continued 

Middle part Continued. A. in. 

13. Fissile, somewhat porcelaneous shale___--____ 5 

12. Porcelaneous shale.___-_----------___-_-_. 2 2 

11. Fissile, somewhat porcelaneous shale___-_-__- 1 3 

10.- Hard cherty shale._______________ _______ 9 

9. Calcareous siltstone---------------.-.------- 1 2 

8. Hard cherty shale._________________1______ 1 11 

7. Brown somewhat porcelaneous shale____-_-__ 11 

6. Hard cherty shale in layers 1 to 3 inches thick 

alternating with softer shale in layers Yz to 1 

inch thick__---___-________-________-___ , 5 8 

5. Soft, somewhat porcelaneous shale_._____-_-_- 3 1 

4. Brown phosphatic shale.____________________ 7 

3. Tuffaceous (?) sandstone.------------------ 3 

2. Dark brown shale containing phosphatic 

stringers ____--_--_-_---__----__---.---- 2 11 

1. Calcareous siltstone. Base not exposed------ 2 8 

Thickness of section__-_____-_---_------- 135 2 

A thickness of approximately 100 feet in the fore 

going section is assigned to the upper part of the Alta 

mira shale. The uppermost part of this division is 

exposed in the trough of the syncline on the south side 

of Palos Verdes Point under a thin cover of the over 

lying Valmonte diatomite member, where the section 

given below was measured. This section and that 

measured on Agua Amarga Canyon could not be cer 

tainly tied together, owing to a possible fault in the 

area of burnt shale immediately to the left of the 

relatively steeply dipping strata shown on plate 8. If 

there is no significant break in that area, the base of 

the Palos Verdes Point gection is estimated to be about 

150 feet above unit 34 of the Agua Amarga Canyon 

section, making a total estimated thickness of about 

250 feet for the upper part of the Altamira. 

Section of upper pait of Altamira shale member and Valmonte 

diatomite member of Monterey shale in sea cliff on south side 

of Palos Verdes Point 

Valmonte diatomite member: _ Ft. in. 

16. Diatomaceous and phosphatic shale. Thick 

ness estimated. ____________--_____-__-.,_ 10 0 

15. Phosphatic shale. Thickness estimated-__-__ 10 0 

14. Lens of diatomaceous shale-.----.-/-----.-- 6 

13. Silty phosphatic shale.___________________ 6 6 

12. Diatomaceous and phosphatic shale.________ 3 2 

Upper, part of Altamira shale member: 

11. Phosphatic shale stained greenish yellow and 

thin zones of harder shale________________ 6 7 

10. Porcelaneous shale ________________________ 6 

9. Limestone__________________--_-_____---_ 1 0 

8. Phosphatic shale__._______________________ 11, 

7. Porcelaneous shale and thin zones of softer 

bituminous shale--_-_--_s.__-____-_---___ 3 5 

6. Phosphatic shale________-___--___--_---_-_ 10 

5. Limestone--.---..---_____________________ 1 3 

4. Porcelaneous shale and thin zones of softer 

bituminous shale._______ ______..__-____ 4 9 

3. Bituminous shale, including a 2-inch layer of 

harder shale_____________________________ 2 8 

2. Porcelaneous shale. ____--_----_---__------ 1 11 

1. Limestone- 

Thickness of section.__-_-_--__-___--_-__ 57 6 

Bituminous shale and phosphatic shale, locally burnt, 

are exposed in highway cuts in the synclinal area in 

the eastern part of the Margate residential area inland 

from Lunada Bay. 

CREST OF HILLS 

Phosphatic shale, including toward the top thin 

laminae of diatomaceous shale, underlies the flanks of 

the broad, shallow syncline along the crest of the hills, 

but is well exposed only in the cliffs near the head of 

Altamira Canyon and its tributaries and in highway 

cuts. In the following section, measured in a tributary 

of the middle fork of Altamira Canyon (third canyon 

from right in background, pi. 4), strata assigned to 

the upper part of the Altamira have a thickness of 

about 185 feet (column 2, pi. 3). 

Section of Monterey shale, including upper part of Altamira shale 

member, in tributary of middle fork of Altamira Canyon 

Valmonte diatomite member: 

58. Limestone____---__-----------_---_-_..___ 

* 57. White silty shale______-__-._. _____________ 

56. Bentonitic clay. ____---_-__-_-_-__________ 

55. Diatomaceous shale. ______________________ 

54. Laminated cherty and porcelaneous shale. ___ 

53. .Diatpmite.------. ---------------.-__.____ 

.52. Laminated chert.---.-.--... _.-_-._.______ 

51. White silty shale.----,---------.. -.__-._... 

50. Limestone.... ------ ______________________ 

49. Diatomaceous shale and diatomite..__ _______ 

48. Laminated cherty and diatomaceous shale____ 

47. Diatomaceous shale and diatomite_____ ______ 

46. Laminated chert_ ___-_----__--__-___.__.__ 

45. Diatomaceous shale. ____---------._.--._.. 

44. Laminated chert. _ __-_----__.-.--_________ 

43. White silty shale, thin laminae diatomaceous-- 

42. Porcelaneous shale. ________________________ 

41. White silty shale. _________________________ 

40. Limestone mapped as base of Valmonte diato- 

rnite. __ ________________________________ 

Altamira shale member: 

Upper part: 

39. Phosphatic shale and diatomaceous shale 

in thin laminae. ____________________ 

38. Poorly exposed brown phosphatic shale; 

a few diatoms in some layers. ________ 

37. Limestone----------------------.---.. 

36. Poorly exposed brown phosphatic shale... 

35. Limestone.... ---_-__- _______________ 

34. Brown phosphatic shale, lower part poorly 

exposed-- .----_-- --.----.---.--...I 

33. Limestone _ ____-___l____-____________ 

32. Poorly exposed brown phosphatic shale 

and thin laminae of white diatomaceous 

shale. Laminae of diatomaceous shale 

more abundant than in unit 30, gradu 

ally less abundant upward- ___- _______ 

31. Limestone.--------------------------. 

30. Poorly exposed brown phosphatic shale 

and thin white laminae of diatomaceous 

shale, some layers of .which consist 

mostly of Thalassiothrix.. _________'____ 

29. Brown phosphatic shale and thin zones of 

porcelaneous shale___--------_-___.__ 

28. Limestone _ _________________________ 

27. Brown phosphatic shale including 7 zones 

of porcelaneous shale 1 to 3 inches thick. 

26. Limestone-... --_------.--------_---.- 

25. Unexposed. __--------__.-----_--.---- 

24. Brown phosphatic shale; a few thin zones 

of porcelaneous shale in lower half _____ 

23. Limestone.^.. _-__------_--------.--.- 

22. Unexposed- __---_-----_--_-----___-__ 

21. Brown bituminous -shale and thin zones of 

porcelaneous shale_____-______ _______ 

20. Brown bituminous shale, a few phosphatic 

nodules ______-_-_-____---_____-____ 

19. Dense limestone __ _ __ ________________ 

1 8. Unexposed __________ _________-__l-___ 

1 7. Brown phosphatic shale. _______________ 

16. Limestone. -___-____-___----_._____.-- 

15. Brown phosphatic shale_-__-_______.___ 

14. Limestone containing phosphatic nodules. 

13. Brown bituminous shale containing phosphatic 

nodules. _____________________ 

12. Poorly exposed soft shale and thin zones 

of porcelaneous shale_ ___-__-_-_-__-. 

11. Limestone----____----_--_------_--___ 

10. Brown bituminous shale, lower part con 

taining scattered phosphatic nodules 

and upper part including many thin 

phosphatic layers_-_______.__________ 

ft- 

1 0 

3 

2 

6 

5 6 

10 0 

1-6 

10 

1 6 

3 0 

11 

4 6 3 

3 0 5 

3 0 3 

4 0 

11 

7 6 7 

12 .6 

1 0 

10 8 6 

12 1 

15 2 

20 

2 4 

20 14 

11 

11 1 

3 0 

0 00 

3 10 

11 

6 11

Section of Monlerey shale, including upper part of Altamira shale 

member, in tributary of middle fork of Allamira Canyon Con. 

Altamira shale member Continued. Ft -

32 


chiefly of rather soft porcelaneous shale and silty shale, 

is almost 100 feet thick at the top of the cliff but thins 

south westward down the cliff, evidently through grada 

tion into the sandstone forming the overlying unit. 

The upper sandstone forms the 100-foot sheer cliff 

at the Point (pi. 9) and has approximately that thick 

ness. It consists of blue-schist sandstone, bituminous 

and phosphatic shale, and breccia. The sandstone is 

of coarser grain than that in the lower unit and contains 

pieces of schist generally a few inches long but excep 

tionally as much as 7 feet long. The beds of sandstone 

are as much as 5 to 10 feet thick. Some contain bone 

fragments, one of which was observed to have a brilliant 

blue coat, presumably viyianite. The bituminous and 

phosphatic shale is thin-bedded, and some layers 

contain diatoms. The thickness of the beds of breccia 

ranges from a fraction of a foot to several feet.- Most 

of the beds consist of shale fragments ranging in length 

from a few inches to several feet (pi. 10, B). Layers 

of shale can be traced into breccia composed of shale 

fragments of identical composition and embedded in 

a sandstone matrix like that interbedded with the shale. 

Breccia composed of sandstone or of mixtures of shale 

and sandstone is relatively rare. The breccias were 

formed evidently while the sediments were being 

deposited; that is, they are evidently penecontem- 

poraneous, and the shale and sandstone were consol 

idated enough to form fragments when they were 

ruptured. The rupturing may have been due to 

earthquake jars and submarine sliding. The entire 

upper sandstone has other curious depositional features. 

At the base of many of the beds of sandstone is a scour 

discontinuity, as may be seen on plate 10, B. Discord 

ant contacts, including truncation of minor folds, are 

common. Isolated fragments of shale occur hi sand 

stone, and sandstone grades laterally into shale. 

On the west side of Point Fermin (pi. 9, A) the shale 

underlying the upper sandstone appears to be thicker 

than on the east side, but much of it is obscured by 

talus. As exposed on the cliff it consists of porce 

laneous and silty shale underlain by silty shale, phos 

phatic shale, and thin beds of fine-grained blue-schist 

sandstone. A 3-foot bentonitic tuff is included in the 

shale 15 feet below the irregular contact at the base 

of the upper sandstone. Foraminifera of the Bolivina 

modeloensis zone were found in silty shale at the foot 

of the cliff about 65 feet stratigraphically below the 

base of the upper sandstone (locality 16). 

-Half a mile to a mile northwest of Point Fermin 

blue-schist sandstone including a few beds of brecciated 

shale is exposed along the sea cliff. This sandstone 

corresponds apparently to the lower sandstone on the 

east side of Point Fermin. The mineralogy of a sample 

of sandstone from this area was described by Wood- 

ford. 61 Silty shale at the top of the cliff, along the 

road leading to Whites Point, contains Foraminifera 

of the Bolivina modeloensis zone (locality 14). This 

shale appears to overlie the sandstone just mentioned. 

The upper and middle parts of the Altamira are not 

satisfactorily differentiated in the area inland from 

Whites Point. Silty shale interbedded with cherty 

shale at locality 15 contains Foraminifera assigned 

doubtfully to the Bolivina modeloensis zone. Phos 

phatic shale was not observed in this region. 

FOSSILS 

FORAMINIFERA 

Identifiable Foraminifera were found in the upper 

part of the Altamira shale only at localities near Point 

Fermin and Whites Point. Leached and crushed 

Foraminifera were observed in the more typical phos 

phatic and bituminous shale of other areas. The 

material collected is assigned by Kleinpell to his 

Mohnian stage, the base of which corresponds to the 

base of the upper Miocene according to current Coast 

Range usage. The faunas from localities 14 and 16, 

and doubtfully from locality 15, are referred to the' 

Bolivina modeloensis zone (zone E of preliminary 

paper) 62 and that from locality 17 to the overlying 

Bulimina uvigerinaformis zone (zone F of preliminary 

paper). Locality 17 is close to the top of the Altamira 

shale according to the stratigraphic classification 

adopted. 

The following species were identified by Kleinpell: 

81 Woodford, A. O., The San Onofre breccia: California Univ., Dept. Qeol. Sci.. 

Bull., vol. 15, p. 210, 1925. 


Petroleum Geologists Bull., vol. 20), pp. 125-149. 

Foraminifera'from upper part of Altamira shale member of Monterey shale 

[Identifications by R. M. Kleinpell. R, rare; F, few; C, common; A, abundant] 

Species 

Elphidium granti Kleinpell (Elphidium aff. E. crispum (Linne))(Kleinpell, pi. 1$, figs 1, 11) '.... ..-..-....-...--..-.--..-.. 

Bolivina fioridana Cushman.. _ .................................... -.... ... ... .......................................... 

Seo footnotes at end of table. 


' 15 

F 

R 

R 

R 

F 

C 

14 

(?) 

R 

F 

R 

C 

C 

R 

A 

R 

R 

Localities 

16 

R 

F 

R 

R 

R 

R 

C 

R 

F 

R 

F 

R 

Bulimina 

uvigerina 

formis zone 

17 

R F 

R 

R 

R 

R 

(?) 

C 

R

MIOCENE SERIES 

Foraminifera from upper part of Altamira shale member of Monterey shale Continued 

Species 

Cibicldcs nltftiniraonsis Kleinpell (Cibicidcs sp.) (Kloinpell, pi. 19, figs. 4, 5, 8) '............................-................. 

Clbicicles illingi (Nuttall) (cf.) ---------..--.------------ - - ----- - ------------ 

Localities 


' 15 

C 

F 

14 

F 

R 

C 

A 

C 

R 

A 

F 

R 

R 

R 

R 

R 

16 

R 

R 

F 

R 

R 

F 

R 

R 

F 

R 

R 

33 

Bulimina 

uvigerina- 

formis zone 

1 Zonal position uncertain. 

3 Names in parentheses were used in preliminary paper (Am. Assoc. Petroleum Geologists Bull., vol. 20, No. 2, pp. 125-149,1936). 

KIclnpell, R. M., Miocene stratigraphy of California, Am. Assoc. Petroleum Geologists, Tulsa, Okla., 1938. The citations in the table refer to illustrations of specimens 

from tho Palos Vordcs Hills. 

Kleinpell's comments on the foraminiferal faunas are 

summarized as follows: 

Assemblages from localities 14 and 16 are character 

istic of the Bolivina modeloensis zone, which immediately 

overlies the Siphogenerina collomi zone at several widely 

separated localities in California. Bolivina modeloensis, 

Cassidulina monicana, and Virgulina californiensis var. 

ticensis are restricted to this zone. It is further charac 

terized by the earliest appearance of Uvigerina hootsi, 

Uvigerina segundoensis, Uvigerina subperegrina, and 

Valvulineria araucana. Though a number of species, 

particularly those belonging to the Buliminidae, are 

held over from the preceding Luisian stage, stocks like 

those of Valvulineria californica, Valvulineria miocenica, 

and Siphogenerina, which dominate the Luisian faunas 

and are tropical in their affinities, are lacking in the 

Bolivina modeloensis zone. Faunas very close to those 

from localities 14 and 16 occur in the typical Bolivina 

modeloensis zone at the base of the Modelo formation 

(Monterey shale of some geologists) near Mohn Spring 

in the Santa Monica Mountains °3 and in the Tice shale 

of the Monterey group in Contra Costa County. 64 

The relatively meager collection from locality 15 

lacks stratigraphically diagnostic elements other than 

Virgulina miocenica and Bolivina subhughesi, both of 

which, are known to range from the Bolivina modeloensis 

zone up into the lower part of the Bolivina hughesi zone. 

Field relations indicate that the strata at locality 15 

are not younger than those at localities 14 and 16. 

Locality 17 represents a distinct zone, the Bulimina 

uvigerinaformis zone. Bolivina sinuata var. alisoensis 

and Bulimina uvigerinaformis appear to be character 

istic of that zone. The faunas from the Bulimina 

uvigerinaformis and Bolivina modeloensis zones are 

M Kleinpell, R. M., Miocene stratigraphy of California, p. 129, Am. Assoc. Petro 

leum Geologists, Tulsa, Okla., 1938. 

8< idem. 

closely related, and some paleontologists group them in 

one zonal unit designated the Baggina californica zone. 

Assemblages with which that from locality 17 may be 

correlated are found near the base of the McLure mem 

ber of the Monterey shale along Reef Ridge in the 

Coalinga district, 65 250 feet above the base of the 

Modelo formation near Mohn Spring in the Santa 

Monica Mountains, 66 and at the type locality of the 

Bulimina uvigerinajormis zone east of the mouth of 

Dos Pueblos Canyon, Santa Barbara County. 67 

MOLLUSKS 

Kew found poorly preserved remains of an Aegui- 

pecten, suggestive of A. andersoni, and an oyster in 

sandstone in the Point Fermin area. Fragmentary 

remains from sandstone in the same area were recorded 

by Wood ford 68 as Lyropecten crassicardo? ["Pecten"], 

and Ostrea titan?. An incomplete mold of a large. 

Lyropecten from conglomeratic sandstone in the Fort 

McArthur Upper Reservation is identified as L. cf. 

crassicardo. 

VALMONTE DIATOMITE MEMBER 

The Valmonte diatomite member 69 overlies the 

Altamira shale member. The type region is along 

the lower course of Agua Negra Canyon, southeast of 

the Valmonte residential district, where diatomite îs 

quarried and processed. The Valmonte includes the 

relatively pure diatomaceous strata of the Monterey. 

8» Kleinpell, R. M., in Woodring, W. P., Stewart, Ralph, and Richards, R. W., 

Geology.of the Kettleman Hills oil fields, Calif.; stratigraphy, paleontology, and 

structure; U. S. Geol. Survey Prof. Paper 195, pp. 127-128,1940 [1941]. 

88 Kleinpell, R. M., Miocene stratigraphy of California, p. 129, Am. Assoc. Petro 

leum Geologists, Tulsa. Okla., 1938. 

67 Idem. 

8S Woodford, A. O., op. cit., p. 211. 

8» Woodring, W. P., Bramlette, M. N., and Kleinpell, R. M., op. cit. (Am. Assoc. 

Petroleum Geologists Bull., vol. 20), p. 143. 

17 

C F 

R 

R 

F 

C 

R 

R 

R

34 


Owing to the change from cherty shale and phosphatic 

shale to diatomaceous rocks, the Altamira and Valmonte 

members are well defined in the western part of the 

hills. On the northeast and east slopes differentiation 

of the two members is difficult, as the middle and 

upper parts of the Altamira include diatomaceous 

rocks. In those areas only relatively pure, diatoma 

ceous. strata overlying diatomaceous rocks interbedded 

with cherty shale, blue-schist sandstone, and phosphatic 

shale are now assigned to the Valmonte. 

Diatomite occurs in the Valmonte as; layers or 

laminae of varying thickness. In some areas thinly 

laminated diatomite forms units several feet thick 

alternating with massive diatomaceous mudstone. In 

other ,areas the entire exposed thickness of the Valmonte 

consists of laminated diatomite and diatomaceous 

shale containing varying proportions of diatoms. Some 

of the thick units and also some of the thin laminae 

in areas where thick units are absent consist of a 

feltlike mass of the pelagic hairlike diatom Thalassio- 

thrix. In most of the layers and laminae, however, 

relatively large discoidal diatoms are the most abundant 

constituents noted in field examination. 

N. 

, STRATIGRAPHY AND LITHOLOGY 

MALAGA COVE AREA 

The strongly deformed formations in the sea cliff at 

Malaga Cove include the Valmonte diatomite (pi. 10, 

A; fig. 7). The strata at that locality assigned to the 

Valmonte consist of laminated diatomite and diato 

maceous shale containing exceptionally abundant 

layers, stringers, and elongate nodules of soft phos 

phatic material. A thickness of about 100 feet is. ex 

posed on the north limb of the syncline containing the 

overlying Malaga mudstone member and apparently 

about 200 feet on the south limb. In the faulted areas 

beyond the limb of the syncline stratigraphic relations 

are uncertain. 

The dry diatomite and diatomaceous shale, including 

the phosphatic layers, are white (pi. 11, B}. At the 

base of the cliff, where the rocks are kept wet by waves 

and spray, the diatomite and diatomaceous shale are 

almost black and the phosphatic layers are light gray, 

the two types-of rock being strongly contrasted.. As 

shown on plate 10, C, many phosphatic layers pinch and 

swell, and others are broken into minute displaced 

FIGURE 7. Sea cliff at Malaga Cove, a, Nonmarine terrace cover and dune sand (Pleistocene to Recent); 6, San Pedro (?) sand (Pleistocene); c, Repetto siltstone 

(lower Pliocene); d, Malaga mudstone member of Monterey shale (upper Miocene); e, Valmonte diatomite member, of Monterey shale (upper Miocene). 

At least locally, thin layers of phosphatic material 

are interbedded with laminated diatomite and diatoma 

ceous shale. Perhaps phosphatic material is more 

prevalent than is apparent, for the. thin layers may 

be difficult to recognize in weathered outcrops. Lime 

stone is less abundant than in the Altamira shale. In 

the lower part of the Valmonte of most areas limestone 

occurs in lenticular beds, as in the Altamira. In the 

upper part and in some places throughout the member 

it occurs-as concretions. In laminated rock laminae 

pass generally without interruption into the concre- 

. tions. Locally zones of cherty shale are included in 

the Valmonte, but they are rare. Black chert in the 

form of discontinuous thin layers and stringers parallel 

to the bedding and as veins cutting across the bedding 

is found as a" minor constituent in the Valmonte. 

Vitric volcanic ash in layers a few inches thick, appro 

priately called silver sand by the diatomite quarrymen, 

is another minor constituent. 

The soft rocks of the Valmonte member are exposed 

for the most part only in cliffs and artificial excavations. 

No exposed section of the entire member was found, and 

the thickness is difficult to estimate. The estimate of 

750 feet for the north slope of the hills cited in the pre 

liminary paper 70 may be excessive, owing to inclusion 

of soft shale in the upper part of the Altamira; 500 feet 

is perhaps a better estimate. In San Pedro the 

thickness is only about 250 to 300 feet according to the 

classification now adopted. 

Foraminifera of the Bolivina hughesi zone were found 

in the Valmonte at localities in the San Pedro area. 

70 Woodriug, W. P., Bramlette, M. N., and Kleinpell, R. M., op. cit. 

blocks. The generally consistent relation of offsets 

suggests that the blocks are the result of shearing pro 

duced by differential movement during deformation 

rather than the result of penecontemporaneous breccia- 

tion. Limestone occurs in the form of concretions, 

25 Feet 

NE. 

FIGURE 8. Valmonte diatomite and Altamira shale members of Monterey shale in 

sea cliff near mouth of Malaga Canyon, a, Pleistocene terrace deposits; b, Val 

monte diatomite member of Monterey shale (laminated diatomaceous and .phos 

phatic shale); c, Altamira shale member of Mouterey shale (phosphatic shale, 

limestone, and cherty shale). 

generally laminated, of varying dimensions. The only 

hard siliceous rock observed consists of thin lenticular 

layers, stringers, and veins of black chert. On the 

south limb of the syncline a 4-inch layer of vitric vol 

canic ash is interbedded with diatomacepns shale. 

The base of the Valmonte is exposed in the sea cliff 

200 feet southwest of the mouth of Malaga Canyon. 

The strata are abruptly upturned at that locality, but


A. PORTUGUESE TUFF BED AT TYPE LOCALITY IN KLONDIKE CANYON. 

Light-colored slope in middle of picture is formed by the tuff. Photograph by R. D. Reed. 

B. SCHIST-DEBRIS BRECCIA AT BLUFF COVE. 

Photograph by R. D. Reed. 

ALTAMIRA MEMBER OF MOJfTEREY SHALE AND BASALT. 

C. INTRUSIVE BASALT A QUARTER OF A MILE EAST OF POINT VICENTE. 

The basalt shows as dark rock high on cliff. 

D. CABRILLO FAULT AT CABRILLO BEACH. 

Light-colored cherty and phosphatic shale of upper part of Altamira member oil hanging wall, buff 

siltstone of middle part of Altamira on footwall.


A. TYPE LOCALITY OF MIRALESTE TUFF BED ON \\ l^'l Ml>l ol I I'PER AGUA NEGRA CANYON. 

Arrows point to base of luff. 

B. LOCAL DISCONTINUITY OR BEDDING-PLANE FAULT. 

Foot of sea cliff east of Point Fermin. 

ALTAMIRA MEMBER OF MONTEREY SHALE.

GEOLOGICAL SURVEY PKOFESSIONAL PAPEB 207 PLATE 8 

I'HOSI'HATIC AND BITUMINOUS SHALE IN UPPER PART OF ALTAMIRA MEMBER OF MOiM KliEY SHALE AT LUNADA BAY. 

Note the extensive marine terrace. Photograph by Palos Verdes Estates.


F 

A. WEST SIDE OF POINT 1'ERMIN. 

PROFESSIONAL PAPER 207 PLATE 9 

. . - . ., . B. EAST SIDE OF POINT FERMIN. 

i 

BLUE-SCHIST SANDSTONE IN UPPER PART OF ALTAMIRA MEMBER OF MONTEREY SHALE AT POINT FERMIN.


A. SEA CLIFF SECTION AT MALAGA COVE. 

a, Nonmarine terrace cover and dune sand (Pleistocene to Recent); b, Repetto siltstone (lower Pliocene); c, Malaga mudstone member of Monterey shale (upper Miocene); 

d, Valnionte diatomite member of Monterey shale (upper Miocene). 

'' B. BLUE-SC11IST SANDSTONE AND BRECCIATED SHALE IN UPPER PART OF 

ALTAMIRA MEMBER OF MONTEREY SHALE. 

Highway cut on west side of Point Fermin. 

MIOCENE AND PLIOCENE FORMATIONS. 

C. BROKEN AND STRETCHED PHOSPHATIC LAYERS (LIGHT-COLORED) IN 

LAMINATED DIATOMITE AND DIATOMACEOUS SHALE (DARK-COLORED). 

Valmonte diatomite member of Monterey shale on north limb of southern syncline at Malaga Cove. 

1

-GEOLOGICAL SURVEY PROFKSSIOXAL PAPER 207 PLATE 11 

A. VALMONTE D1ATOMITE MEMBER OF MONTEREY SHALE (b) OVERLAIN BY 

MALAGA MUDSTONE MEMBER (a). 

B. VALMONTE DIATOMITE MEMBER OF MONTEREY SHALE (AT RIGHT) FAULTED 

AGAINST MALAGA MUDSTONE MEMBER (AT LEFT). 

VALMONTE DIATOMITE AND MALAGA MUDSTONE MEMBERS OF MONTEREY SHALE AT MALAGA COVE.

there appears to be no displacement (fig.'8). Dia 

tomaceous laminae were not obeserved in the phos- 

phatic shale at the top of the Altamira, whereas diatoms 

are abundant in the laminated shale assigned to the 

Valmonte. As at the top of the Valmonte in the, 

Malaga Cove section just described, phosphatic layers 

are interbedded with the diatomite and diatomaceous 

shale. 

SYNCLINAL AREAS IN WESTERN PART OF HILLS 

The lowermost part of the Valmonte, representing 

a thickness of 30 to perhaps 75 feet, was identified in 

several synclinal areas in the western part of the hills, 

as shown on the geologic map (pi. 1). It is doubtful, 

however, whether the base of the Valmonte represents 

the same horizon in the different areas. In most of 

these areas thin layers of diatomaceous shale are inter- 

bedded with the phosphatic shale near the top of the 

Altamira. (See sec., p. 30.) 

Sections of the Valmonte as exposed in the sea cliff 

on the south side of Palos Verdes Point and in the cliff 

at the head of a tributary of the middle fork of Altamira 

Canyon, on the south limb .of the syncline along the 

crest of the hills, are included in the sections given on 

page 30. Very little diatomite proper is found in those 

areas. In the area along the crest of the hills a few thin 

zones of laminated chert and laminated cherty shale 

are included in the exposed part of-the Valmonte. 

NORTH SLOPE OF HILLS 

The open cuts and drifts of the Dicalite Co., along 

Agua Negra Canyon and farther east, are located in the 

upper half of the Valmonte. The section exposed in 

the open cuts consists of alternating laminated diatomite 

and massive diatomaceous mudstone, both in units 2 to 

6 feet thick. In one diatomite unit laminae containing 

the hairlike Thalassoihrix were observed throughout the 

entire thickness of 5 to 6 feet. In other units discoidal 

diatoms are abundant, though some laminae contain 

Thalassothrix. Vitric volcanic ash occurs in layers a 

few inches thick. A 4-inch pebble of decomposed schist 

was found at the base of a bed of diatomaceous mud- 

stone. The prevailing dip in this area is northeast; 

however, the strike and the rate of dip change within 

short distances. The relatively great width of outcrop 

is due apparently to these structural irregularities. 

Elsewhere on the north slope of the hills the Valmonte 

is poorly exposed, with the exception .of scattered out 

crops along ravines and highway exposures. 


In the San Pedro area the Valmonte appears to be 

considerably thinner than in the type region. The 

underlying Altamira shale includes much diatomaceous 

silt and diatomaceous shale, some layers of which 

contain so many diatoms that they may be classified 

as diatomite. Only the part of the section that in 

cludes thick units of relatively pure diatomaceous rocks 

is assigned to the Valmonte. The change from the 

underlying Altamira member takes place, however, in 

a transition zone. 

In Peck Park the diatomite, diatomaceous shale, 

and diatomaceous mudstone forming the cliff at the 

north boundary of the park are assigned to the Val 

monte member. Differentiation from the underlying 

Altamira member, which includes much diatomaceous 

material, is, however, not sharp. Thin limestone 

lenses and concretions are included in the Valmonte. 

502787 45 4 


Foraminifera of the Bolivina decurtata subzone were 

found at the foot of the cliff (locality .20). A collection 

from a horizon 20 feet higher stratigraphically is 

assigned to the overlying Bolivina goudkoffi sub'zone 

(locality 20a). At locality 20 a thin layer contains 

impressions and molds of the thin-shelled scallop 

Delectopecten. 

In the first deep ravine east of Peck Park, imme 

diately west of Bandini Avenue, a thickness of 225 

feet of diatomite and diatomaceous mudstone, including 

thin limestone lenses and concretions, is exposed. An 

additional unexposed thickness of 60 feet is estimated 

to underlie the Malaga mudstone member. As the 

lowest exposed strata are near the base of the Val 

monte, the total thickness of that member is not much 

more than 300 feet. Foraminifera of the Bolivina 

goudkoffi subzone were collected at horizons 45, 125, 

and 127 feet above the base of the exposed section 

(localities 21, 2la, 21b, respectively). 

The same lithologic types, representing the upper 

part of the Valmonte, are exposed on the north side of 

San Pedro Canyon, between Meyler and Cabrillo 

Avenues, where Foraminifera of the Bolivina goudkoffi 

subzone were collected (locality 22). Farther south 

the Valmonte is found in street cuts along Alma Ave 

nue between Eighth and Eleventh Streets, on Meyler 

Avenue between Seventh and Nineteenth Streets, and 

on Cabrillo Avenue at Twentieth and Twenty-first 

Streets. On Twentieth Street, 120 feet east of Meyler 

Avenue, diatomite appears^to be faulted against phos 

phatic shale in the upper "part of the Altamira. On 

the geologic map in the preliminary paper 71 a fault 

was continued .southeastward between the Altamira 

and Valmonte members. Even if they are in fault 

contact on Twentietli Street, the displacement is prob 

ably too small to justify that interpretation. 

The transition zone between the Altamira and 

Valmonte members was formerly visible at Cabrillo 

Beach but is now concealed by fill. The Valmonte is 

exposed more or less continuously in the sea cliff from 

a locality immediately south of the drive to Cabrillo 

Beach northward to the. Fort McArthur Lower Reser 

vation. Owing to many minor folds the thickness is 

uncertain. The strata consist chiefly of diatomite, 

diatomaceous shale, diatomaceous mudstone, and thin 

lenses of limestone. Occasional thin layers of volcanic 

ash are impregnated with asphalt. At a point about 

1,000 feet north of the Cabrillo Beach drive a zone 25 

feet thick includes cherty shaie. Foraminifera were 

found in the lower part of the section at locality 18a, 

immediately south of the Cabrillo Beach drive, and at 

localities 18, 19, and 19a, north of the drive. All these 

collections are assigned to the Bolivina decurtata subzone. 

Locality 18 is now concealed by fill. 

FOSSILS 

FORAMINIFERA 

At various localities in the San Pedro area the 

Valmonte diatomite contains well-preserved Foraminif 

era. These collections are assigned by Kleinpell to the 

Bolivina hughesi zone, both the Bolivina decurtata 

subzone (zone G of preliminary paper) 72 and the> over 

lying Bolivina goudkoffi subzone (zone H of preliminary 

paper) being represented. In the San Pedro area the 

Bolivina hughesi zone corresponds approximately to 

» Woodring, W. P.. Bramlette, M. N., and Kleinpell, R. M., op.cit. (Am. Assoc. 

Petroleum Geologists Bull., vol. 20), pp. 128-129, fig. 1. 

« Woodring, W. P., Bramlette, M. N., and Kleinpell, R. M., op. cit., pp. 125-149.

36 


the Valmonte diatomite, for Foraminifera from imme 

diately underlying and overlying strata are assigned 

to other zones. If the section in the deep ravine 

immediately west of Bandini Avenue may be taken as 

a guide, the Bolivina decurtata subzone is thinner than 

Species 

i 

Dentalina cf. D. flliformis (d'Orbigny) (Dentalina sp.) (Kleinpell pi. 22, fig. 1) 2 ___.._ 

Nonioh goudkoffi Kleinpell (Nonion sp.) (Klempell, pi. 20, figs. 2, 5) '. ....... ... ..... 

Buliminella dubia Barbat and Johnson?.--.-.-. _ ........... _ -_..-.---_---.-_-_._ - 

Bulimina inflata Seguenza-.-- ___ .... _ . _ ......... __ ..... _ ................. 

Bulimina montereyana var. delmonteensis Klempell? (Bulimina cf. 'B. affinis d'Or- 

Bulimina ovula var. pedroana Kleinpell (Bulimina afi. B. ovula d'Orbigny). -._-_-.- 

Virgulina californiensis var. grandis Cushman and Kleinpell ___ ......'.............. 

Bolivina bramlettei Kleinpell ("Bolivina beyrichi alata (Seguenza)" Rankin) (Klein 

pell, pi., 21, figs. 9-11) i......................... .................................... 

Bolivina decurtata Cushman (cf.) (Kleinpell, pi. 21, figs. 3, 8) 2 . ................ __ . 

Bolivina girardensis Rankin.- ... _ .......' _ ............... _ ----..--.-.....---.-.- 

Bolivina goudkoffi Rankin- .... _____ ........ __ ..... ___ ... __ .... _ .. _ . 

Bolivina hootsi Rankin __ ...... _ ..........._ ................. __ . ........ 

Bolivina cf. B. interjuncta Cushman... __ .......;.......................... __ .... 

Bolivina malagaensis Kleinpell (Bolivina aff. B. advena Cushman) _ ............... 

Bolivina parva Cushman and Galliher ....... _ .......... _ .... .... 

Bolivina sinuata Galloway and Wissler _ ............................. .. 

Bolivina subhughesi Kleinpell (Bolivina sp.) (Kleinpell, pi. 21, figs. 7, 12) 2________... 

Bolivina subadvena var. spissa Cushman (Bolivina aff. B. subadvena Cushman) 

(Kleinpell, pi. 21* figs. 1, 2, 13) 2... ............. .................... .... 

Bolivina woodringi Kleinpell (Bolivina c.f. B. argentea Cushman) (Kleinpell, pi. 21, 

figs. 4, 5) 2 . -.-.-...---.....-..-... ................................ 

Uvfgerina hannai Kleinpell (Uvigerina aff . U. hootsi Rankin).................. .... 

Uvigerina hootsi Rankin....... _ ..... ............... ... ....... 

Uvigerina modeloensis Cushman and Kleinpell. .................... _ ..... 

Uvigerina segundoensis Cushman and GallUier.... 

Uvigerina cf. U. senticosa Cushman (Kleinpell, ol. 20, fig. 9) 2...... .... 

Uvigerina sp.? (Kleinpell, pi. 20, figs. 1, 17) 2 . ...... 

Uvigerina subperegrina Cushman and Kleinpell- ..-.-..--..-.--... 

Valvulineiiaaraucana (d'Orbigny).. __ ... __ .... __ .... __ . __ . 

Gyroidina soldanii var. rotundimargo R. E. and K. C. Stewart . 

Eponides multicameratus Kleinpell ("Eponides aff. E. broeckiana (Karrer)" Rankin) 

Eponides healdi R. E. and K. C. Stewart. ... . 

Eponides keenani Cushman and Kleinpell.----..-.--.. .. .. ..... 

Baggina californica Cushman... _ 9 .. ... 

Pulvinulinella capitanensis Cushman and Kleinpell?. 

Pulvinulinella sp. (Kleinpell, pi. 20, figs. 3, 4, 7) 8 ..." .. 

Cassidulina delicata Cushman ___ _ ............................ 

Cassidulina barbarana Cushman and Kleinpell..- . ...................... 

Cassidulina crassa d'Orbigny....:.......... . 

Cassidulina modeloensis Rankin. ........ .................. . . 

Chilostomella cf. C. ovoidea Reuss. .......................................... 

Sphacroidina bulloides d'Orbigny. ....!.... ........ 

Globigerina bulloides d' Orbigny _ . ............................ . 

Anomalina hughesi Rankin . ............. 

Planulina cf. P. ariminensis d'Orbigny.................... . 

Planulina depressa d'Orbigny. .......... i. .............................. 

Planulina ornata (d' Orbigny). _.a_ ................................................ 

Discorbinella valmonteensis Kleinpell (Cibicides cf. C. cicatricosa (Schwager) (Klein 

pell, pi. 21, figs. 14-16) i.... ....................................... 

Cibicides illingi (Nuttall) (cf.) (Kleinpell, pi. 20, figs. 18-20) 2 

Foraminifera from Valmonte diatomite member of Monterey shale 

[Identifications by R. M. Kleinpell. R, rare; F, few; C, common; A, abundant] 

the Bolivina goudkoffi, subzone. At that locality 

Foraminifera referred to the Bolivina goudkoffi subzone 

occur 100 feet or less above the base of the Valmonte. 

The species identified by Kleinpell are given in the 

following table: 

18 

R 

R 

R 

R 

R 

R 

R 

A 

5 F 

F 

R 

A 

-F 

R 

R 

F 

C 

R 

CF 

R 

C 

C 

R 

R 

R 

R 

R F 

R 

F 

Bolivina decurtata subzone 

18a 

F 

F 

F 

R 

R 

R 

A 

C 

F 

R 

F 

R 

C 

R 

R 

R 

R 

19 

R 

F 

R 

F 

R 

F 

C 

F 

A 

R 

R 

C F 

R 

R 

F 

A 

F 

(?) 

R 

R 

R 

R 

R 

A 

R 

19a 

R 

R 

F 

R 

R 

R 

R 

A 

R 

F 

R 

R 

F 

F 

F 

F 

F 

R 

R 

R 

R 

R 

R 

Localities 

Bolivina hughesi zone 

20 

R 

R 

R 

F 

R 

. C 

F 

A 

C 

F 

C 

R 

C 

A 

R 

A 

F 

R 

R 

F 

F 

R 

R 

F 

F 

20a 

R 

R 

R 

F 

R 

F. 

R 

F 

R 

R 

R 

A 

R 

A 

R 

F 

F 

C 

F 

R 

Bolivina goudkoffi subzone 

1 Names in parentheses were used in preliminary paper (Am. Assoc. Petroleum Geologists Bull., vol. 20, No. 2, pp. 125-149, 1936). 

2 Kleinpell, R. M., Miocene stratigraphy of California, Am. Assoc. Petroleum Geologists, Tulsa, Okla., 1938. The citations in the table refer to illustrations of specimens 

from the Palos Verdes Hills. 

Kleinpell's comments are summarized as follows: 

The Foraminifera from the Valmonte diatomite rep 

resent the fauna of the typical Bolivina hughesi zone 

21 

R 

F 

R 

A 

F 

F 

F 

' 21a 

F 

C 

C 

R 

F 

C 

F 

C 

A 

F 

F 

R 

A 

R 

21b 

R 

. R 

F 

F . 

C 

F 

F 

A 

C 

F 

R 

R 

C 

22 

R 

R 

R 

F 

R 

A 

R 

v R 

R 

listed by Rankin from Hoots' lithologic units 7 to 16, 

inclusive, in the lower member of the Modelo formation 

(Monterey shale of some geologists) exposed along the 

R 

R 

F 

A 

R 

F- 

R 

A 

R 

R

oad from Girard to Mohn Spring in the Santa Monica 

Mountains. 73 Rankin, Hughes, and GoudkofF4 have 

cited the same fauna from the upper shale member 

of the Puente formation as exposed in La Habra 

Canyon, on .the south flank of the Puente Hills. The 

fauna is represented by rich assemblages of well-pre 

served and characteristic forms in the Palos Verdes 

Hills. Of the species listed by Rankin, Hughes, and 

Goudkoff as characteristic of the zone, only the two 

species of Buliminella are missing in the Palos Verdes 

Hills collections. The fauna from the Valmonte can 

also be correlated with Galliher's middle Nonion 

fauna, 75 which represents the Bolivina hughesi zone in 

the Monterey shale of the type region. 

Two faunal divisions treated tentatively as subzones76 

are recognized in the Valmonte. The differentiation 

is not as clearly defined as the differentiation between 

the zones and is based on quantitative more than on 

qualitative differences. Nevertheless the distinctive 

features of the two subzones persist at a number of 

localities in southern California, including the Girard- 

Mohn Spring section in the Santa'Monica Mountains. 

So far as now known, Baggina californica, Pulvinu- 

Linella capitanensis, and Uvigerina modeloensis are 

not found above the Bolivina decurtata subzone, and 

Uvigerina hannai is not found below the Bolivina 

goudkqffi subzone. Bolivina goudkqffi is restricted ap 

parently to the subzone named for it. A marked in 

crease in the number of specimens of Bolivina seminuda, 

Bolivina sinuata, Cassidulina modeloensis, and Planu- 

lai'ia cushmani and a falling off of Bolivina hughesi 

seem also to characterize that subzone. 

MOLLUSKS 

Impressions and molds of the small thin-shelled deep- 

water scallop Delectopecten were collected at locality 20. 

They were cited in the preliminary paper 77 as Delec- 

opecten pedroanus. They are now identified, however, 

as Hyalopecten (Delectopecten) aff. H. peckhami.''8 

Similar material in the collections of the California 

Academy of Sciences (California-Acad. Sci. No. 1894) 

from a locality about 220 yards northwest of the end of 

the breakwater at Cabrillo Beach, close to locality 19a 

of the present report, appears to represent the same 

form. 79 In 1856 Trask 80 described three forms of scal 

lops from the east coast of the Palos Verdes Hills and 

believed the strata to be of Cretaceous age. The three 

forms are regarded as one species, which is cited as 

Hyalopecten^(Delectopecten) pedroanus. Trask's speci 

mens evidently came from the lower part of the Val 

monte diatomite or the upper part of the Altamira shale 

at Cabrillo Beach, for that is the only locality on the 

east coast where the dip is as steep as recorded by Trask 

(about 50°). According to his description and figures, 

H. pedroanus is a relatively large species that has strong 

concentric undulations and evidently has radial ribs. 

Specimens that show these characters have not been 

" Rankin, W.D., in Hoots, H. W., Geology of the eastern part of the Santa Monica 

Mountains, Los Angeles County, Calif.: U. S. Oeol. Survey Prof. Paper 165, pp. 103- 

104, 113, pi. 27, 1931. Kleinpell, R. M., Miocene stratigraphy of California, p. 130, 

Am. Assoc. Petroleum Geologists, Tulsa, Okla., 1038. 

» Rankin, W. D., Hughes, D. D., and Goudkoff, P. P., in Hoots, H. W., idem, 

p. 114. 

» Gallihor, E. W., Stratigraphic position of theMontcrey formation: Micropaleon- 

tologv Bull., vol. 2,'No. 4, pp. 71-74, 1931. 

"Kloinpoll, R. M., op. cit., p. 130. 

» Woodring, W. P., in Woodring, W. P., Bramlette, M. N., and Kleinpell, R, M., 

op. cit. (Am. Assoc. Petroleum Geologists Bull., vol. 20)p. 146. 

» Woodring, W. P., Lower Pliocene mollusks and echinoids from the Los Angeles 

Basin, Calif., and their inferred environment; U. S. Geol. Survey Prof. Paper 190, 

p. 39, 1938. 

«Idem. 

so Trask, J. B., Description of three new species of the genus Plagiosloma from the 

Cretaceous rocks of Los Angeles: California Acad. Sci. Proc., vol. 1, p. 86, 4 flgs., 1856. 


found in the Palos Verdes Hills since Trask's time. A 

similar form occurs, however, near the top of the Mio 

cene in the Los Angeles Basin subsurface section. 81 

VERTEBRATES 

Miller 82 has described three sea-birds found in diat 

omite assigned in the present report to the Valmonte 

member. Â shearwater (Puffinus diatomicus) collected 

at Cabrillo Beach was described originally from material 

in the diatomite of the Monterey shale at Lompoc, 

Santa Barbara County. A gannet (Sula stocktoni) and 

the oldest recorded albatross from America (Dinmedea? 

sp.) were collected in the quarry of the Dicalite Co. 

Miller also recorded the finding in the quarry of several 

specimens of a small cetacean similar to Lagenorhynchus. 

Sea lion remains from the quarry of the Dicalite Co. 

have been referred by Lyon 83 to Pontolis magnus. 

MALAGA MUDSTONE MEMBER 

The Malaga mudstone member 84 overlies the Val 

monte diatomite member and is the uppermost division 

of the Monterey shale in the Palos Verdes Hills. The 

type region is at Malaga Cove, at the northwest end 

of the hills, where the lower and upper parts of the 

member, but possibly not the entire thickness, are 

exposed. Unlike the other members of the Monterey, 

the Malaga is found only near the north and east 

margins of the hills. That it formerly extended over 

a much larger area, probably the entire area of the hills, 

is indicated by the absence of a shallow-water facies. 

Schist pebbles suggest, however, that a schist land area 

was close by. . 

The Malaga mudstone consists chiefly, and in some 

areas virtually entirely, of massive radiolarian mudstone 

or fine-grained siltstone. Relatively large globular 

Radiolaria and scattered diatoms are visible in field 

examination. Though the term "radiolarian mudstone" 

is used to differentiate the mudstone from ordinary 

mudstone, Radiolaria actually are a minor constituent. 

The mudstone is light chocolate brown or olive gray 

when dry and almost black when wet. The dry rock is 

greatly jointed and hackly. At Malaga Cove the 

Malaga member includes laminated diatomite and dia- 

tomaceous shale in thin streaks or in well-defined units 

several feet'thick. Such material was observed else 

where on the north slope of the hills but not in San 

Pedro. Limestone occurs as concretions and lenses in 

both massive mudstone and laminated diatomite. In 

the laminated rock laminae pass generally without 

interruption into the limestone. Vitric volcanic ash in 

thin layers is a minor constituent. Hard siliceous rocks 

were not observed at outcrop localities. 

The litholpgic change from the Valmonte to the 

Malaga is fairly abrupt at Malaga Cove. Limy phos- 

phatic nodules and schist and quartz pebbles occur at 

and just above the base of the Malaga. This material 

indicates slow deposition or nondeposition during the 

early period of the subsidence suggested by the deep- 

water aspect of the Malaga Foraminifera. Assignment 

of formation rank to the Malaga may be preferable to 

member rank in the Monterey. The prevailing litho- 

'8i Woodring, W. P., op. cit. (U. S. Geol. Survey Prof, paper 190), p. 41, pi. 6, flgs. 1, 

2, 1938. 

82 M iller, Loye, New bird horizons in California: California Univ. at Los Angeles 

Pub. Biol. Sci.. vol. 1, No. 5, pp. 73-80, 2 flgs., 1935. 

M Lvon, G. M., A Miocene sea lion from Lomita, Calif.: California Univ., Pub. 

Zoology, vol. 47, pp. 23-42, pis. 2-6, 2 flgs., 1941. 

s* Woodrinp, W. P., Bramlette, M. N., and Kleinpell, R. M., op . cit., (Am. Assoc. 

Petroleum Geologists Bull., vol. 20), p. 146.

38 


logic type in the Malaga is included, however, as a 

minor constituent in the underlying Valmonte, and 

some beds of laminated diatomite and diatomaceous 

shale, like that in the Valmonte, are included in the 

Malaga. 

The thickness of the Malaga mudstone is difficult to 

estimate. A thickness of about 150 feet above the base 

is represented in the southern syncline at Malaga Cove 

and about the same thickness at the top of the member 

on the south limb of the northern syncline. It is not 

known, however, whether these sections overlap. An 

apparently unbroken section of 325 feet, presumably 

near the top of the member, is exposed at the north end 

of Malaga Cove. Along most of the north slope of the 

hills the thickness is probably not more than.300 feet, 

but in part of that area the mudstone is overlapped by 

Pleistocene strata. In Isan Pedro, where the Malaga is 

overlapped, the thickness is as much, as 600 feet if the 

average dip is 15° and minor folds and faults are absent. 

The structure in that area is obscure/ however, and the 

thickness may be considerably less. 

The Malaga is rich in organic matter. Samples 

from Malaga Cove have a nitrogen content of 0.325 

per cent, 85 indicating an estimated percentage of 

organic matter of 7.8 86 the highest nitrogen content 

for California outcrop samples analyzed by Trask and. 

Patnode in their study of source beds of petroleum. 


MALAGA COVE AREA 

The base of the Malaga mudstone is well exposed on 

the north limb of the southern syncline at Malaga Cove 

(pis. 10, A; 11, A; fig. 7). As may be 'seen on plate 

11, A, there is some minor crumpling along the contact 

between the Valmonte and Malaga. About 20 feet 

above the beach a lens of flat limy phosphatic nodules 

1% feet thick is 1% feet above the base of the Malaga. 

Similar nodules are scattere.d between the base of the 

lens and the base of the member. The nodules are 2 

to 4 inches long and many contain leached Foramini- 

fera. A few pebbles of quartz and rotten schist are 

included among the nodules. A thicker lens of ap 

parently similar material higher on the cliff was not 

examined, owing to inaccessibility. A 3-inch layer of 

vitric volcanic ash is 15 feet above the base of the 

Malaga. A few Foraminifera were found in a lime 

stone concretion 18 feet above the base of the member 

(locality 23). Laminated diatomite in thin layers is a 

minor constituent at this locality and also on the south 

limb of the northern syncline (pi. 11, B}, where the 

uppermost part of the member is exposed. 

The anticlinal crest in the Malaga mudstone farther 

north along the cliff, shown in an earlier sketch,87 is 

now concealed by talus. The structure in that area 

is evidently not so simple as shown on the 1Q32 sketch. 

If it were, the overlying Repetto siltstone should 

appear on the north limb of the anticline. -Toward 

the north end of Malaga Cove the Malaga mudstone 

consists of alternating units .of massive radiolarian 

mudstone and laminated diatomite and diatomaceous 

shale (pi. 12, -A, B}. The massive units are almost 

invariably thicker than the laminated units. These 

strata are presumably ne&r the top of the Malaga. A 

section measured at that locality is as follows: 

8' Trask, P. D., and Patnode, H. W., Source beds of petroleum, pp. 176, 177, Am. 

Assoc. Petroleum Geologists, Tulsa, Okla., 1942. 

8« Nitrogen content X 24 (Idem, p. 33). ? 

" Woodring, W. P., San Pedro Hills: 10th Internat. Geol. Gong. Guidebook 15, 

fig. 6, 1932. 

Section of Malaga mudstone member of Monterey shale at north 

end of Malaga Cove 

Feet 

Massive radiolarian mudstone, overlapped by Pleistocene 

Sa'n Pedro (?) sand______________________________ 90 ' 

Laminated diatomite and diatomaceous shale, including 

a limestone concretion 1}£ feet thick 10 feet below top__ 19 

Massive radiolarian mudstone ________________________ 7 

Laminated diatomite and diatomaceous shale___________ 8J-. 

Massive radiolarian mudstone________________________ 22 

Laminated diatomite and diatomaceous shale___-_______ 1 

Massive radiolarian mudstone.___-_-__-----__________ 23 


a limestone concretion 8 inches thick at middle_______ 4 

Massive radiolarian mudstone-______ _ _______________ 3 

Unexposed- __________________________________________ 17 

Massive radiolarian mudstone, including a limestone concretion 

1% feet thick 6 feet above base_ _ ____________ 16 

Laminated diatomite and diatomaceous shale___________ 6 

Massive radiolarian mudstone__-_-'___---___________._ 10 


a limestone concretion \% feet thick at base__________ 7J_ 

Massive radiolarian mudstone._______________________ 6 

Laminated diatomite and diatomaceous shale___________ 1 

Massive radiolarian mudstone-_____-_---_-___________ 8 

Laminated diatomite and diatomaceous shale_-_________ 1% 

Massive radiolarian mudstone__-__--_-_--______-_____ 6 

Laminated diatomite and diatomaceous shale___________ 2}_ 

Massive radiolarian mudstone-_____-__________!______ 6 


a limestone concretion 1J4 feet thick 3 feet above base. 10 

Massive radiolarian mudstone____--------_____________ .8 

Laminated diatomite and diatomaceous silt____________ ' 2 

Massive radiolarian mudstone________________________ 6 


a limestone concretion 2}_ feet thick at top___________ 4 

Massive radiolarian mudstone._-___-_--__-__l____-___ 7 

Laminated diatomite and diatomaceous shale_______-___ 4>_ 

Massive radiolarian mudstone-_______________________ 7% 

Laminated diatomite and diatomaceous shale_________ 1]4 

Massive radiolarian mudstone-________L______________ 6 

Laminated diatomite and diatomaceous shale_---___---_ 12 

333K 

The "non-foraminiferal siliceous shale" at Malaga 

Cove described by Reed 88 includes both the Malaga 

mudstone and the Valmonte diatomite. Reed found 

that in some samples, presumably from the Malaga 

mudstone, Radiolaria, silicoflagellates, and sponge 

spicules are more abundant than diatoms, particularly 

in the very fine debris. He found volcanic glass hi 

small fragments to be abundant. He interpreted the 

small percentage of detrital minerals to indicate ulti 

mate, perhaps direct, derivation from a Franciscan (?) 

area. 

NORTH SLOPE OF HIL1S 

On the north slope of the hills the Malaga mud- 

stone is exposed in some of the deep, narrow ravines 

west of Walteria, in Sepulveda Canyon, and at various 

localities along the Gaffey anticline. At places thin 

layers of diatomite and diatomaceous shale are inter- 

bedded with the massive mudstone. Mudstone in a 

small outcrop in the trough of a steeply folded syn 

cline, on the east side of Agua Negra Canyon, 85 feet 

north of the Palos Verdes fence, may represent the 

Malaga or may be a mudstone unit near the top of the 

Valmonte. 

At a locality half a mile east of Palos Verdes Drive 

East an apparently steeply dipping limestone ledge 

that contains a few schist pebbles is thought to re 

present the base of the Malaga mudstone on the south 

limb of the Gaffey syncline. The locality is on the 

88 Reed, R. D., A siliceous shale formation from southern California: Jour. Geology 

ol. 36, pp. 345-353, figs. 1-3,1928.

nose of a spur on the north side of George F Canyon. 

The Malaga is exposed at nearby localities farther 

north, and diatomite, possibly representing the Val- 

monte,- was found on the spur 30 feet south of the 

limestone ledge. 

The Whites Point tunnel penetrated the Malaga 

mudstone along the Gaffey anticline. The wet rock 

hi the tunnel consists of black massive mudstone 

including scattered diatomaceous streaks, A zone of 

limestone concretions was observed on the south limb 

of the anticline. A thin band of black chert on the 

north limb is a minor constituent not seen at outcrop 

localities. 


In San Pedro the Malaga mudstone crops out in 

ravines and on the sea cliff at the Fort McArthur 

Lower Reservation. It was formerly visible in the sea 

cliff at Timms Point, where it is overlapped by Pleis 

tocene strata, but it is now concealed by fill. The best 

exposures in San Pedro, however, are in street cuts, 

such as those on Second Street between Gaffey and 

Cabrillo Avenues and nearby, where the dip is only a 

few degrees northeast. In the natural and artificial 

exposures the Malaga consists of massive mudstone 

containing limestone lenses and concretions. Bedded 

mudstone and siltstone are minor constituents. Well- 

preserved Foraminifera were collected from mudstone 

near the base of the member, on the north side of 

Cabrillo Avenue 75 feet north of Fourth Street (locality 

24), a locality found by Dr. Hampton Smith. A few 

Foraminifera were found near the exposed top of the 

member, in a limestone concretion on the south face of 

Timms Point at locality 25, now inaccessible. 

FOSSILS 

FORAMINIFERA 

Foraminifera appear to be rare in the Malaga mud- 

stone. Well-preserved material from locality 24 and 

a small collection from locality 25, both in San Pedro, 

are assigned by Kleinpell to the Bolivina obligua zone 89 

(zone I of preliminary paper) . 90 A fauna similar to that 

at locality 24 was found recently on the Gaffey anticline 

near the Los Angeles city boundary. A few poorly 

preserved species from locality 23 are grouped with the 

others on the basis of stratigraphic occurrence. Locality 

24 is estimated to be 35 feet above the base of the 

Malaga, and locality 25 is 25 feet below the base of the 

overlapping Pleistocene formation at Timms Point. 

The Bolivina obligua zone, therefore, includes approx 

imately the entire thickness of the Malaga mudstone in 

the San Pedro area, where that member appears to be 

thicker than in other parts of the hills. 

The following table gives the list of species identified 

by Kleinpell: 

89 Bramlotto prefers to assign Foraminifera from the Malaga mudstone to the lower 

part of Kloinpell's Delmontian stage and the Bolivina obliqua zone to the upper part. 

(See discussion in Woodring, W. P., Bramlette, M. N., and Lohman, 1C E., 

Stratigraphy and paleontology of Santa Maria district, Calif.: Am. Assoc. Petroleum 

Geologists Bull., vol. 27, No. 10, pp. 1346, 1349-1350, 1943.) 

08 Woodrlng, W. P., Bramlette, M. N., and Kleinpell, R. M., Miocene stratigraphy 

and paleontology of Palos Verdes Hills, Calif.: Am. Assoc. Petroleum Geologists 

Bull., vol. 20, No. 2, pp. 125-149,1936. 


Foramtmfera from Malaga mudstone member of Monterey shale 

[Identifications by R. M. Kleinpell. R, Rare; F, few; C, common; A, abundant] 

Species 

Bathysiphon? sp.............~ -.-_--_---_-...-.-...-...__....-. 

Dentalinacf. D. filiformis (d'Orbigny) (Dentalina sp.')........ 

Nodosaria tympaniplectriformisSchwager (cf.) (Kleinpell, pi. 22 

flg. 2)3........................................................ 

Frond icularia ad vena Cushman................................ 

Buliminella dubia Barbat and Johnson...._.___...____________ 

Buliminella subfusiformis Cushman? ("Buliminella sp." Rankin 

Bulimina inflata Scguenza..._.......-.._.........______.. 

Bulimina montereyana var. delmonteensis Kleinpell? (Bulimina 

cf. B. affinis d'Orbigny of Brady).__.._._............... 

Bulimina ovula d'Orbigny__................................. 

Bulimina ovula var. pedroana Kleinpell (Bulimina aff. B. ovula 

d'Orbigny) (Kleinpell, pi. 22, fig. 13) 3_-------------------- 

Virgulina californieusis Cushman............................... 

Virgulina delmonteensis Cushman and Galliher................ 

Bolivina malagaensis Kleinpell (Bolivina aff. B. ad vena Gush- 

man) (Kleinpell, pi. 22, figs. 3, 7) 3_...-__._.................... 

Bolivina seminuda Cushman................................... 

Bolivina sinuata Galloway and Wissler......................... 

Uvigerina hannai Kleinpell (Uyigerinaafl. U. hootsi Rankin)... 

Uvigerina hootsi Rankin.....1................................. 

Uvigerina segundoensis Cushman and Galliher................. 

Valvulineria araucana var. malagaensis Kleinpell (Valvulineria 

afl. V. araucana (d'Orbigny)) (Kleinpell, pi. 22, figs. 10-12)3... 

Gyroidina soldanii var. rotundimargo R. E. and K. C. Stcwart.. 

Eponides multicameratus Kleinpell ("Eponides aff. E. broeckiana 

(Karrer)" Rankin)--.--................................. 

Eponides healdi R. E. and K. C. Stcwart. ..................... 

Eponides keenani Cushman and Kleinpell_.................. 

Cassidulina delicata Cushman_.........- ....................'. 

Cassiduliua modeloensis Rankin................................ 

Chilostomella cf. C. ovoidea Reuss (Chilostomella? cf. C. oolina 

Schwager) (Kleinpell, pi. 22, fig. 8) 3........................... 

Pullenia pedroana Klciupell (Pullcniacf. P. Salisbury! R. E. and 

K. C. Stewart) (Kleinpell, pi. 22, figs. 14,15)3................. 

Globigerina bulloides d' Orbigny...................._......... 

Planulina ornata (d'Orbigny)._.............................. 

Localities 

Bolivina obliqua 

zone 

23' 24 25 

1 Zonal position uncertain. 

2 Names in parenthesos were used in preliminary paper (Am. Assoc. Petroleum 

Geologists, Bull., vol. 20, No. 2, pp. 125-149, 1936). 

3 Kleinpell, R. M., Miocene stratigraphy of California, Am. Assoc. Petroleum 

Geologists, Tulsa, Okla., 1938. The citations in the table refer to illustrations of 

specimens from the Palos Verdes Hills. / 

Kleinpell's comments ere summarized as follows: 

The assemblages from localities 24 and 25 may be 

correlated with the fauna of the typical Bolivina obligua 

zone in Hoots' lithologic unit 18 of the upper member 

of the Modelo formation (Monterey shale of some geol 

ogists) at the north edge of the Santa Monica Moun 

tains, as listed by Rankin. 91 They may also be cor 

related with the fauna in the upper shale member of the 

Modelo formation in the type region in Modelo Canyon, 

Ventura County, 92 and with that in the lower part of 

the Reef Ridge shale of the Coalinga district in the San 

Joaquin Valley. 93 

ENVIRONMENT S UGGESTED B Y FOSSILS 

Suggestions concerning the environment of the 

Monterey Foraminifera in the following discussion are 

based on comments prepared by Kleinpell. 

Sandstones in the middle and upper parts of the 

Altamira shale member contain shallow-water mollusks. 

That the shale in the upper part of the Altamira between 

81 Rankin, W. D., in Hoots, H. W., Geology of the eastern part of the Santa Monica- 

Mountains, Los Angeles County, Calif.: U. S. Geol. Survey Prof. Paper 165, pp. 

113-114, 1931. Kleinpell, R. M., Miocene stratigraphy of California, p. 134, Am.. 

Assoc. Petroleum Geologists, Tulsa, Okla., 1938. 

" Rankin, W. D., op. cit. 

" Kleinpell, R. M., in Woodring, W. P., Stewart. Ralph, and Richards, R. W.,. 

Geology of the Kettleman Hills oil field, Calif.: stratigraphy, paleontology, and 

structure: U. S. Geol. Survey Prof. Paper 195, p. 121,1940 [19411.

40 GEOLOGY AND PALEONTOLOGY.OF PALOS VERDES HILLS, CALIFORNIA 

the two thick sandstone units at Point Fermin was de 

posited in comparatively shallow-water is indicated by 

the presence of Elphidium and other Foraminifera. 

The peculiar faunal facies characterized by very small 

specimens of Foraminifera at localities 6 and 8 in the 

middle part of the Altamira shale is comparable to the 

facies shown by species that inhabit seaweed forests in 

the modern oceans and may indicate a similar habitat. 

The Foraminifera at other localities in silty shale and 

siltstone of the three parts of the Altamira shale indicate 

moderate depth, possibly near the 100-fathom line. 

The fauna at locality 5, however, suggests somewhat 

greater depth, perhaps between 300 and 500 fathoms. 

That locality represents diatomaceous silt in the middle 

part of the Altamira, evidently near the horizon of the 

Miraleste tuff. 

The Foraminifera of the Valmonte diatomite member 

point to deposition at depths of 300 to 500 fathoms. 

Modern forms related to the thin-shelled scallop Hyal- 

opecten aff. H. peckhami have been dredged along the 

coast of Oregon and California at depths of 100 to al 

most 1,100 fathoms. 

The mudstone of the Malaga member was deposited 

evidently in deeper water: than the sediments of the 

other two members. The abundance of Bathysiphon, 

Bulimina inflata, Cassidulina delicata, Eponides healdi, 

and Gyroidina soldanii rotundimargo at locality 24 

suggests depths of 500 fathoms or more. It is assumed 

that lithologically similar mudstone at other localities 

represents deposition at considerable depths. The 

abundance of shallow-water bottom-dwelling diatoms 

in diatomite from Malaga Cove has been cited as 

evidence for deposition in shallow water. 94 It is not 

known whether the diatomite examined was collected 

from the Valmonte member or the Malaga member. 

The abundance of shallow-water attached diatoms is 

not incompatible, however, with ultimate deposition in 

deep water. Seaweeds to which such diatoms are 

attached may be torn loose and float a considerable 

distance from shore. -It is suggested that a comparitive 

study of diatoms in the mudstone and laminated dia 

tomite of the Malaga member and in different laminae 

in the diatomite of both Malaga and Valmonte members 

might be useful in attempting to reconstruct environ 

mental conditions. It appears improbable that the 

many alternating units of mudstone and diatomite in 

the Malaga member at the north end of Malaga Cove 

indicate alternating deep- and shallow water. 

The foraminiferal faunas of the lower and middle 

parts of the Altamira shale are characterized by forms 

whose modern analogs are found in .subtropical and 

tropical American waters. These forms are not known 

to occur in the upper part of the Altamira nor in the 

younger members. That the difference is not due to 

difference in depth facies is indicated by the absence of 

the warm-water forms in both shallow-water and deep- 

water facies in the upper part of the Altamira. Sand 

stone in the middle part of the Altamira contains a 

mollusk fauna including a notable number of tropical 

genera. Faunas of comparable size have not been 

found, however, in other parts of the Monterey in the 


AGE AND CORRELATION 

Age assignments and correlation of the Monterey 

shale of the Palos Verdes Hills are based on Kleinpell's 

M Hanna, G. D., The age of the diatom-bearing shales at Malaga Cove, Los Angeles 

County, Calif.: Am. Assoc. Petroleum Geologists Bull., vol. 12, p. 1111,1928. 

identifications of the foraininiferal zones. His views 

are included in the comments on preceding pages and 

are summarized in the correlation chart in his publica 

tion. 95 According to Kleinpell's identifications and 

according to usual Coast Range usage, the M.onterey 

shale of the Palos Verdes Hills is of late middle to late 

upper Miocene age, the division between middle and 

upper Miocene being between the middle and upper 

parts of the Altamira shale member. Strata in the 

upper part of the Altamira are correlated with the lower 

part of the Modelo formation of the Santa Monica 

Mountains, selected by Kleinpell as the type region of 

his Bolivina modeloensis zone, the lowest zone recognized 

in the upper Miocene. 

The mollusks found in sandstone of the middle part 

of the Altamira shale are of no assistance in correlation, 

as a similar fauna is unknown elsewhere in the Coast 

Ranges. 

Though phosphatic shale is most abundant in the 

upper part of the Altamira shale, similar material and 

phosphatic mudstone occur also in the middle part. 

It is doubtful whether the abundance of phosphatic 

shale alone is a safe basis for correlation. Foraminifera 

from the upper part of the Altimira indicate, however, 

that the phosphate-rich strata in the Palos Verdes 

Hills are of the same age as phosphatic shale overlying 

schist in the Torrance, El Segundo, and Playa del Rey 

oil fields, 96 and at the base of the Modelo formation 

in the Santa Monica Mountains. 

PLIOCENE SERIES 

BEPETTO SILTSTONE 

GENERAL FEATURES 

The Pliocene series has a meager representation in 

the Palos Verdes Hills. A maximum exposed thick 

ness of about 150 feet of siltstone assigned to that 

series represents a greatly condensed and incomplete 

section of the lower Pliocene Repetto formation. In 

the Los Angeles Basin the Repetto formation has a 

thickness of as much as 4,000 or 5,000 feet but thins 

.southward toward the Palos Verdes Hills. In the 

basin the upper Pliocene is represented by the Pico 

formation, ranging in thickness from several hundred 

to 3,000 feet. The Pico formation is missing in the 


The type region of the Repetto formation is in the 

Repetto Hills, on the north border of the Los Angeles 

Basin.'97 In that region the formation consists of 

2,000 to 3,000 feet of siltstone and rests conformably 

on diatomaceous shale referred to the upper Miocene. 

Farther east in the Puente Hills the Repetto includes 

thick beds of conglomerate and sandstone. In the 

subsurface section in the basin it includes the sand 

stones that yield the oil produced in most of the major 

fields. Owing to its economic importance the sub 

surface Repetto has been studied exhaustively. Numer 

ous faunal subdivisions, based on abundant well- 

preserved Foramiuifera, are recognized and used in 

oilfield correlations. 

In the Palos Verdes Hills the Repetto consjsts 

entirely of siltstone, and the term "Repetto siltstone" 

85 Kleinpell, R. M., Miocene stratigraphy of California, fig. 14, (in pocket, column 

under heading "Los Angeles Basin") Am. Assoc.. Petroleum Geologists, Tulsa, 

Okla., 1938. 

w Wissler, S. G., Stratigraphic formations [relations] of the producing zones of the 

Los Angeles Basin oil fields: California Div. Mines Bull. 118, pt. 2, p. 222, 1941. 

87 For a brief description of the Repetto formation in the Los Angeles Basin and on 

its borders and for citations to literature see Woodring, W. P., Lower Pliocene mol 

lusks and echinoids from the Los Angeles Basin, Calif., and their inferred environ 

ment: U. S. Geol. Survey Prof. Paper 190, pp. 3-6,1938.

is used for the formation in that area. The Repetto 

siltstone disconformably overlies the Malaga mudstone 

member of the Monterey shale and is unconformably 

overlain by Pleistocene strata. Though the contact 

between the Malaga and Repetto appears to be grada- 

tional, faim al^ data indicate a discontinuity of consider 

able magnitude. The Repetto is found at Malaga Cove 

and at other localities near the north border of the hills, 

extending eastward to an area straddling Palos Verdes 

Drive East. At many places between Malaga Cove 

and Palos Verdes Drive East and in the entire area east 

and southeast of Palos Verdes Drive East Pleistocene 

formations rest directly on the Miocene, the Repetto 

being overlapped. How far south the Repetto orig 

inally extended is not known, but it covered probably 

the entire area of the hills. The fossils indicate that the 

sediments in the Palos Verdes Hills were laid down in 

deep water. Scattered schist pebbles were apparently 

derived from a schist area perhaps to the south or west 

of the present Palos Verdes Hills. It is doubtful 

whether the original thickness of the Repetto prior to 

the erosion that preceded the' deposition of Pleistocene 

strata was much greater than the present thickness at 

Malaga Cove. 

The Repetto consists of soft, massive, glauconitic 

foraminiferal siltstone. The dry rock is bluish gray 

on fresh surfaces and buff on weathered surfaces. The 

coarser grain of the sediments, the abundance of glau- 

conito grains and Foraminifera, and the scarcity or 

absence of Radiolaria and diatoms distinguish the 

Repetto siltstone from the Malaga mudstone. The 

differences are in general readily apparent, but out 

crops of small extent may consist of rocks that are not 

typical, and in such outcrops the two units may be 

difficult to distinguish. 


MALAGA COVE 

The best and most readily accessible exposures of 

the Repetto siltstone are at Malaga Cove, where the 

Repetto disconformably overlies the Malaga mudstone 

S. 

_ _ ... ''''' . . . -.-. 

V '. V VV '.' '.' isionmarine terrace cover and_ dune sand _ I Pleistocene to Recent) .'. 'y .' - /_. 

FIGURE 9. Rot otto siltstone in northern syncline at Malaga Cove. 

"member of the Monterey in the northern syncline (pis. 

10, A; 12, C; figs. 7, 9). The Repetto consists of soft 

massive bluish-gray siltstone. Glauconite grains and 

well-preserved Foraminifera may be found in virtually 

,any hand specimen. A thickness of 100 feet is exposed, 

;and it is estimated that an additional thickness of about 


50 feet in the trough of the syncline is concealed by 

slump at the top of the cliff. At accessible places on 

the cliff the contact with the underlying Malaga mud- 

stone appears to be gradational through a thickness of 

a few inches. About half way up the cliff, on the 

south limb of the syncline, a lens 01 sand a foot thick, 

streaked with siltstone, is at or near the base of the 

Repetto. Another 1-foot sandy zone is 17 feet above 

the base. Two thin beds of vitric volcanic ash varying 

in thickness from 2 to 6 inches are in. the Repetto, the 

lower bed 39 feet above the base of the formation and 

the upper bed 33 feet higher. Both beds are at places 

in the form of discontinuous short stringers. The ash 

is discernible only at times when the cliff face is clean 

and fresh. The siltstone contains a few pebbles of 

schist, quartz, and black basaltic rock 1 to 4 inches 

long. Limestone occurs as concretions, which are 

much less abundant than in the Malaga mudstone. 

The concretions contain glauconite grains and Forami- 

nifera filled with calcite. 

The "foraminiferal rock" at Malaga Cove described 

by Reed 98 is the Repetto siltstone. He estimated that 

Foraminifera make up 20 percent of the samples ex 

amined and echinoid spines and siliceous organisms 

diatoms, Radiolaria, silicoflagellates, and sponge spic- 

ules: 5 percent. Glauconite was found to be abundant 

both as grains and in the fine-grained matrix. The de- 

trital mineral grams, including blue soda amphibole, 

were interpreted as indicating ultimate or perhaps 

direct derivation from avFranciscan (?) area. 

Foraminifera were collected from the lower 85 feet 

of the formation on the south limb and in the trough 

of the syncline (locality 26). A few specimens of a 

large thin-shelled clam, Lima hamlini, were collected 

5 to 10 feet below the lower bed of volcanic ash on the 

north limb of the syncline, just north" of the trough 

(locality 27). A vertebra found by Dr. H. W. Hoots 

about 10 feet above the base of the formation is identi 

fied by Dr. Remington Kellogg as a caudal vertebra of 

a whale. 

RAVINE WEST OF HAWTHORNE AVENUE NEAR WAITERIA 

The Repetto siltstone crops out in a small area at 

the head of a ravine on the north slope of the hills, the 

fourth ravine northwest of Hawthorne Avenue. Frag 

mentary remains of Lima hamlini as well as Foraminif 

era were found at this locality. The siltstone is over 

lain by Pleistocene sandy marl. In other ravines in 

this area the Pleistocene strata rest on Miocene rocks. 

IOMITA QUARRY-PALOS VERDES TRIVE EAST AREA 

la the Lomita quarry-Palos Verdes Drive East area 

the Repetto siltstone is found on the flanks of the 

Gaffey syncline and locally on the north flank of the 

Gaffey anticline. Only two exposures were observed 

near the Lomita quarry, one in the ravine north of the 

quarry and the .other in a cut along the road leading to 

the quarry. At both localities the siltstone is over 

lain by Pleistocene calcareous beds. Several outcrops 

were found along Palos Verdes Drive East and in nearby 

ravines, but contacts with overlying and underlying 

formations are not exposed. Foraminifera are particu 

larly abundant at locality 28, near Palos Verdes Drive 

East. 

8« Reed, R. D., A siliceous shale formation from southern California: Jour. Geology 

vol. 36, pp. 353-357, fig. 4, 1928.


FOSSILS 

FORAMIWIFEBA 

Foraminifera are abundant in the Repetto siltstone. 

The faunas are the same as those in the Repetto 

of Los Angeles Basin oil fields, where the general 

succession of foraminiferal zones was known before 

Foraminifera were found in the outcrop section along 

the borders of the basin. 

MOLLUSKS 

Specimens' of Lima hamlini were collected at Malaga 

Cove (locality 28), and remains of that species too 

fragmentary to collect were recognized in a ravine west 

of Hawthorne Avenue. Lima hamlini " is closely 

related to L. agassizii, dredged in the Gulf of Panama 

at a depth of 322 fathoms. 

ENVIRONMENT SUGGESTED BY FOSSILS 

The Repetto siltstone of the Palos Verdes Hills 

contains the characteristic Foraminifera of the Repetto 

formation of the Los Angeles and Ventura Basins. 

According to Natland's analysis 1 of the Repetto Fo 

raminifera, they are similar to forms' living at depths 

of about 6,500 to 8,340 feet off the California coast. 

Lima hamlini is the most widespread of a group of 

Los Angeles Repetto mollusks that suggest depths of 

300 to 600 fathoms (roughly 2,000 to 4',000 feet). 2 

AGE AND CORRELATION 

On the basis of a twofold subdivision of the Pliocene 

of the Los Angeles Basin, the Repetto is lower Pliocene. 

The lowermost 85 feet of an estimated thickness of 

150 feet of Repetto siltstone at Malaga Cove was 

sampled for Foraminifera with the assistance of H. L. 

Driver, G. C. Ferguson, H. W. Hoots, and S. G. 

Wissler. According to Wissler,3 the entire lower 

Repetto and the basal part of the middle Repetto are 

missing, and the missing divisions are represented by 

150 feet of strata in the nearby Torrance field and by 

500 feet in the Dominguez field. 

PLEISTOCENE SERIES 

PRINCIPAL SUBDIVISIONS 

The Pleistocene deposits of the Palos Verdes Hills are 

exceptionally fossiliferous, and in part of the area they 

were studied exhaustively by Arnold, whose great 

monograph 4 on the stratigraphy and paleontology of 

these deposits has played an important part hi the de 

velopment of geologic investigations in the Coast 

Ranges. Arnold studied the section exposed along the 

San Pedro water front and on Deadman Island and 

described the fossils collected during a period of many 

years by him and his father, Delos Arnold. Arnold's 

stratigraphic units are still recognized, but the nomen 

clature adopted in the present report is different from 

that used by him, as shown in the following table: 

«» Woodring, W. P., op. cit. (U S. Geol. Survey Prof. Paper 190), pp. 47-49. 

i Natland, M. L., The temperature and depth distribution of some Recent and 

fossil Foraminifera in the southern California region: California Univ., Seripps Inst. 

Oceanography Bull., Tech. ser., vol. 3, pp. 225-230,1 table, 1933; in Cushman, J. A., 

Report of the Committee on Micropaleontology: Nat. Research Council Div. Geology 

and Geography Rept. 1936-1937, app. E., p. 6,1937. 

a Woodring, W. P., op. cit., pp. 13-16. 

a Wissler, S. G., Stratigraphic formations [relations] of the producing zones of the 

Los Angeles Basin oil fields: California Div. Mines Bull. 118, pt. 2, pp. 217-218,1941. 

« Arnold, Ralph, The paleontology and stratigraphy of the marine Pliocene and 

Pleistocene of San Pedro, Calif.: California Acad. Sci. Mem., vol. 3, 420 pp.. 37 pis. 

1903. (Reprint Leland Stanford Jr. Univ. Contr. Biol. Hopkins Seaside Lab., 

No. 31, 1903.) 

Stratigraphic nomenclature used by Arnold for formations assigned 

to Pliocene and Pleistocene and nomenclature used in present 

report for corresponding units. 

Pleistocene] 

2 a 

£8 

2 CD a 

(VC 

a S! 

03 

Arnold, 1903 

Upper San Pedro series 

Lower San Pedro series 

Sandstone at Deadman Island and 

Timms Point 

This report 

Palos Verdes sand 

San Pedro sand ' 

Timms Point silt 

CD W r] 

P. CO 0? 

Pleis Lower 

tocene 

The marine strata assigned to the Pleistocene in this 

report include two principal subdivisions designated 

lower Pleistocene and upper Pleistocene-. These sub 

divisions and then: stratigraphic units are shown in the 

following table: 

Marine^Pleistocene deposits in Palos Verdes Hills 

Principal subdivisions 

Upper Pleistocene. 

Lower Pleistocene. 

Stratigraphic units 

Marine deposits on marine terraces, including those 

on youngest terrace the Palos Verdes sand. 

___________ Unconformity ___________ 

San Pedro sand. 


Timms 

Point 

silt. 

As explained under the heading "Age and correlation" 

(p. 96), these deposits are considered Pleistocene in 

terms of the succession of marine formations on the 

Pacific coast. The subdivisions of the Pleistocene 

have, however, only a relative age significance. 

Arnold's lower San Pedro series is now designated 

the San Pedro sand, and the Timms Point silt is his 

Pliocene. The Lomita marl is a calcareous facies that 

is not present along the San Pedro water front a,nd, 

therefore, was not observed by Arnold. The upper 

Pleistocene terrace deposits older than the Palos Verdes 

sand also were not included in his studies. 

Arnold recognized the unconformity between his 

lower San Pedro series and his upper San Pedro series, 

that is, between the San Pedro sand and the Palos 

Verdes sand. As his work was limited to the water 

front, he did not recognize evidently the relative mag 

nitude of the unconformity in terms of the events that 

took place during the time interval represented by the 

unconformity. If the geologic history of the Palos 

Verdes Hills is correctly interpreted, these events in 

cluded deformation; almost complete submergence or 

probably complete submergence of the area now con 

stituting the Palos Verdes Hills; and intermittent emer 

gence during which the series of marine terraces were 

formed and the marine deposits now found on most of 

them were laid down, the Palos Verdes sand constituting 

the marine deposits on the lowest and most extensive 

terrace on the landward side of the hills. 

The exposures of the Pleistocene formations are 

described as they were found during the course of field 

work in 1930, supplemented by observations in 1933 

and 1935 and by scattered observations during the

spring of 1938. Owing to urban and other develop 

ments exposures change rapidly or are completely ob 

literated, particularly in San Pedro. Even under 

natural conditions exposures are rapidly obscured by 

slump and talus or by growth of vegetation. On the 

other hand, new and important exposures are contin 

ually being uncovered. At least along the water front, 

however, the net result is a distinct loss geologically. 

Many of Arnold's famous fossil localities are not acces 

sible, Deadman Island being, for example, no longer in 

existence. Small areas of fossiliferous San Pedro sand 

at Second and Beacon Streets, bounded by streets ex 

cavated to grade, are a few hundred feet inland from 

Arnold's lower San Pedro locality (now destroyed) at the 

San Pedro blufi\ By 1943 this entire area was exca 

vated to grade and exposures of the San Pedro sand, 

comparable to Arnold's San Pedro Bluff locality, can no 

longer bo seen. Arnold's upper San Pedro locality at 

the north end of San Pedro bluff, near the lumber yard 

(locality 113, on the east side of Harbor Boulevard), has 

been destroyed recently. His upper San Pedro locality 

at Crawfish George's (locality 108, at the north bound 

ary of the Fort McArthur Lower Reservation) and his 

Pliocene locality at Timms Point were still accessible in 

1938, but the point at Timms Point is concealed by fill. 

LOMITA MARL, TIMMS POINT SILT, AND SAN PEDRO 

SAND 


STRATIQKAPHIC RELATIONS 

Strata assigned to the lower Pleistocene are found 

along and near the northeast and north borders of the 

hills from San Pedro northwestward to Malaga Cove. 

They lie unconformably on the Repetto siltstone or lap 

up on different members of the Monterey shale. At 

many places they are concealed by overlapping terrace 

deposits. Sections of the lower Pleistocene strata are 

shown on plate 13. 

At most localities the lower Pleistocene deposits con 

sist chiefly or entirely of the San Pedro sand. At places 

calcareous beds or silt, or both, of varying thickness are 

found at the base of the section. The calcareous beds 

are designated the Lomita marl, and the silt is desig 

nated the Timms Point silt. In central San Pedro, 

where the three units Lomita marl, Timms Point silt, 

and San Pedro sand are superimposed, they are found 

in upward sequence in the order named. If each unit 

represents a distinct time interval, discontinuities 

might be expected to account for the varying thickness 

of the Lomita marl and Timms Point silt and for their 

local absence. With the following exceptions, however, 

no marked discontinuities are apparent. On Deadman 

Island, which has been destroyed, the San Pedro sand 

overlay the Timms Point silt along an abrupt and 

irregular contact. At Lomita quarry sand doubtfully 

identified as the San Pedro appears to overlie the Lomita 

unconformably. At other localities where contacts be 

tween the three units were observed the change in lith- 

ology is generally gradational. Though continuous 

exposures along the strike are not extensive, the ob 

served relations appear to be most satisfactorily ex 

plained by the inference that the lower part of the San 

Pedro sand grades laterally into the Lomita marl and 

Timms Point silt and by the further inference that 

minor discontinuities are found locally between the 

three units and also within them, as shown in figure 10. 

Inasmuch as the Lomita marl and Timms Point silt are 

PLEISTOCENE SERIES 43 

considered facies of a major stratigraphic unit, the San 

Pedro sand, the view that they are to be assigned 

member rank under the San Pedro sand may be justified. 

To avoid violation of current usage and also to avoid 

cumbersome stratigraphic ramrs, the three units are- 

assigned formatior rank. 

GENERAI CHARACTER AND DISTRIBUTION 

The maximum outcrop thickness of the lower Pleis 

tocene strata is not more than 350 feet; the maximum 

subsurface thickness is estimated to be about 600 feet. 

The thickness varies, however, from place to place- 

owing to the unconformity at the top. 

Wherever the Lomita marl was found it is at the base 

of the lower Pleistocene deposits. It has an extensive- 

but discontinuous distribution from San Pedro to the- 

region west of Walteria. It is thickest in the Gaffey 

syncline and in San Pedro. On the north flank of the- 

Gaffey anticline it is absent generally or if present is 

thin. The maximum exposed thickness is 60 to 70 feet. 

The computed thickness in San Pedro is about 100 feet.. 

Subsurface sections in the Gaffey syncline show a. 

thickness as great as 275 feet. 

The Timms Point silt is the least extensive of the 

three units. The only area of considerable size is in 

San Pedro, where the silt rests oh the Miocene or over 

lies the Lomita marl. Isolated exposures of strata, 

assignable to the Timms Point silt were found on the- 

north flank of the Gaffey anticline and along the north 

border of the hills near Agua Magna Canyon. The 

exposed thickness in San Pedro is 30 to 80 feet, but the- 

maximum computed thickness is about 120 feet. 

The San Pedro sand is found throughout the area, 

where the lower Pleistocene strata are exposed. It 

rests directly on the Pliocene or Miocene or overlies the- 

Lomita marl or Timms Point silt. The maximum ex 

posed thickness is about 175 feet. In subsurface sec 

tions the thickness is as much as 300 feet. 

The Lomita marl consists of a variety of calcareous 

rocks, principally marl and calcareous sand. The term 

"calcareous sand" is used for unconsolidated calcareous 

material of sand or granule size -composed chiefly of 

calcareous organic remains calcareous algae, Forami- 

nifera, Bryozoa, small shells, and shell fragments. 

There appears to be no simple term for such calcareous, 

sediments. The calcareous sand of the Lomita marl is 

representative of a particular type hi that the calcareous, 

material which is its principal constituent is derived 

from contemporaneous or penecontemporaneous organ 

isms. The term " calcarenite" 5 has been proposed for 

clastic limestone or dolomite composed of coral sand, 

shell sand, or of lime sand derived from the erosion of 

older limestones. That term is, however, hardly suit 

able for the unconsolidated sediments under discussion, 

and a special term such as "biocalcigranulyte" 8 is 

cumbersone and meaningless to most geologists. 

The proportions of different organic constituents in 

the calcareous sediments change from place to place 

and from layer to layer. Foraminifera or mollusks 

are the usual most abundant constituents; locally 

Bryozoa or calcareous algae are most abundant. 

Echinoids, represented generally by spines, are less 

frequent. Corals, brachiopods, ostracodes, barnacles, 

and decapod crustaceans are relatively rare. At some 

places the calcareous sediments contain little detrital 

material, about 10 percent or less; at other places they 

6 Grabau, A. W., Paleozoic coral reefs: Geol. Soc. America Bull., vol. 14, p. 349,1903. 

6 Grabau, A. W., Principles of stratigraphy, 2d ed., p. 283, New York, 1924.

44 

NW. 


GAFFEY SYNCLINE 

1 

^.'.YjÎLl'.:^ >'. ' ' 

-{ - - ' i* - /.'.*.'.' 

. , . . ^j . ...... j_* ........ 

LOMITA MARL-Y-'.' ' ' ' ' ' 

4r^j^^-'_2='-:v'sAN' 

iî^S^: 

GAFFEY STREET, 

SAN PEDRO 

SECOND STREET, 

SAN PEDRO 

TIMMS POINT 

i 

uZ^ L^înf7 - i.^:.-_L-l- ' ' ' 

.-'. IX-'-. ' .' .- .'j-i/^r. .'-TT ^f Ljrr1 -~rj^"r "=^ i= ; TrT: ~:^P:irriTy_1J 

0% 0 . oVo 0 0 0 0. ....... 

/. . 'SAN '. PEDRO -SANI v.- :-\ :.-'.':.':'.-'/.-'.-'.- . : '. . . '. . .-. ::. .-. :'. . . '. '. 

^ . ::::::.^^--. . . . . . . . . . . . ,'. :. :::. . . : . . :. . : . . :::. . :: 

.v. .-.-. -.v: : : ::. . . .4V-:: : . . . . ::. . . . . . . . . . . . . . . . . . . . . . . . . . . 

''.'.' . . .'.'.'.'. .'.'' '-^--rrr ' ' ^ r-r~. V '. ..'. .'.'.'.': .' .' .' .' .'.' ' 

. . :;.-. .-. . . . .^- - ...- -.... . .v.v.: 

. . . . . .-. .-. . . . . . . .'_. ...: -... :-ii ... -^V... flMMS POINf SMT-A 

PEDRO'SAND.' '. '. '. '. . . . . '. irf-^fT^-T^- .ZE^.f^- ^-^.^ f^Zli 

.'. .'. . .. . . . . .: . -Jz^r LOMITA MARL J. "r . . iu. -r^-r -r^ V- '. 

-=-= i i.-r-rr- i i r-1- , -1- , J r' ,- i ' > -L~ . ' T- ' -^ ' =-v^ 

100 Feet 

FIGURE 10. Chart showing inferred relations of Lomita marl, Timms Point silt, and San Pedro sand. 

sandy or silty. In excavations or fresh outcrops 

the calcareous sediments are unc'emented or poorly 

cemented. In most natural outcrops, however, they 

consist of hard rocks cemented by secondarily deposited 

calcareous material. At many localities glauconite 

and limy phosphatic nodules are abundant in some 

layers. The Lomita marl includes also beds of gravel 

consisting chiefly or entirely of limestone pebbles and 

cobbles derived from the Monterey shale. Locally 

huge boulders of soft Miocene mudstone and Pliocene 

siltstone are embedded in calcareous strata. The 

petrology of the calcareous sediments has been studied 

by Reed, 7 but only summaries of the results of his 

studies have been published. 

The Timms Point silt consists of brownish generally, 

massive sandy silt and silty sand. At Timms Point 

the silt is marly near the base of the member. At 

that locality the silt and sand contain pebbles of 

limestone like that in the underlying Miocene strata. 

The San Pedro sand is made up chiefly of regularly 

bedded and cross-bedded sand, but includes gravel,^ 

silty sand, and silt. In San Pedro, where the San 

Pedro sand overlies the Timms Point silt, a transition 

zone between the two units consists of thin-bedded 

sand and thin-bedded silt and silty sand. At many 

localities where the San Pedro overlies the Lomita a 

transition zone is marked by the gradual addition of 

i Reed R D , Petrology of the calcareous beds of San Pedro Hills, Calif, (abstract): 

Oeol Soc. America Bull., vol. 42, pp. 310-311,1931; Geology of California, pp. 259-260, 

.Am. Assoc. Petroleum Geologists, Tulsa, Okla., 1933. 

detrital material. . The petrology of the sand and gravel 

in the San Pedro has not been studied. For the most 

part these sediments consist apparently of granitic 

debris, derived presumably from granitic areas' north 

of the Los Angeles Basin. Some of the beds of gravel, 

however, contain pebbles of limestone, cherty shale, 

and schist, which are assumed to represent local debris 

derived from the Palos Verdes Hills. 

SE. 

TYPE REGION OF STRATIGEAPHIC UNITS 

The name "San Pedro beds" was used by Dall 8 in 

1898. It is not certain but is now immaterial whether 

the strata briefly described represent the San Pedro 

sand of this report, the Palos Verdes sand, or both. 

The term "lower San Pedro series" was used by the 

Arnolds, 9 for the San Pedro sand of this report. When 

the lower San Pedro series was named particular 

attention was devoted to exposures on Deadman 

Island. Localities along the San Pedro water front 

were mentioned, however, and that general region is 

regarded as the type region of the San Pedro sand. 

The strata assigned to the Timms Point silt were 

designated Pliocene by the Arnolds 10 and were assigned 

8 Dall, W. H., A table of the North American Tertiary horizons, correlated with 

one another and with those of western Europe, with annotations: U. S. Geol. Survey 

18th Ann. Rept., pt. 2, 335,1898. 

9 Arnold, Delos and Ralph, The marine Pliocene and Pleistocene stratigraphy 

of the coast of California: Jour. Geology, vol. 10, pp. 120, 124-126, 1902. Arnold, 

Ralph, The paleontology and stratigraphy of the marine Pliocene and Pleistocene of 

San Pedro, Calif.: California Acad. Sci. Mem., vol. 3, pp. 12,18-23,1903. 

10 Arnold, Ralph and Delos, op. cit., pp. 120,121-123. Arnold, Ralph, op cit. (Cali 

fornia Acad. Sci. Mem., vol. 3), pp. 12, 14-17, 1903.

y Crickmay u to the Santa Barbara formation. The 

name "Timms Point" as a stratigraphic term of forma 

tion or lower rank was proposed by Clark, 12 who desig 

nated Timms Point as the type region. 

The name "Lomita formation" has come into local 

usage and has been mentioned casually hi other printed 

reports. In this report the term "Lomita marl" is 

used and refers to the calcareous strata of the Palos 

Vcrdes Hills assigned to the lower Pleistocene. The 

type region is near Lomita quarry, in the western part 

of the Gaffey syncline. 

STRATIGRAPHY AND UTHOLOGY 

DEADMAN ISLAND 

Deadman Island, which is Reservation Point on the 

current edition of the Wilmington topographic map, 

was destroyed in 1928 to widen the channel to the innef 

harbor. The strata formerly exposed there are briefly 

described, as they played an important part hi early 

investigations. (See pi. 13, column 16.) 

The Timms Point silt (Arnold's Pliocene) dipping 

northeastward rested without marked discordance on 

the Malaga mudstone member of the Monterey shale, 

which was exposed at the south end of the island. The 

Timms point silt consisted of massive brownish sandy 

silt and silty sand locally cemented. At the base were 

pebbles of limestone and hard mudstone. According to 

Arnold's description. 13 the thickness was 20 to 45 feet, 

and the dip changed from about 25° at the base to 8° 

or 10° at the top. Crickmay 14 recognized six zones in 

the Timms Point silt (his Santa Barbara formation) 

representing a total thickness of 54 }£ feet. He found 

that northern fossils, including Patinopecten caurinus 

and Tfiyasira disjuncta, were most abundant hi zone 5, 

which was 25 feet thick, the base being 14% feet above 

the base of the member. Crickmay's zone 5 included 

Arnold's Cryptodon [Thyasira] bed. 

The San Pedro sand l5 overlaid the Timms Point 

silt along a sharp and irregular contact, as may be seen 

on Arnold's photographs. 18 It consisted of massive 

coarse-grained gray sand locally cemented. The sand 

dipped northeastward at about the same rate as the 

top of the Timms Point silt, 8° to 10°. Owing to the 

dip and unconformity along an almost horizontal plane 

at the top of the formation, the thickness increased 

from a maximum of 10 feet on the west side of the 

island to 20 feet on the east side. The basal 2 to 3 

feet contained limestone pebbles and cobbles as much 

as a foot long. Most of the cobbles were riddled with 

borings, and some had masses of the wormlike gastro 

pod Aletes sguamigerus attached to them. During the 

destruction of the island exceptionally well-preserved 

fossils were found on its east side at locality 30 in loose 

sand in the basal 6 feet of the formation. The fauna 

resembles that in the San Pedro sand hi San Pedro but 

includes some species of moderate-depth facies not 

found in San Pedro. At locality 30 fossils were scarce 

or absent more than 8 feet above the base of the 

formation. 

" Oriokman, 0. H., The anomalous stratigraphy of Deadman's Island, Calif.: Jour. 

Geology, vol. 37, p. 618,1929. 

" Clark, Alox, The cool-water Timrns Point Pleistocene horizon at San Pedro, 

Oallf.: San Diego Soc. Nat. History Trans., vol. 7, No. 4, p. 40,1931. 

" Arnold, Ralph, op. cit. (California Acad. Sci. Mom., vol. 3), p. 14,1903. 

« Orlckmay, 0. H., op. cit., pp. 622-627, table (p. 634). 

'«Arnold, Ralph, op. cit. (California Acad. Sci. Mem., vol. 3), p. 18,1903. Crick- 

may, 0. H., op. cit., pp. 628-630 (zone C). 

i« Arnold, Ralph, idem, pi. 25. 


TIMMS POINT 

The geology of the Timms area is shown on plate 14. 

Timms Point (pi. 15, B) is the type locality of the 

Timms Point silt. At that locality the Timms Point 

silt rests on the Malaga mudstone member of the 

Monterey shale (see pi. 13, column 15). The contact 

was formerly well exposed at the point but is now 

concealed by fill. It is exposed or is close to the sur 

face also at several localities on the east face of the 

bluff near the point. Bedding is not clearly discernible 

in the Miocene mudstone nor in the silt at the contact. 

At and near the point, the contact, which may conform . 

to the attitude of the Miocene mudstone, dips 30° 

northeastward, whereas on Harbor. Boulevard, 700 feet 

northwest of the point, the silt dips 14° northeastward 

near the contact. 

The Timms Point silt at Timms Point has been de 

scribed by Clark, 17 who recognized three units. The 

following section, in which the units are the same as 

dark's, was measured on the east face of the bluff: 

Section of Timms Point silt in type region at Timms Point 

3. Yellowish brown silty sand. Includes a layer con 

taining a few fossils, mostly Lucinoma anmdata, Ft. in. 

2 feet 8 inches above base..,____.___'_______-__- 16 0 

2. Yellowish brown silt and silty sand containing peb 

bles a few inches long of limestone and hard mud- 

stone and many shells__-__.____-________-_-- 2-6 

1. Yellowish brown silt, marly toward base. Contains 

scattered small pebbles of limestone and hard 

mudstone and generally a layer of pebbles at base. 

Pockets of silty calcareous sand at and near base 

contain many Foraminifera and small shells. 

Shells throughout, but scarce in upper 2 l/2 feet. 

Bryozoa locally abundant in lower part.-.-.-___ 14 0 

Maximum exposed thickness____.____..____ 30 6 

The estimated total thickness of the formation in 

this region is 70 feet. 

The sediments in the basal foot or two of unit 1 are 

somewhat calcareous, consisting of marly silt and 

pockets of silty calcareous sand. Foraminifera and 

small shells are particularly abundant in the more 

calcareous material (localities 32, 32b). About 150 

feet north of the point an almost pure concentrate of 

Foraminifera % to 2 inches thick rests on the Miocene. 

Foraminifera are rare above the basal 2 feet of the forma 

tion. Small shells and large shells, the latter including 

Patinopecten caurinus and fragments of Trachycardium 

guadragenarium, are abundant in unit 1 (localities 32a, 

32c). Bryozoa, particularly Idmonea californica, are 

locally abundant in the lower few feet near the point. 

Unit 2, not more than 6 niches thick, is characteiized 

by the abundance of pebbles. Fossils are less abundant 

than in unit 1 (localities 32d, 32e, 33). On the east side 

of Harbor Boulevard, 18 30 feet south of locality 33, unit 

2 rests directly on Miocene mudstone, the surface of 

which is probably irregular. Fossilif erous strata at local 

ity 34, on the west side of Harbor Boulevard, represent 

probably unit 2. The fossils include-an almost com 

plete Trachycardium guadragenarium and Pandora 

grandis. Poorly preserved fossils, including paired 

Thyasira disjuncta, a northern species, were found on 

the west side of Harbor Boulevard at locality 35, in 

strata higher than any exposed along the bluff. 

A retaining wall at the north end of the bluff conceals 

the strata for a distance of several hundred feet. North 

» Clark, Alex, the cool-water Timms Point Pleistocene horizon at San Pedro, 

Calif.: San Diego Soc. Nat. History Trans., vol. 7, No. 4, pp. 25-42, 2 flgs., 1931. 

is Since the current edition of the Wilmington topographic map was Issued Harbor 

Boulevard has been extended from the business district of San Pedro to Timms Point.

46 GEOLOGY AND PALEONTOLOGY OF PALOS VEBDES HILLS, CALIFORNIA 

of the retaining wall sand and silty sand assigned to the 

Sand Pedro sand form a low arch. Small specimens of 

Lucinoma annulata and Cerastoderma? were observed in 

a layer of silty sand. Even before the retaining wall 

was built Arnold 19 found the stratigraphic relations 

north of the bluff uncertain owing to inadequate ex 

posures, but his diagram, 20 which may have been drawn 

with the well-exposed Deadman Island section as a guide 

shows a discontinuity at the base of the sand. 

CENTRAL SAN PEDRO 

The most complete exposures of the lower Pleistocene 

strata in San Pedro are found in the central part of the 

town, between Pacific Avenue and Harbor Boulevard. 

In that area, and in no other so far as known, the three 

lithologic units are in superposition. The total esti 

mated thickness is about 350 feet. (See pi. 14.) 

At the base of the section are calcareous strata as 

signed to the Lomita marl, the computed thickness of 

which is about 100 feet. On Eighth Street, between 

Pacific and Mesa, the calcareous strata consist of fossil- 

iferous marl (locality 36). More extensive exposures of 

the marl were found at locality 37, in the alley north of 

Eighth Street. Fossils, including Bittium rugatum, 

Turritella cooperi, and Thracia trapezoides, are abundant 

at locality 37. Bedding was not recognized in the marl, 

but eastward toward Mesa Street, presumably upward 

in the section, the marl becomes siity. 

The most extensive exposures of the Lomita marl are 

on Second Street, between Pacific and Mesa (pi. 15, A; 

pi. 13,.column 14), where the strata dip northeastward 

at an angle of 22°. The following section was measured 

at that locality: 

Section of Lomita marl on south side of Second Street, between 

Pacific Avenue and Mesa Street 

Ft. in. 

4. Calcareous sand containing nodular masses of 

hard limestone of irregular shape. Overlain by 

Timms Point silt. For upward continuation of 

section see opposite column. 

b. Calcareous sand containing fewer and 

smaller limestone nodules than unit a 

(locality 42h, composite; locality 42i, 3 

feet below top)______________________ 6 10 

a. Calcareous sand containing many limestone 

nodules (locality 42f, 1 foot 

above base; locality 42g, 1% feet above 

base)_____________________________ 18 6 

3. Calcareous sand, marly calcareous sand, and marl 

containing coarse-grained calcareous material. 

c. Coarse-grained and fine-grained calcareous 

sand. A coarse-grained layer 10 inches 

thick at base and moderately coarsegrained 

layers throughout (locality 42d, 

coarse-grained layer at base; locality 

42e, 2 feet 10 inches above base) ______ 6 0 

b. Marl containing coarse-grained calcareous 

material-. ________________ ^ _________ 3 3 

a. Marly calcareous sand, basal 10 to 12 

inches cemented, forming nodular layer 

(locality 42c)___________________ 1 2 

2. Gray marl and calcareous sand. 

b. Gray marl (locality 42b)_______________ 7 9 

a. Gray calcareous sand (locality 42a)________ 5-11 

1. Gray marl containing pockets of marly calcareous 

sand (locality 42). Base not exposed_______ 5 2 

Maximum exposed thickness_____________ 49 7 

Marl like that in unit 1, presumably part of that 

unit, is exposed in an excavation along the alley south 

of Second Street. By tracing the nodular layer at the 

i° Arnold, Ralph, op. cit. (California Acad. Sci.Mem., vol. 3), p. 21,1903. 

"Idem, pi. 22, diagram D. 

base of unit 3 on the intervening hillside it is estimated 

that marl in the excavation extends 17 feet lower 

stratigraphically than the lowest exposures on the 

street, .making a total exposed thickness of about 66% 

feet. Unit 1 in both the excavation and on the street 

contains small and moderately large shells. Bittium 

rugatum and Turritella cooperi are abundant, and the 

fossils include fragments of the northern Thracia 

trapezoides. The fauna is the same as that in similar 

marl on Eighth Street and along the adjoining alley. 

The calcareous sand, and the marl that includes 

coarse-grained calcareous material contain small and 

young shells only or small shells, a few moderately 

large shells, and fragments of large shells, the last group 

consisting of Lucinoma annulata, Epilucina californica, 

and Macoma nasuta. The coarse-grained calcareous 

sand at the base of unit 3c (locality 42d), for example, 

contains only small and young shells. Turritella cooperi 

is abundant in that layer, but the specimens collected 

are minute tips. 

Exposures of the Timms Point silt were found on 

Eighth Street at and near Center (locality 38), where 

an almost complete large valve of the northern Pati- 

nopecten caurinus was collected near the top of the forma 

tion; on Mesa, near Seventh (locality 39); and on Third, 

near Mesa (locality 40). The computed thickness in 

this region, based on an assumption of an average dip 

of 12°, is 120 feet. The best exposures and the only 

locality where the contact with the underlying Lomita 

marl was observed are on Second Street (see pi. 15, A), 

where the formation is considerably thinner and dips 

northeastward 17° to 22°. A section measured on 

Second Street (pi. 13, column 14) is as follows: 

Section of Timms Point silt on Second Street, between Pacific Avenue 

and Mesa Street 

Ft. in. 

8. Massive yellowish-brown silty sand. Overlain by 

thin-bedded sand and silty sand assigned to San 

Pedro sand________________________________ 4 0 

7. Fossiliferous massive yellowish-brown silty sand 

(locality 45)_______________________________ 2 0 

6. Massive yellowish-brown sandy silt and silty sand, 

more sandy upward. Contains scattered fossils. 30 0 

5. Fossiliferous massive yellowish-brown sandy silt.- 1 2-5 

4. Massive yellowish-brown sandy silt_____________ 2 9-10 

3. Fossiliferous massive yellowish-brown sandy silt 

(locality 44a)-____-_________.______________ 6-9 

2. Massive yellowish-brown sandy silt_____________ 36 6 

1. Fossiliferous massive yellowish-brown sandy silt 

(locality 44). Rests on Lomita marl. Contact 

apparently slightly irregular but not sharp, 

lower few inches containing much calcareous 

material. For downward continuation of sec 

tion see opposite column ____________________ 7-8 

Maximum thickness. 78 2 

The subdivisions of the preceding section are based on 

fossiliferous zones, not on lithologic units. The entire 

formation consists of massive sandy silt and silty sand, 

sand increasing in abundance upward. The calcareous 

material at the base of the member is regarded as a 

transition zone to the underlying Lomita marl. It 

might be regarded, however, with equal plausibility as 

reworked material from the marl. The Timms Point 

fossils include northern species, notably Mitrella carinata 

gausapata, Patinopecten caurinus, My a truncata, and a 

small variety of Panomya beringianus. None of these 

species were found in the underlying Lomita marl in 

San Pedro, and with the exception of Patinopecten 

caurinus they were not found in the overlying San 

Pedro sand.

The base of the San Pedro sand is drawn arbitrarily at 

the base of the lowest bed of sand in a transition zone 

;about 30 feet thick consisting of thin-bedded sandy silt 

and silty sand. These strata dip northeastward 12° 

to 19°. The transition zone is exposed at the southeast 

corner of Eighth and Center Streets, on Fourth between 

Mesa and Center, at the southeast corner of Third and 

Mesa, and at the northwest corner of Second and Mesa 

(see pi. 13, column 14). At the last locality a few 

fossils were found in a bed of sand a few inches thick 

7% feet above the lowest bed of sand, which was selected 

as the base of the San Pedro sand (locality 46). These 

fossils represent an association like that at higher 

horizons in the San Pedro. 

The transition zone is overlain by apparently 

unfossiliferous cross-bedded sand. The thickness of 

the cross-bedded sand is difficult to estimate but is 

probably about 50 feet. It is exposed on Third Street 

near Palos Verdes, on First between Mesa and Center, 

on Center between First and Santa Cruz, 'and in the 

lower part of the bluff at Second and Beacon and nearby. 

It was described by Thompson, 21 who interpreted it as 

lower foreshore deposits superimposed on upper fore 

shore deposits. 

Bedded fossiliferous and unfossiliferous sand about 

20 feet thick overlies the cross-bedded sand. These 

strata, which dip gently northeastward, are well 

exposed at and near Second and Beacon Streets (pi. 15, 

GEOLOGY AND PALEONTOLOGY OP PALOS VERDES HILLS, CALIFORNIA 

At the Ancon and Beacon Street localities beds of 

silt are minutely crumpled, probably the result of 

submarine gliding down relatively steep slopes at the 

end of underlying lenses of sand. 

NORTHWESTERN SAN PEDRO 

In the northwestern part of San Pedro the lower 

Pleistocene strata consist almost entirely of sand and 

silty sand assigned to the San Pedro sand. The 

Lomita marl and Timms Point silt are absent or are 

so thin that they do not appear in natural exposures. 

The surface of the Miocene strata, on which the 

Pleistocene deposits rest, is evidently irregular. In a 

narrow ravine on the bluff opposite the end of Meyler 

Street Miocene mudstone and limestone are overlain 

by Pleistocene sandy silt in an exposure 15 feet long 

and a few feet wide. The limestone is riddled with 

bore holes, but no fossils were found in the overlying 

sandy silt. 

Cuts along the extension of Gaffey Street into San 

Pedro (not shown on current edition of Wilmington 

topographic map) furnish the .best exposures in the 

northwestern part of San Pedro. (See pi. 13, column 

13.) The contact with the underlying Malaga mud- 

stone member of the Monterey shale is exposed 125 feet 

north of the Elberon Street overpass. The basal 4 to 6 

feet of the Pleistocene strata, dipping 20° northeast 

ward, consists of marly silt containing Foraminifera, 

notably Cassidulina and Pyrgo. The marly sediments 

resemble those at the base of the Timms Point silt 

at Timms Point and may be assigned to that formation 

or to the Lomita marl. They are overlain by silty 

gray sand containing a few bored limestone pebbles. 

The next overlying strata consist of bluff silty sand 

and cleaner gray sand about 125 feet thick. A cross- 

bedded unit, shown on plate 15, D, consists of silty 

sand and is about 50 feet thick. Fossils were not 

observed in any of the sand or silty sand. 

Strata consisting chiefly of silty sand are exposed at 

intervals along the bluff at the north edge of San Pedro, 

east of Gaffey Street. At locality 48, opposite the end 

of Grand Street, fossils are abundant in a lens of clean 

gray sand overlying 3K feet of barren silty sand. The 

fossiliferous sand increases in thickness eastward to a 

maximum of 3 feet and where it is thickest includes 

stringers of barren sand. According to tlq.e regional 

strike, the fossiliferous sand at locality 48 is the equiva 

lent of the cross-bedded sand in the central part of San 

Pedro and, therefore, underlies the fossiliferous sand at 

Second and Harbor. 

EASTERN PART OF GAFFEY ANTICLINE 

Strata in the upper part of the San Pedro sand are 

exposed at intervals along Harbor Boulevard, north of 

San Pedro. In that area the formation is made up of 

sand, silty sand, and silt. The strata are gently folded 

on the flanks of the Gaffey anticline and the adjoining 

Gaffey syncline. A dip of 30° on the south flank of the 

anticline, in a ravine near Harbor Boulevard, represents 

presumably cross^bedding or slumping. The San Pedro 

sand is overlain normally by fossiliferous sand and 

gravel at the.base of the Palos Verdes sand. At some 

localities, however, the fossiliferous sand and gravel 

are absent, and the contact between the Palos Verdes 

and San Pedro is obscure, though it represents an 

unconformity. 

Fossiliferous cross-bedded sand at locality 49, oppo 

site the San Pedro Lumber Co. (not to be confused with 

Arnold's lumber yard locality in San Pedro), and inter- 

bedded sand and silty sand are assigned to the San 

Pedro sand. These beds are estimated to be as high 

stratigraphically as those at Second and Beacon Streets 

and may be higher. A section measured at locality 49 

is as follows: 

Section of San Pedro sand and Palos Verdes sand on Harbor Boule 

vard, opposite San Pedro Lumber Co. (locality 49) 

Palos Verdes sand: Ft. in. 

6. Gray silty sand containing few fossils-----.-.. . 8 6 

5. Fossiliferous gravel and coarse-grained sand (lo 

cality 120). Contact at base irregular_____- 2 7 

San Pedro sand: 

4. Gray silty sand, channeled by overlying gravel, 

which at places rests on unit 3___-_________ 2 6 

3. Cross-bedded fossiliferous gray sand (locality 

49a)______________-_.____--_--.-._____ 1 2 

2. Gray silty laminated sand___________________ 5 0 

1. Cross-bedded fossiliferous gray sand (locality 

49)--------__- T ---__---------_--_-_--_.- 1 0 

Exposed thickness of San Pedro sand.____ 9 8 

The entire preceding section may represent the'Palos 

Verdes sand instead of both the Palos Verdes and San 

Pedro. The collections from the sand assigned to the 

San Pedro include Cerithidea californica, Macron 

aethiops kellettii, and Cancellaria tritonidea. These 

species were not found in the San Pedro sand in the 

areas already described, whereas they are found in the 

Palos Verdes sand. Typical Palos Verdes species 

"Nassa" cerritensis, Crassinella branneri, Crassinella 

nuculiformis, Diplodonta sericata, and Trachycardium 

procerum were collected from the sand and gravel iden- 

.tified as the basal part of the Palos Verdes sand but not 

in the underlying cross-bedded sand identified as the San 

Pedro sand. The faunal evidence is not conclusive, 

however, for typical Palos Verdes species are absent 

farther west on the Gaffey anticline in a faunal facies 

interpreted as representing that formation. 

Fossils in a poor state of preservation, including 

Cancellaria tritonidea and large sand dollars (Den- 

draster}, occur in sand interbedded with silty sand 10K 

feet belo'w a fossiliferous sand identified as the base of 

the Palos Verdes along the siding of the Western Oil 

and Refining Co. (locality 50). A lenticular Ostrea- 

Anomia-Chione layer is in the San Pedro sand 5 feet 

above the sand containing^ the sand dollars. 

Along the valley followed by Gaffey Street and the 

Pacific Electric tracks the San Pedro sand consists of 

sand, some of which is cross-bedded, silty sand, and 

gravel (pi. 13, column 12). Locally sand and gravel 

are cemented, forming hard sandstone and conglom 

erate, probably along joints adjoining faults. A 

scour discontinuity is generally apparent at the base of 

gravel layers, as shown in the section on page 58. The 

gravel consists chiefly of granitic debris but includes 

also limestone, siliceous shale,. and rarely schist peb 

bles. The contact with the Miocene mudstone is 

exposed on the south side of a canyon, near the garbage 

disposal plant west of Gaffey Street. Fossils are not 

abundant in this region. A few species were collected 

from blocks of cemented sand and gravel discarded 

during excavation of sand at an abandoned sand pit on the 

west side of Gaffey Street (locality 51). Discontinuous 

Aeguipecten-Anomia and Ostrea-Chione layers were 

observed in gravel and sand on the east side of Gaffey 

Street, west of the tanks at the Union Oil Refinery. 

At locality 52, west of Gaffey Street, which was found

y Dr. Hampton Smith, Bryozoa and mollusks, includ 

ing a fragment of the northern Neptunea tabulata, were 

found in silty sand. The faunal and lithologic facies 

suggests the Timms Point silt. Pieces of large bones 

were observed at several places on the east side of 

Gaffey Street, and in that area Dr. Smith found a 

fragmentary mastodon tusk. 

HILLTOP QUARRY AND NEARBY LOCALITIES 

A.n abandoned quarry between Peck Park and the 

Standard Oil Co. tank farm is designated "Hilltop 

quarry" by geologists and local collectors. The quarry 

was recently filled during construction of a housing 

project. Calcareous strata in the Lomita marl were 

formerly excavated in this quarry. Figure 11 is a 

sketch of the southwest face of the quarry. The sand- 

filled fissures on the quarry face appear to mark the 

location of faults along which solution took place 

followed by filling of the fissures with the reddish-brown 

sand of the overlying nonmarine terrace cover. 

A bed 6 feet thick, composed chiefly of a loose mass 

of calcareous algae, is in the fault block on the quarry 

face and also at or near the level of the floor in the 

southern part of the quarry. An occasional mass of 

algae is cemented, particularly around pieces of 

Miocene(?) mudstone. The pieces of mudstone are as 

much as a foot long, and some are bored. A phospha- 

tized limestone boulder a foot long was dug out of the 

algal bed in the floor of the quarry. Large shells, in 

cluding Bursa califomica, Kelletia kelletii, Glycymeris 

pi'ofunda, Eucrassetella fluctuate, Cyclocardia aff. C. 

occidentalis, and Ventricolafordii, are scattered through 

the mass of algae. Many of the shells are encrusted 

with Bryozoa, and some have corals attached to them. 

Many pieces of algae are also encrusted with Bryozoa. 

Locality 53 represents the algal bed on the quarry face 

and locality 53a the algal bed on the floor near the west 

end of the quarry. 

The algal bed is overlain by gray marl. In the fault 

block on the southwest face of the quarry the contact 

between the two beds is irregular; elsewhere it is not 

exposed. Small shells are abundant in a 2-inch fossil- 

iferous lens 18 inches above the base of the marl on the 

southwest face (locality 53b). Toward the west a 

thickness of 14 feet of marl, including a bryozoan layer 

near the top, is exposed on the quarry face. On the 

northeast face of the quarry a gravel about 10 feet 

thick composed of limestone cobbles overlies marl, 

evidently the same bed as that on the south face. 

A more complete section of the Lomita marl is 

accessible in the canyon immediately west of the quarry 


(pi. 13, column 11). In the canyon the lower Pleisto 

cene strata rest on Miocene diatomite, but the contact 

is not well exposed. The section given below was 

measured with the collaboration of J. M. Hamill, 

B. G. Laiming, and R. D. Reed. The lowest Lomita 

strata, exposed in a pit on the canyon floor about 200 

feet downstream from the site of the loading hopper, 

are probably close to the base of the formation. By 

enlarging prospect pits on the east side of the canyon 

a continuous section was measured. 

Section of Lomita marl in canyon west of Hilltop quarry (locality 34) 

9. Gravel composed of loosely cemented limestone 

cobbles and pebbles in matrix of calcareous sand. 

Exposed on northeast face of Hilltop quarry. 

Thickness approximate. ____________________ 

Ft. 

10 

8. Light-gray marl. Thickness approximate. _.___. 10 

10 Feet 

FIGURE 11. Lomita marl on southwest face of Hilltop quarry. 

Section of Lomita marl'in canyon west of Hilltop quarry (locality 

64) Continued 

Ft. in. 

7. Coarse-grained calcareous sand and gravel. Large 

and small shells abundant, particularly in some 

gravel layers. Shells include Cyclocardia aff. C. 

occidentals, Eucrassatella fluctuata, and Ventri- 

cola-fordii. Corals, generally attached to peb 

bles or shells, more abundant in gravel layers 

than in any other part of section. (Locality 

54g.) 

d. Alternating layers of gravel and coarse 

grained calcareous sand containing scat 

tered pebbles. Contact at base of some 

gravel layers irregular. ' Shells abundant- 3 5 

c. Gray calcareous sand containing few pebbles...___......_.__________________ 

9 

b. Gravel consisting of pebbles in matrix of 

sandy marl. Contains abundant shells. 4 . 0 

a. Coarse-grained calcareous sand contain 

ing scattered shells.____.__.____-_--- 2 4 

6. Calcareous sand: 

d. Marly gray calcareous sand_...____---_- 7 6 

c. Marly gray and greenish calcareous sand 

containing small shells, including Cyclo 

cardia barber ensis, and broken' larger 

shells in upper greenish part (locality 

54f)__________________-________----_ 1 6 

b. Calcareous sand. Fine grained in upper 

part, coarse grained toward base; a few 

pebbles 2 to 3 inches above base. _____ 1 4 

a. Gray calcareous sand. Upper part fine 

grained, lower part coarse-grained glau- 

conitic, and foraminiferal. Echinoid 

spines abundant near base. Contains 

small shells and fragments of larger 

shells. Cyclocardia barbarensis abund 

ant (locality 54e). Contact at base 

irregular____________________________ 1 2-4


Section of Lomita marl in canyon west of Hilltop quarry (locality 

54} Continued 

. Ft. in 

5. Foraminiferal calcareous sand: 

d. Coarse-grained well-bedded yellowish cal 

careous sand containing scattered pebbles 

and a few small shells (locality 54d)______ 3 7 

c. Gray calcareous sand. Fine grained in up 

per part, coarse-grained layer at base. 

Small shells and a few larger shells mostly 

in lenticular pockets (locality 54c)_______ 2 

b. Yellowish calcareous sand, basal 2 inches of 

coarser grain than remainder. Contains 

abundant Foraminifera and a few small 

shells (locality 54b) _..--__--__-_-------- 1 

a. Gray foraminiferal calcareous sand_________ 2 

4. Gravel and coarse-grained calcareous sand: 

b. Coarse-grained calcareous sand containing 

pebbles of soft mudstone_______________ 

a. Gravel made up of pebbles of varying size in 

matrix of coarse-grained calcareous sand. 

Some pebbles are phosphatic. Contains 

small shells and fragments of larger shells 

(locality 54a)_________________________ 2 

3. Glauconitic foraminiferal sand containing scattered 

pebbles and limy phosphatic nodules. Con 

tains abundant Foraminifera and a few small 

shells, including Cyclocardia barbarensis (locality 

54).___.___'_. r ..__.._._.___ --_--_-__--_-- 

'2. Gravel consisting of pebbles and cobbles in matrix 

of glauconitic foraminiferal sand. Pebbles and 

cobbles of varying .size, one limestone cobble 16 

1 

inches long, and small limy phosphatic nodules. 

Contains a few small shells, mostly Cyclocardia. 

Glauconitic sand, foraminiferal and lighter in color 

toward top. Base not exposed.___-__-___-__ 3 6-10 

8 

0 

1 9-11 

Thickness of section___.._____-_-_______-__ 60 11 

The gravel at the top of the preceding section is ex 

posed on the northeast face of the quarry. It overlies 

marl that rests evidently on the algal bed. The coarse 

:grained calcareous sand and gravel forming unit 7 of the 

canyon section appears to correspond, therefore, in 

stratigraphic position to the algal bed and grades south 

ward presumably into the algal bed. Faunally unit 7 

is more similar to the algal bed than any other unit in 

the canyon section. It, is, however, thicker than the 

algal bed, contains far less calcareous algae, and in 

cludes more coarse detrital material. The algal bed is 

evidently a local feature of small extent, at least across 

the strike and possibly also along the strike. Forami 

nifera occur throughout the canyon section, except in the 

gravel at the top. They are particularly abundant in 

some layers of calcareous sand, notably in units 6a (pi. 

16) and 5b, and in the glauconitic sand forming units 3, 

2, and 1. Turritella pearoensis is more abundant in 

calcareous sand exposed in a pit on the west side of the 

canyon (locality 55) than in any bed on the east side of 

the canyon or in the quarry. 

Northwest of Hilltop quarry the Lomita marl is ex 

posed at localities on the flanks of the Gaffey syncline. 

In natural exposures and in long-abandoned prospect 

pits it consists generally of hard limestone or calcareous 

sandstone containing calcareous 'algae, encrusting 

Brypzoa, and other calcareous organisms. Localty 

fossils are not discernible, owing to leaching and dep 

osition of secondary calcareous material. Limestone 

cobbles at or near the base of the formation are generally 

riddled with the burrows of boring clams, some of which 

are preserved in their burrows. 

The basal part of the lower Pleistocene strata on the 

north flank of the Gaffey syncline is well shown in a cut 

on Western Avenue. The lowermost 5 feet, assigned to 

the Lomita marl, consists of a mixture of sand and cal 

careous sand containing calcareous algae, shell frag 

ments, and bored angular and rounded limestone 

pebbles. These calcareous sediments dip 30° south 

ward and rest on Miocene mudstone of the Malaga 

member of the Monterey shale that appears to dip 

southward at a low angle. They grade upward into the 

San Pedro sand, at the base of which is about 10 feet of 

silty sand containing small shells and shell fragments. 

The silty sand in turn grades upward into partly 

cemented gray sand overlain by cross-bedded limonite- 

stained gray sand. As shown on plate 17, B, the lower 

Pleistocene deposits and the overlying terrace cover are 

displaced by a minor bedding-plane thrust fault along 

the contact between the Miocene and Pleistocene 

strata. 

, At Hilltop quarry and in the area to the northwest 

the San Pedro sand overlies the Lomita marl. Locally 

sand appears to extend down to the base of the Pleis 

tocene section; at least locally no outcrops of the 

Lomita marl were found. The sand is generally poorly 

exposed. In an excavation on the Standard Oil Co. 

tank farm, gray sand, assigned to the San Pedro, con 

tains fragile shells (locality 56). On the south flank of 

the Gaffey syncline a cut on Western Avenue exposes 

about 15 feet of sand and gravel considered ofJSan Pedro 

age. A collection of fossils from gray sand~at the base 

of the cut on the east side of the highway includes frag 

ments of Neptunea tabulata (locality 58). This sand is 

overlain along an irregular contact by cross-bedded 

sand, at the base of which is gravel consisting of lime 

stone and schist pebbles. The cross-bedded sand is as 

much as 10 feet thick and contains numerous specimens 

of Anomia and Ostrea (locality 58a). An Anomia- 

Ostrea layer in a natural outcrop of cemented sand 

nearby, locality 59, is doubtless' the same layer. A 

fossiliferous gravel overlying the Anomia-Ostrea layer in 

the highway cut is selected as the base of the Palos 

Verdes sand. The contact between the two formations 

might, however, be placed at the base of the Anomia- 

Ostrea layer, which represents an association like that in 

strata assigned to the Palos Verdes sand on the north 

limb of the Gaffey syncline. 

The Whites Point tunnel penetrated the lower 

Pleistocene deposits on the flanks of the Gaffey anti 

cline and Gaffey syncline (pi. 1, section E E' ; pi. 

13, columns 8, 9, 10). On the north flank of the anti 

cline the San Pedro sand, about 275 feet thick, rests 

directly on the' Malaga mudstone member of the 

Monterey shale, as at the outcrop nearby. It consists 

of regularly .bedded sand, crossbedded sand, and thin 

layers of silt and clay. Throughout a considerable 

thickness layers of sand contain glauconite, a con 

stituent not observed at outcrop localities. On the 

south flank of the anticline 15 feet of silty marl rep 

resents the Lomita marl. The marl grades upward 

into the San Pedro sand, which includes glauconitic 

sand. On the south limb of the Gaffey syncline the 

Lomita marl is about 275 feet thick and rests with 

marked unconformity on Miocene diatomaceous shale 

and diatomite. At the base is gravel 25 feet thick 

composed of limestone cobbles and angular pieces of 

shale. The conglomerate is overlain by fossiliferous 

marl and silty marl grading upward into sandy marl. 

The overlying San Pedro sand consists of gravel over 

lain by sand and silt. A total thickness of about 175 

feet of strata assigned to the San P(edro sand was 

penetrated, and an estimated additional thickness' of 

125 feet is represented in 'the trough of the syncline. 

The tunnel shaft on the south limb of the syncline 

penetrated the Lomita marl. Well-preserved fossils,


A. VIEW \K\K .NORTH KM) OF MALAGA COVE. 

For explanation see B. 

B. VIEW 200 FEET SOUTH OF A. 

a, Dune sand (Recent); b, nonmarine cover of lowest terrace (upper Pleistocene to Recent); c, San 

Pedro (?) sand (lower (?) Pleistocene); d, massive radiolarian mudstone, Malaga mudstone member 

of Monterey shale (upper Miocene); e, laminated diatomite, Malaga mudstone member of Monterey 

shale (upper Miocene). 

C. REPETTO SILTSTOJNE (LOWER PLIOCENE) ON SOUTH LIMB OF 

NORTHERN SYNCLINE. 

Arrow points to lower bed of volcanic ash. Note seated men at foot of cliff, which is 150 feet 

high. 

MIOCENE, PLIOCENE, AND PLEISTOCENE FORMATIONS AT MALAGA .COVE.


NW. 

YORTH BORDER OF HILLS 

MALAGA. COVE 

gg;g:-:;g:5:J:-:g;:; 

. Malaga mudstone 

member of Monterey shale 

(upper Miocene) 

1 

9 

SOUTH1 

FLANK OF GAFFEY ANT CLINE, 

SUBSURFACE SECTION 

WHITES POINT TUNNEL i 

î=?^+zm 

Malaga mudstone 



Nonmarjne cover 

of first terrace 

San Pedro(?)sand 

San Pedrosand 

lomrla marl 

2 

tJORTH 

BORDER OF HILLS, 

FIFTH RAVINE WEST OF 

HAWTHORNE AVENUE 

'. '. '. '.-.' ' ' ' ' ' '. '. ' ' '. ' ' ' ' '. Nonmarine cover 

.... .-. . . /? ' . . of first terrace! 

.'.'.V.V/. '.'.'.'.'.'.'.'.'.'.'.' 

' -U r±=^ cj^f^^^r.:- 

Faulted against 

Malaga" mudstone 


10 

i 


San Pedro sand NORTH BORDER OF HILLS 

EAST SIDE OF AGUA 

NEGRA CANYON 

Lomita marl 

SOUTH FLANK OF GAFFEY SYNCLINE,. 

SUBSURFACE SECTION 

WHITES POINT TUNNEL ', 

mttmtm 

. :-:-:'-:-:::-:v: :: :x--:: ::':'---> 

^r^-î.^ v-L-.-.-.- 

.Xvlv/X* .*.*.*.*' . . '. '.'. '/.'. 

I'M'I ', '. ' . '. '. ' * ' '.-I-''*' '. 

^^fS^/fiM^ 

^L^l^îVfi/fr 

'/rr;'..'.'f? '.'.-T^.' : '^ ^frr'^: 

-^^r^S^S 

-^Zi-t^-Ii^ ' '==' 

-jJ-Z-L^r1 -r1 -r^ 

-^-.-t.^'^-TP.-r 

^^'^.^^r: 

*'.'* '.: v". . * *** ft Iv J J I- T- 

^ '. i'X'M'!-*'"."Vr'rvi-i-"*'*'-' 

Altamira shale member 

of Monterey shale 

'middle Miocene) 

San Pedro sand 

Lomita marl 

3 

rl^'Tvri-Jv/x'iAd-r.-v:-'. 

5St!Ît£.^f: 

*^&&4?tW*&&J 

Valmonte diatomite 

member of Monterey shale, 

(.upper Miocene) 

11 

, 

Nonmarine cover 



Lomita marl 

CANYON WEST OF 

HILLTOP QUARRY ! 

. . . . . . - . . . . . . . . . .-. . San Pedro 

'\-i\-X\-X-X-X .' ." .' ' .' .' .' sand 

Unexposed^ 

4^:-^4S !x54filip: 7 

"a- .-" ' >- -t.» c Lomita marl 

-^xSSV^ ' =^(54* » 

^^z^xsaa £§3c 5^ 

^-.xSAJj.-jtSAaTA.^^ ^4 

:r-:-:r.-:-:r.v:r..:-:i?f?i?>.:.:^2 3 

Unexposed 

" 

4 

NORTH BORDER OF HILLS, 

0.2 MILE SOUTHEAST OF 

CRENSHAW BOULEVARD 



Unexposed 

Unexposed 

12 

WEST SIDE OF GAFFEY 

STREET NEAR CREST 

OF GAFFEY ANTICLINE 

'.Vila?: ; . : : : : . : : :-; ; 

-. vlvX-lv.'v'.- '.-'. ; -X-lv 

: : : :x: -':-- ::::'-x^?f!':-::?:: 

Unexposed 



i 





6 

5 

MORTH FLANK OF GAFFEY 

MORTH FLANK OF GAFFES r 

ANTICLINE, SIDEBOTHAM 

ANTICLINE, SIDEBOTHAM 

MO. 2 SAND PIT, EAST SIDE 

NO. 1 SAND PIT, WEST SIC )E ( DF BENT SPRING CANYON 

DF BENT SPRING CANYON 

.'X'XX-X.'XvX'XvX'X Nonmarine cover 

I Nonmarine cover iXvXX.-'.v.X-XvX.vXv of first terrace 

of first terrace vl-lvX v! »'. /. ';';';' Palos Verdes sand 

'*$$££$.$£& 




13 

GAFFEY STREET, 

SAN PEDRO 

iSSSSSS^SSi-x? 

:W/:S:':SS^:"'::-1 J' 

' £:-^^Z±-f:-777. ' :' 

Altamira shale membef Malaga mudstone 

« Monterey shale member of Monterey shale 

luppef Miocene I (upper Miocene) 

San Pedrp sand 




limms Point silt 

'or Lomita marl 

50 50 .250 Feet 

SECTIONS OF PLEISTOCENE STRATA IN PALOS VERDES HELLS. 

:;:;:;>§:i:j:;:^ggri:i: 




M 

SECOND STREET, 

SAN PEDRO 

Unexposed 

X-x-x*47e:-.x-xx-x-x 

:'-::'.v: : : : :-:'-:'-x ::^*?f: :::': : : 

-.-. . - _ - . . . . . . .-. . .-. . 

'.' [ .' Wp^-.'^T^-v'/. ! ;'.' .' 

^7^=T^J?


A. NORTH SIDE OF SECOND STREET IN BLOCK BETWEEN PACIFIC AVENUE AND 

MESA STREET. 

Loinita marl (c) conformably overlain by Tiinms Point silt (b). Both formations unconformably 

overlain by Palos Verdes sand and nonmarine terrace cover (a). 

C. SAN PEDHO SAND (b) UNCONFORMABLY OVERLAIN BY PALOS VERDFS SAND 

AND NONMARINE TERRACE COVER (a) AT SOUTHWEST CORNER OF SECOND 

AND BEACON STREETS. 

PLEISTOCENE FORMATIONS IN SAN PEDRO. 

B. TIMMS POINT SILT IN TYPE REGION AT TIMMS POINT. 

D. CROSS-BEDDED SAND IN SAN PEDRO SAND ON EAST SIDE OF GAFFEY STREET. 

Photograph by U. S. Grant.

GEOLOGICAL SUBVEY PROFESSIONAL PAPER 207 PLATE 16 

MICROSCOPIC ORGANIC CONSTITUENTS IN UNIT 6a OF LOMITA MARL IN CANYON WEST OF HILLTOP QUARRY. 

Unsorted washed residue, a, Globigerina; b, Cassidulina; c, Potymorphina; d, Dentalina; e, Pyrgo; f, Cyclocardia; g, Cadulus?; h, echinoid spine.

including numerous specimens of Bittium rugatum, 

Turritella, pedroensis, Olivella biplicata, Conus califor- 

nicus, and Cyclocardia aff. C. occidentalis, were collected 

from the dump at the shaft (locality 57). 

10 MIT A QUARRY AND NEARBY IOCAIITIES 

Thq type region of the Lomita marl is in the area 

near Lomita quarry in the western part of the Gaffey 

synclinc. In that a,rca.the Lomita overlies the Repetto 

silts tone or overlaps the Repetto and rests on the 

Malaga mudstonc member of the Monterey shale. At 

the localities where the base of the Lomita is well 

exposed in the ravine northeast of Lomita quarry 

and along the road leading to the quarry the under 

lying formation is the Repetto. Toward the north, 

that is, toward the crest of the Gaffey anticline, the 

calcareous strata appear to finger into sand, but there 

are no excavations to show that relationship. The 

greatest exposed thickness of the Lomita is about 65 

foot, but core holes in the syncline are reported to 

have penetrated a thickness of 300 feet. A section 

measured at Lomita quarry (pi. 17, A; pi. 13, column 

7), on the north limb of the syncline, is as follows: 

Section of Lomila marl in type region at Lomita quarry [locality 6S) 

Ft. 

4 

Nonmarine terrace cover(?): Coarse-grained brownish 

sand, grading upward into dirty brownish 

sand _ .--___-___-_.___-_ _--_-._...__.._____ 6 

San Pcdro(?) sand: 

Gravel, consisting principally of small granitic 

pebbles. . -.--_----------_--.--_--__-_____ 2 

Cross-bedded gray limonite-stained sand including 

lenses of gravel consisting principally 

of small granitic pebbles. _ _________________ 18 

Lomita marl: 

7. Fine-grained calcareous sand and foraminif- 

eral calcareous sand including partings of 

glauconitic foraminiferal sand___________ 8 3 

6. Glauconitic formainiferal sand: 

b. Glauconitic foraminiferal sand lighter 

5. 

1. 

a. 

in color than unit a_______________. 8 

Dark-colored glauconitic foraminiferal 

sand containing scattered shells, 

principally Cyclocardia barbarensis 

(locality 62b)____.._____________ 10 

Foraminiferal calcareous sand and glauco 

nitic foraminiferal sand in layers 2 to 6 

inches thick (locality 62a)_-_________---_ 10 7 

Fine-grained calcareous sand and foraminif 

eral calcareous sand. Contains boulders 

of Miocene Malaga mudstone and of Plio 

cene Repetto siltstone in lower 9 feet, one 

boulder measuring 12 by 5 feet, and scat 

tered limy phosphatic nodules.._________ 21 10 

Glauconitic sand_-________--_____________ 11 

Foraminiferal calcareous sand containing 

scattered glauconite grains (locality 62). 

Base not exposed_____________________ 9 

Poorly exposed calcareous strata. In the 

ravine northwest of the quarry they rest 

on the lower Pliocene Repetto siltstone and 

contain limy phosphatic nodules. Thick 

ness coinputed__----_-__--__---_------- 20 0 

Thickness of Lomita marl.____________ 63 10 

The glauconitic foraminifei;al sand forming unit 6 of 

the preceding section can be traced as a dark-colored 

band across the quarry face. (See pi. 17, A) It shows 

many minor faults, along which the displacement is 

down toward the \vest. The huge boulders in unit 4 

consist of both Miocene mudstone and Pliocene silt- 

stone. As both kinds of rock readily disintegrate in 

water, the boulders were preserved probably by sinking 


m. 

0 

into soft calcareous sand. .Foraminifera from the 

Lomita marl at Lomita quarry were described by 

Galloway and Wissler. 24 Mollusks are not abundant. 

A collection from unit 6 (locality 62b) includes frag 

ments of Patinopecten caurinusf, but Cyclocardia 

barbarensis is the most common species, as it is in other 

mollusk-bearing layers. 

Parts of the Lomita marl are exposed in prospect 

excavations southeast of the quarry. At locality 61 

a bed of gravel and coarse-grained calcareous sand, 

evidently higher in the section than the strata in the 

quarry, contains large shells of shallower facies than 

those in the quarry, including Turritella pedroensis, 

Ostrea mcgodon cerrosensis, and ventricola jordii. Most 

of the shells are worn and broken. The following 

section was measured in a prospect excavation at 

locality 60, near the trough of the Gaffey syncline, 

500 feet west of Palos Verdes Drive East: 

Section of Lomita marl in prospect excavation 500 feet west of Palos 

Verdes Drive East (locality 60) 

Ft. 

18. Foraminiferal calcareous sand, grading upward 

into soil. Thickness approximate ___________ 4 

17. Coarse-grained calcareous sand.___-____-___-__ 

16. Foraminiferal calcareous sand-___________ _____ 1 

15. Coarse-grained calcareous sand___.__.-______-- 1 

14. Foraminiferal calcareous sand-________________ , 1 

13. Glauconitic foraminiferal calcareous sand. Cross- 

bedded at base, 3-inch dark layer at top. Base 

extremely irregular (locality 60b)_----_------ 11-19' 

12. Foraminiferal calcareous sand and glauconitic 

sand: 

c. Foraminiferal calcareous sand. One angu 

lar pebble" observed. _ _________________ 16-22 

b. Glauconitic sand. ____________________ 1 

a. Foraminiferal calcareous sand_____.--_- 8-10 

11. Fine-grained calcareous sand________________ 2-3 

10. Glauconitic sand and foraminiferal calcareous 

sand: 

b. Glauconitic foraminiferal calcareous sand 

containing scattered pebbles. ___________ 7 

a. Foraminiferal sand.__________________ 1 1 

9. Coarse-grained calcareous sand containing many 

pebbles, including a 5-inch pebble standing on 

end and projecting above top of bed...------ 4-5- 

8. Foraminiferal calcareous sand, including a half 

inch parting of glauconitic foraminiferal sand 

at middle. _---_--------__----_-___------- 1 0' 


rounded and angular pebbles, broken large 

shells, and small shells (locality 60a)--------- 5 

6. Foraminiferal calcareous sand.__-__-__-----!--- 4-6- 

5. Coarse-grained calcareous sand.____----------- 7 

4. Foraminiferal calcareous sand (locality 60). _ . _ _ 5 


calcareous algae and Bryozoa and scattered 

limy phosphatic nodules. One 8-inch pebble 

extends above top of ;bed_____-_--_--------- 1 2' 

2. Fine-grained glauconitic, foraminiferal sand _ . - - - 5 


calcareous algae and Bryozoa. Base not ex 

posed. ___.___-_______..-__--_-_----------- 10 + 

Exposed thickness._-__-_-_------.------- 20 2 

The contact at the base of most of the main units in 

the preceding section is sharply defined and slightly 

irregular. The base of unit 13 is very irregular, forming 

angular gutters 5 to 7 inches deep. The glauconitic 

sand filling the gutters and extending above them is 

cross-laminated.. Foraminifera are more abundant at 

this locality in foraminiferal calcareous sand and in 

glauconitic sand than at Lomita quarry. The coarse 

grained pebbly calcareous sand forming unit 7 contain s. 

broken large shells and small shells (locality 60a). 

'« Galloway, J. J., and Wissler, S. O., Pleistocene Foraminifera from Lomita quarry 

Palos Verdes Hills, Calif.: Jour. Paleontology, vol. 1, pp. 35-87, pis. 7-12,1927.


The sand and gravel overlying the Lomita marl at 

Lomita quarry are assigned doubtfully to the San 

Pedro sand. (See section above.) At the time when the 

Lomita quarry section was measured the sand and gravel 

were excavated back from the quarry face, and the re 

lations were not clear. From the view on plate 17, A, 

which was taken soon after the quarry was opened 

many years ago, it appears that the sand and gravel un- 

conformably overlie the Lomita. They are similar 

lithologically to deposits in the San Pedro sand as iden 

tified nearby on the north limb of the Gaffey anticline. 

It is improbable that they represent either the Palos 

Verd6s sand or the nonmarine terrace cover. Strata 

identified as the Palos Verdes sand at locality 136 are 

thinner and contain limestone cobbles. The nonmarine 

cover in this region is not known to be so thick or to 

include clean sand and granitic gravel. Sand and gravel 

similar to those at Lomita quarry are exposed in the 

upper part of the 'ravine northwest of the quarry. At 

locality 63 silty sand contains Bryozoa, worn opercula of 

Homalopoma, and pelecypod fragments including Cy- 

clocardia. . Mudstone at the level of the ravine floor 

may represent a boulder or outcrop of the Miocene. 

According to. the interpretation suggested, the San 

Pedro sand appears to overlie unconformably the Lo 

mita marl in the western part of the Gaffey syncline. 

WESTERN PART OF GAFFEY ANTICLINE 

Outcrops of calcareous strata referable to the Lomita 

marl were found on the north flank of the Gaffey 

anticline, along the ravine followed by Palos Verdes 

Drive East and in the next two ravines to the east. 

The calcareous strata, consisting of calcareous sand 

generally cemented, are only a few feet thick. They rest 

on the Repetto siltstone or Malaga mudstone. In 

the easternmost ravine, where the calcareous sediments 

are 6 feet thick, the contact with the Malaga mudstone 

is well exposed. 

At the localities just mentioned the San Pedro sand, 

which is not well exposed, overlies the Lomita marl. 

Along Bent Spring Canyon, northeast of Lomita quarry, 

the sand rests directly on the Malaga mudstone. The 

contact is plainly exposed at the loading hopper of 

Sidebotham No. 2 sand pit on the east side of the 

canyon (pi. 18,^) and along the road leading to 

Lomita quarry on the west side. At the loading hopper 

the lowermost 11 feet consist of silty sand, including 

lenses of gravel. The silty sand is overlain by coarse 

grained sand and gravel. Between the loading hopper 

and the water tank the basal silty sand contains a 

Lomita-like fauna of moderate-depth facies (locality 

64). Coarse-grained sand and gravel overlie the silty 

sand with a sharp contact, but the silty sand itself 

includes lenses of coarse-grained sand and gravel. 

Fossils similar to those at locality 64 were observed 

in the basal part of the sand on the west side of the 

canyon. 

Sidebotham No. 1 pit (pi. 13, column 5; pi. 19), on 

the west side of the canyon, shows about 100 feet of 

sand and interbedded layers and lenses of gravel 

dipping gently northward. The sand is gray or 

limonite-stained and includes thin cross-bedded units. 

No. 2 pit (pi. 13, column 6; pi. 18, B] shows steeply 

dipping sand and gravel overlain by gently dipping 

sand and gravel. The gravel in both pits consists 

chiefly of granitic debris but includes limestone and 

cherty shale pebbles. At the top of the west face of 

No. 1 pit, immediately underlying the nonmarine 

terrace cover shown on plate 18, Bryozoa and Lomita- 

like mollusks of moderate-depth facies were found in 

a 21-inch lens of marly, silty sand (locality 65). Uni 

dentifiable broken organic calcareous particles were 

observed in a 2-inch layer of sand and gravel in the 

steeply dipping strata at the south edge of No. 2 pit. 

The stratigraphic and chronologic relations of the 

sand and gravel in this area may be interpreted in 

different ways. These deposits are assigned to the 

San Pedro sand. Most or perhaps all of the section 

is doubtless the detrital equivalent of the Lomita marl. 

On the west side of the canyon fossils resembling in 

facies those found at places in the Lomita occur at 

the bottom and top of the section. Inasmuch, however, 

as fossils of similar facies occur at places in the San 

Pedro, the faunal data are inconclusive. The section 

in No. 2 pit may represent two stratigraphic units or 

the steeply dipping strata may represent a thick cross- 

bedded unit. It may be argued that the deposits of 

steeply dipping sand and gravel in No. 2 pit are the 

equivalent of the Lomita, whereas the gently dipping 

sand and gravel are the equivalent of similar deposits 

that appear to be unconformable on the Lomita at 

Lomita quarry. 

NORTH BORDER:OFLHIIIS BETWEEN BENT SPRING CANYON AND 

HAWTHORNE AVENUE 

The sand and gravel in ravines along the north border 

of the hills between Bent Spring- Canyon, and Agua 

Magna Canyon, except a thin cover of nonmarine terrace 

material, are assigned to the San Pedro sand. These 

San Pedro strata consist of brownish sand and gray 

limonite-stained sand, both containing stringers of gra 

nitic gravel. Toward the top small limestone and cherty 

shale pebbles are abundant in the gravel stringers. The 

Palos Verdes sand is not identified in this area. The 

uppermost few feet, consisting of reddish-brown sand, 

is assigned to the nonmarine terrace cover, but no' 

sharp contact with the underlying deposits was recog 

nized. Fossils, including Mitrella carinata gausapata, 

a large broken Patinopecten caurinus, My a truncata, a 

small variety of Panomya beringianus, Foraminifera, 

and Bryozoa, were collected from silty sand in a ravine 

at locality 66 (pi. 13, column 4). On lithologic and 

faunal grounds the strata at locality 66 are referred to 

the Timms Point silt, the only locality in the western 

part of the hills where that formation was found. Ex 

posures are inadequate at locality 66, but the silty beds 

are evidently at or near the base of the section and are 

overlain by sand. Sand, containing stringers of gravel 

consisting chiefly of small limestone and cherty shale 

pebbles, and silty sand in the two sand pits east of Agua 

Negra Canyon are assigned to the San Pedro sand. Lay 

ers of sand in the eastern pit contain Foraminifera and 

pieces of Bryozoa and shells. 

On the east side of Agua Negra Canyon the Lomita 

marl is represented by marl and gravel. (See pi. 13, 

column 3.) At the level of the canyon floor rubble and 

boulders of limestone and cherty shale abut against an 

ancient cliff face of Miocene mudstone (fig. 12). On 

the north face" of the' northernmost cut in the workings 

of the Dicalite Co. near Agua Negra Canyon the marl 

rests on Miocene diatomite. A few limestone cobbles 

are at the base of the marl, and a thick gravel composed 

of limestone cobbles is 30 to 35 feet above the base, 

underlying fossiliferous gravel and sand of the Palos 

Verdes sand. Farther north the Lomita marl is esti 

mated to be about 75 feet thick. It includes beds of

gravel as much as 20 feet thick made up of limestone 

cobbles. Fossils are abundant in the marl, particularly 

Bittium rugatum and Turritella pedroensis (localities 

67, 68). ' 

Miocene diatomite is exposed at the southeast edge of 

Richard Ball sand pit, immediately east of Hawthorne 

Avenue. Steeply dipping marl of the Lomita 10 to 15 

foot thick rests on the diatomite, a fossiliferous gravel 2 

or 3 feet thick being at the base. The marl gradually 

becomes more and more sandy toward the top and is 

FIOURE 12. Contact between Lomita marl and Miocene mudstone on east bank of 

Agua Ncgra Canyon. 

overlain by about 60 feet of sand and gravel assigned 

to the San Pedro sand. (See pi. 20, A.) Though the 

dip changes from 55° in the marl to 25° in the upper 

part of the sand, the change is gradual, and there ap 

pears to be no unconformity. 

On the 461-foot hill south of the sand pit the thin 

cover of nonmarine terrace deposits has been stripped 

off, revealing the Lomita marl and at places the under 

lying Miocene diatomite. Fossils collected from the 

marl include broken specimens of Eucrassatella fluc- 

tuata and Mercenaria perlaminosa (locality 69). 

NORTH BORDER OF HILLS BETWEEN HAWTHORNE AVENUE AND MALAGA 

COVE 

Steeply dipping lower Pleistocene strata similar to 

those just described are exposed in ravines northwest 

of Hawthorne Avenue. The geology of the area adjoin 

ing Hawthorne Avenue is shown on plate 21. The 

lower Pleistocene deposits overlie Miocene mudstone 

NE. 


gravel composed of limestone cobbles. The marl 

grades upward into the San Pedro sand, which includes 

layers of gravel. The dip of the sand is gradually less 

upward in the section. Plate 20, B, shows the succes 

sion in a sand pit on the west side of the fourth ravine 

west of Hawthorne Avenue. At that locality there is 

a minor fault between the sandy marl and the sand. 

The strata exposed in the fifth ravine west of Haw 

thorne Avenue are shown in figure 13 and on plate 13, 

column 2. Fossils occur in the Lomita marl, Turritella 

pedroensis being generally abundant (localities 70, 71, 

72, 72a, 73, 73b). They are rare in the San Pedro sand 

(locality 73a). 

MALAGA COVE 

At the north end of Malaga Cove, sand and gravel 

about 75 feet thick unconformably overlie the Malaga 

mudstone member of the Monterey shale (pi. 12, A, B; 

pi. 13, column 1; fig. 7). The dip of the sand and 

gravel changes gradually from 13° at the base to about 

8° near the top. The sand is clean and gray or limonite- 

stained. The gravel is made up chiefly of granitic 

debris, but the largest pebbles, 2 to 4 inches^long, con 

sist of cherty shale. A few Foraminifera were found in 

a 3-inch layer of sand 7 feet-above the base of the sand 

on the upthrown side of the bedding-plane fault shown 

on plate 12, A (locality 74). The sand and gravel at 

Malaga Cove are assigned doubtfully to the San Pedro. 

Assignment to the San Pedro sand rather than to the 

Palos Verdes sand is based on the lithology, which 

agrees with that of deposits identified as the San Pedro 

to the east. If the Foraminifera at locality 74 are not 

detrital constituents, they also favor assignment to the 

San Pedro. Reddish-brown sand 15 to 25 feet thick 

near the top of the cliff is identified as the nonmarine 

terrace cover. The contact with the underlying San 

Pedro (?) sand, however, is generally not well defined. 

MARINE TERRACE DEPOSITS 


The marine terraces are described under the heading 

"Physiography"" (p. 113), and then- distribution and 

designation are shown on plate 22. They are desig- 

FIOUHK 13. Pleistocene strata in fifth ravine west of Hawthorne Avenue, a, Nonmarine terrace cover (upper Pleistocene to Recent); b, Palos Verdes sand (upper 

Pleistocene); c, San Pedro sand (lower Pleistocene); d, Lomita marl (lower Pleistocene); e, Malaga mudstone member of Monterey shale (upper Miocene). 

or diatomite, except at the head of the fourth ravine 

west of Hawthorne Avenue where the underlying for 

mation is the Repetto siltstone. Fossiliferous sandy 

marl of variable thickness at the base of the lower 

Pleistocene deposits represents the Lomita marl. At 

the base of the marl are scattered limestone cobbles or 

nated in numerical sequence in reverse age order, the 

first terrace being the youngest and lowest, the last to 

be formed. 

Deposits lying on the terraces embrace material of 

two classes marine sand and gravel and nonmarine 

debris designated the nonmarine cover. The marine


deposits consist generally of cleanly washed, poorly 

sorted stratified .coarse-grained sand and gravel but in 

clude silty sand and rubble. They form a thin veneer 

on the terrace platform. They are generally only a 

few -feet thick but toward the seaward edge of a terrace 

they may be as much as 10 to 15 feet thick. At places 

they are represented by only a single layer of pebbles 

and interstitial sand. Owing to inequalities on the 

platform, to submarine scouring, or to subaerial erosion 

prior to deposition of the nonmarine cover, marine de 

posits are at places absent. 

The present sea cliff and excavations afford the best' 

exposures of marine terrace deposits. With few excep 

tions they were not found on terraces above the first- 

-in natural exposures inland from the coast. Inasmuch 

as marine strata wese recognized at numerous localities 

in artificial exposures on terraces older than the first, 

their usual absence in natural exposures is due pre 

sumably to concealment by surficial debris and soil. 

Additional localities will be found doubtless as resi 

dential development continues. Marine terrace de 

posits that are exposed only in highway cuts and other 

excavations are not shown on the geologic map (pi. 1), 

except in San Pedro. Their .outcrop width on steep 

declivities is necessarily exaggerated on a map of the 

scale of plate 1. Owing to their thinness and uncon- 

solidation marine terrace deposits are geologically 

ephemeral unless protected from erosion. In the Palos 

Verdes Hills they are saved from destruction by the 

overlying thick nonmarine cover. 

Marine deposits have been found on 9 of the 13 

main terraces -recognized. Those on the first or lowest 

terrace are the only deposits that have received a 

formal stratigraphic designation. They constitute 

Arnold's upper San Pedro series, now known as the 

Palos Verdes sand. 

MARINE TERRACE DEPOSITS OLDER THAN PALOS 

VERDES SAND 

Aside from a preliminary generalized account, 25 

marine terrace deposits older than the Palos Verdes 

sand have not been recorded, with one exception. As 

these deposits and their fossils are of exceptional 

interest, the localities where they were found are 

described or mentioned under the following heading. 

STRATIGRAPHY AND LITHOJLOGY 

TWELFTH TERRACE 

The oldest and highest marine terrace deposits found 

are on a remnant of the twelfth terrace at an altitude 

of 1,215 feet above sea level. They are exposed in a 

cut on Crest Road, on the southeast slope of San Pedro 

Hill (locality 75), where the following section was 

measured: 

Section of deposits on twelfth terrace in cut on Crest Road on 

southeast slope of San Pedro Hill (locality 75) 

Nonmarine cover: " . Feet 

5. Reddish-brown sand and soil__________________ 1-7 

4. Cliff rubble_____._ . ..__._ ____'___. ' 4-5 

3. Cliff rubble containing many abalones (Haliotis 

cracherodii) and a few turban shells (Tegula 

gallina) 26 wedged between stones _____________ 2 

28 Woodrlng, W. P., Fossils from the marine Pleistocene terraces of the San Pedro 

'Hills, Calif.: Am Jour. Sci., 5th ser., vol. 29, pp. 292-305,1 fig., 1935. 

29 Erroneously reported as Te.gula funebralis (Woodring, W. P., op. cit., p. 297). 

Section of deposits on twelfth terrace in cut on Crest Road on 

southeast slope of San Pedro Hill (locality 75) Continued 

Marine deposits: ' Feet 

2. Coarse-grained sand and gravel composed prin 

cipally of rock-cliff and tide-pool shells and 

fragments; includes pebbles._________________ 1-2 

1. Mixture of cliff rubble, pebbles, and cobbles, many 

of which are bored. Rests on platform of cherty 

shale, the surface of which is bored at many 

places _-__----__-__--___--___--______-____ 1 }_-2 

Most of the marine deposits of the preceding section 

may be storm-swept material, for even the lowest unit 

includes cliff rubble. The marine, shells wedged 

between the stones of unit 3, assigned to the nonmarine 

cover but representing talus rubble of the same age as 

at least the upper part of the marine strata, quite 

certainly are storm-driven. 

i 

NINTH TERRACE 

At locality 76, on Palos Verdes Drive East, marine 

fossils were found in deposits near the rear of the ninth 

terrace at an altitude of 925 feet. The terrace de 

posits, evidently a mixture of marine material and cliff 

rubble, are 13 feet thick. The highway cut exposes the 

cliff, which is apparently slightly overhanging, at the 

rear of the terrace. Fossils, including large and small 

specimens of Epilucina calif arnica,; many paired, are in 

buff calcareous silty sand containing angular bored 

stones at a place 135 feet southwest of the exposed 

ancient cliff face. The terrace platform is not exposed. 

A few small shells and shell fragments are at a higher 

level in buff calcareous silty sand containing small 

angular stones 50 feet farther to the southwest, along 

the highway (locality 76a). 

EIGHTH TERRACE 

The platform of the eighth terrace (altitude 765 feet) 

is exposed in a cut on Palos Verdes Drive East in the 

Miraleste district (locality 77). Gravel 3 to 5 feet 

thick lying on the platform contains marine fossils. 

SIXTH TERRACE 

At locality 78, also in the Miraleste district, the plat 

form (altitude .560 feet) and the vertical cliff face at the 

rear of the sixth terrace are exposed. Marine fossilif- 

erous gravel }_ to 2% feet thick lies on the platform. The 

gravel is overlain by 7 to 8 inches of sand, and above the 

sand is buff calcareous silty sand 1 to \}{ feet thick 

containing numerous echinoid spines, small shells, shell 

fragments, scattered pebbles, and angular rubble. 

At locality 79, in the Malaga Cove district near 

La Venta Inn, gravel and rubble on the platform of the 

sixth terrace (altitude 550 feet) yielded marine fossils, 

including numerous specimens of Tegula gallina. 

FIFTH TERRACE 

Fossiliferous marine, deposits were found on the fifth 

terrace at two localities. At locality 81, southwest of 

Flatrock Point, the fossils are in gravel and rubble lying 

on the platform, which has an altitude of 360 feet. At 

locality 80 (altitude 370 feet), on Crest Road, fossils are 

in coarse rubble 1 to 2. feet thick containing a few bored 

cobbles and boulders. 

FOURTH TERRACE 

At localities 82 to 89 fossiliferous marine deposits 

were observed on the fourth terrace. At locality 83 

(altitude 200 feet), on Gaffey Street near Point Fermin,

fossils were found near the seaward edge of the terrace 

in sand containing angular stones and some cobbles. 

At locality 82 nearby, on Peck Street, where the section 

given below was measured, fossils are wedged between 

ooulders a,ncl rock slabs near the rear of the terrace. 

At that locality the platform has an altitude of 240 feet. 

Section of deposits on fourth terrace on west side of Peck Street 

376 feet north of Thirty-sixth Street (locality 82) Ft. in. 

Black soil_.........._.........__.._.._... 3 0 

ISfonmarine cover: Rubble consisting of flat slabs 

of blue-schist sandstone and cherty shale in mat 

rix of sand.________________________________ 5 ' 0 

Marine deposits: Gravel consisting of cobbles and 

boulders mixed with angular rock slabs. Rock- 

cliff and tide-pool shells and a little sand in in 

terstices. R.ests on platform of blue-schist sand 

stone_..______--..-___---_--.--_-------_- 1 5-14 

A highway cut near Point Vicente (locality 84) ex 

poses the platform of the fourth and third terraces and 

the intervening cliff face, as shown on plate 23. Marine 

deposits were not recognized on the third terrace, but 

on the fourth terrace marine fossils occur in sand filling 

spaces between boulders and blocks of rock, some of 

which are 3 to 4 feet long. The platform of the fourth 

terrace is at an altitude of about 250 feet. Farther 

northwest on Palos Verdes Drive West, at locality 85, 

at an altitude of 250 feet, fossiliferous gravel and 

con,rse rubble are 1 to IK feet thick. ° 

At the localities so far described the marine .deposits 

consist of clean gray sand, calcareous silty buff sand, 

gravel, and a mixture of gravel and cliff rubble, and 

the fossils are rock-cliff and tide-pool species. At 

Bluff Cove, however, where the present sea cliff has 

retreated to the fourth terrace, a large fauna including 

offshore shells in addition to rock-cliff and tide-pool 

shells was collected from reddish-brown sand and 

relatively fine-grained rubble (locality 86; altitude 260 

feet). The terrace deposits are evidently a mixture 

of marine and nonmarine constituents, the latter 

predominating. The offshore shells presumably were 

swept in over the platform, which, was probably narrow, 

by storm waves and were mixed with sand and rubble 

lying at the foot of the cliff backing the platform. 

On the north slope of the hills terrace remnants, 

thought to represent the fourth terrace, are at a higher 

altitude than the fourth terrace on the west and south 

coasts. Fossiliferous gravel and calcareous, silty sand 

are poorly exposed on Campesina Road in the Malaga 

Cove district (locality 87; altitude 375 feet). On 

Campesina Road, half a mile southeast of locality 87, 

gravel at an altitude of 475 feet contains small clusters 

of the wormlike gastropod Aletes squamigerus. At 

locality 88, on Palos Verdes Drive North, where no 

bench is discernible, a foot of fossiliferous gravel 

(altitude 510 feet).is overlain by black soil, no non- 

nmrino cover intervening. Farther southeast on Palos 

Verdes Drive North, at locality 89 (altitude 460 feet), 

Tegula gallina and Hinnites giganteus were found in 

sand and gravel containing finely broken shell, frag 

ments and stones. The deposits at that locality are 

probably close to the unexposed platform and grade 

upAyard into the noumarine cover, which includes much 

schist debris. 

THIRD TERRACE 

Marine deposits were found at altitudes of 160 to 

ISO feet on the third terrace, on the slope between the 

fourth and first terraces, west and southwest of Fort 


McArthur Lower Reservation in southern San Pedro. 

In that area the third terrace forms locally a narrow, 

steeply sloping bench, but a bench is generally not 

apparent. At locality 90 the terrace deposits, 2 to 3 

feet thick, consist principally of rubble and interstitial 

fossiliferous sand. A mineralized femur of an immature 

gopher, possibly Thomomys, and marine fossils were 

collected from rubble and sand a foot thick at locality 

91. Rubble, gravel, and sand a foot thick at locality 

92 contain marine fossils. 

On the southwest face of Hilltop quarry (locality 93), 

northwest of San Pedro, a thin veneer of gravel rests on 

an uneven platform of soft Pleistocene marl at an 

altitude of 220 feet. The gravel ranges in thickness 

from a layer-of pebbles to several layers half a foot 

thick. Worn and broken shells, representing a pro- 

tected-bay facies like that on the first terrace in this 

region, were found in a pocket of sand in the gravel. 

SECOND TERRACE 

The second terrace is the lowest terrace along almost 

the entire length of the windward side of the hills 

west and south. In extensive areas the present sea 

cliff truncates this terrace and exposes the platform 

'and overlying marine gravel and sand, which is 1 to 12 

feet thick. Here and there angular stones are mixed 

with the gravel or predominate over gravel. Fossils 

were collected along the sea cliff at localities extending 

from the Point Fermin district to Lunada Bay (locali 

ties 94, 96, 98 "to 103; altitude 100 to 140 feet). 

Locality 94, near Point Fermin, where chitons are 

exceptionally abundant, was described many years ago 

by the Chaces,27 but it is now virtually destroyed, 

owing to park development. At that locality the fos 

sils are in 2 to 5 feet of angular rubble, sand, and a 

few cobbles resting on the platform of blue-schist sand 

stone. At locality 102, on the south side of Agua 

Amarga Canyon at Lunada Bay, the fossiliferous sedi 

ments consist of calcareous silty sand containing 

minute shells and broken echinoid spines. 

Fossiliferous gravel at the top of the cliff at Flatrock 

Point lies apparently on a small remnant of the second 

terrace (locality 104; altitude 150 feet). 

A cut on Corta Road, at locality 105, in the Malaga 

Cove district, exposes the platform, of the second ter 

race at an altitude of 190 feet. At that locality a 

large fauna, consisting of rock-cliff, tide-pool, and pro- 

tected-bay shells, was found in granule-gravel that'was 

trapped by storm waves in a niche and sealed by 

boulders. 

In San Pedro the second terrace forms locally a 

distinct bench and at other places merges into the first 

terrace. Mr. E. P. Chace, of San Pedro, reports that 

gravel and sand containing a fauna like that in deposits 

on the first terrace in northern San Pedro were pene 

trated in an excavation for the high school on the 

south side of Fifteenth Street, between Leland and 

Alma, at an altitude of about 170 feet. Pockets of 

fossiliferous gravel are exposed on the north side of 

Second Street, between Gaffey and Cabrillo. A path 

in Peck Park exposes fossiliferous gravel on a terrace 

remnant that represents probably the second terrace 

but may be the third (locality 106; altitude 200 feet). 

27 Chace, E. P., and E. M., An unreported exposure of the San Pcdro Pleistocene: 

Lorquinia, vol. 2, No. 6, pp. 41-43, 1919.

56 


PALOS VERDES SAND 


Marine deposits on the youngest or first terrace, 

which is well developed on the leeward side of the hills 

in San Pedro, are designated the Palos Verdes sand. 

They were described by Delos and Ralph Arnold 28 and 

at greater length by Ralph Arnold 29 under the designa 

tion "upper San Pedro series." In a manuscript report 

on the geology of the Palos Verdes Hills Kew restricted 

the name "San Pedro" to the Arnolds' lower San Pedro 

series and proposed the name "Palos Verdes formation" 

for their upper San Pedro series. The designation 

"Palos Verdes formation" first appeared in print in 

1926. 30 Inasmuch as sand is the prevailing lithologic 

type, the term "Palos Verdes sand" is used in this re 

port. Arnold 31 recognized that his upper San Pedro 

series corresponds in areal extent to the "lower or 50- 

foot terrace." He did not, however, differentiate the 

marine deposits from the nonmarine cover. Inasmuch 

as the marine deposits and their fossils were emphasized, 

the name "Palos Verdes sand" is restricted herewith to 

the marine deposits in Arnold's upper San Pedro series, 

that is, to the marine deposits on the lowest terrace. 

In the original description of the upper San Pedro 

series exposures along the water front in the present 

northern part of San Pedro were described as represent 

ing the best development of that unit.32 Later Arnold 33 

expressly stated that the type locality is "at the north 

end of the San Pedro Bluff near the lumber yard." 

Though that locality-is shown on a geologic map in this 

report (pi. 14, locality 113), it is no longer in existence. 

The water front and adjoining region in San Pedro are 

regarded as the type region. 

The Palos Verdes sand, like the older marine terrace 

deposits, consists of a thin veneer on the terrace plat 

form, which bevels formations ranging in age from lower 

Pleistocene to Miocene. Also like the older marine 

terrace deposits, the strata consist generally of coarse 

grained sand and gravel but include silty sand and 

silt. Limestone cobbles are the prevailing constituent 

of the gravel, but granitic and schist pebbles are locally 

abundant. The Palos Verdes generally ranges in thick 

ness from a few inches to 15 feet and is usually less than 

10 feet. At places it consists of thin lenses, and at other 

places it is absent. In San Pedro the terrace and the 

deposits lying on it have the expectable gentle seaward 

slope. Along the north border of the hills they are de 

formed, mildly in the eastern part of the area, more 

strongly in the western part. In the area where they 

are deformed the deposits were originally terrace de 

posits, but the platform.on which they rest has no longer 

the usual form of a terrace. In the eastern part of the 

area where deformation has taken place the marine 

deposits are the equivalent of the undeformed deposits, 

at least so far as can be determined by ordinary strati- 

graphic methods. Farther west where the deformation 

is stronger the marine deposits are as much as 30 to 35 

feet thick and possibly may be the equivalent of more 

than one set of terrace deposits in the area where no 

deformation took place. Nevertheless the term "Palos 

Verdes sand" is used, even in the area of strong defor- 

« Arnold, Delos and'Ralph, The Marine Pliocene and Pleistocene stratigraphy of 

the coast of Caifornia: Jour. Geology, vol. 10, pp. 120, 126-128, 1902. 

s» Arnold, Ralph, op. cit. (California Acad. Sci. Mem.,-vol. 3), pp. 12, 23-30, 1903. 

80 Tieje, A. J., The Pliocene and Pleistocene history of the Baldwin Hills, Los An 

geles County, Calif.: Am. Assoc. Petroleum Geologists Bull., vol. 10, pp. 502-503,1926. 

»i Arnold, Ralph, op. cit. (California Acad. Sci. Mem., vol. 3), p. 27,1903. 

" Arnold, Delos and Ralph, op. cit., p. 126. 

" Arnold, Ralph, op. cit. (California Acad. Sci. Mem., vol. 3), p. 27,1903. 

mation, because equivalents of two or more sets of 

terrace deposits, if represented, were not differentiated. 

The Palos Verdes sand is shown on the geologic maps 

(pis. 1, 14, 21) only at localities where it was observed 

and identified by marine constituents. It is doubtless 

represented at many other places but is covered with a 

mantle of surficial debris and soil. At other places it 

may be represented by unfossiliferous sand mapped as 

part of overlying or underlying units. 

In thickness, and presumably also in time duration 

the Palos Verdes sand represents a small fraction of 

ordinary formations in the Coast Range. Assignment 

of formation rank and naming of the marine deposits 

would be justified as fully for any other terrace as for 

the marine deposits on the youngest terrace. A formal 

name is used for the marine deposits on the youngest 

terrace, because they are extensive and because they 

have played an important part in descriptions of Coast 

Range geologic history. 

STRATIGRAPHY AND UTHOUOGY 

DEADMAN ISLAND 

On Deadman Island the Palos Verdes sand con 

sisted of 2 to 5 feet of gravel and coarse-grained sand 

containing marine fossils, generally broken and worn. 

These virtually horizontal strata truncated the gently 

dipping San Pedro sand. They were locally consoli 

dated by the addition of calcareous cement. Arnold 34 

identified cobbles of -fossiliferous cemented San Pedro 

sand in the gravel. 

SOUTHERN SAN PEDRO 

The Palos Verdes sand was found at only a few 

localities along the coast south of Timms Point. In 

much of that area, however, the strata at and near the 

top of the sea cli'ff are poorly exposed or unexposed. 

The following section was measured along the north 

side of the ravine, at the north boundary of Fort 

McArthur Lower Reservation (locality 108) Arnold's 

Crawfish George's locality. 35 

Section of Palos Verdes sand at north boundary of Fort McArthur 

Lower Reservation (locality 108, Arnold's Crawfish George's 

locality) 

Ft. in. 

Black soil____-___-_________________--______'-_ 3 0 

Nonmarine terrace cover: 

3. Brownish sand, lighter in color toward base.. 4 0 

Palos Verdes sand: 

2. Grayish-brown silty, calcareous sand contain 

ing many shells and shell fragments -and 

scattered small pebbles. Gastropods abun 

dant, especially "Nassa". _______________ 11-13 

1. Grayish-brown silty, calcareous sand, includ 

ing a 2-inch to 4-inch Macoma layer at base. 

Contains few pebbles and cobbles. Gastro 

pods not abundant. Rests on platform of 

Miocene mudstone__-------------____-_- 1 1-2' 

Maximum thickness of Palos Verdes 

sand_____.________'________________ 2 3. 

Fossils from the preceding locality include Fusitriton 

oregonensis, Exiloidea rectirostris, and other northern 

species. They represent an unusual faunal facies of 

the Palos Verdes. The lithologic facies also is unusual.. 

A similar lithologic and faunal facies is represented, 

farther south, at locality 107, near Cabrillo Beach. 

s< Arnold, Ralph, op. cit. (California Acad. Sci. Mem., vol. 3), p. 23,1903. 

as Idem, p. 24.

NORTHERN SAN PEDRO 

In the northern part of San Pedro the Palos Verdes 

sand is exposed in numerous street cuts and in some 

natural exposures along the seaward edge of the terrace. 

Wherever a street is cut below the level of the first ter 

race, the terrace platform and Palos Verdes sand, if 

present, are exposed. Changes have been so numerous 

since the current edition of the Wilmington topographic 

map was issued that it is impractical to make the alter 

ations that would be necessary to show the present areol 

geology; furthermore, the areal pattern is continually 

changing. Alterations have been made at only a few 

important localities. (See pi. 14.) 

At places, even near the seaward edge of the terrace, 

the Palos Verdes sand is lenticular and is locally absent, 

as on the east side of Palos Verdes Street near Third and 

on Ancon Street between First and Santa Cruz. At 

many places west of Pacific Avenue the nonmarine cover 

rests directly on the terrace platform. New cuts 

farther west along First Street, between Grand and 

Gaffey near the landward edge of the terrace, show, 

however, pockets of fossiliferous sand and gravel. 

Those cuts are not shown on the geologic map (pi. 1); 

neither are outcrops of fossiliferous sand and gravel in 

cuts along the extension of Gaffey Street into San Pedro 

at the Elberon Street overpass. 

Coarse-grained sand and gravel ranging in thickness 

from a few inches to 8 feet are the prevailing lithologic 

types in northern San Pedro. If only part of the forma 

tion is fossiliferous, that part is generally at the base. 

On the west side of Beacon Street, northward from 

O'Farroll, however, 1 to 3 feet of fossiliferous sand and 

gravel composed of limestone cobbles overlie 3 to 8 feet 

of barren brownish-gray sand at the base of the forma 

tion, as shown in the section on page 47. The following 

section, measured on the west side of Pacific Avenue, 

between Oliver and Bonita Streets (locality 112), is 

representative of the sand-gravel facies: 

Section of Palos Verdes sand on west side of Pacific Avenue, midway 

between Oliver and Bonita Streets (locality 112) 


3. Fine-grained gray sand including stringers of 

gray silty sand 1 to 10'inches thick. Grades 

upward into overlying reddish-brown sand & '« 

of nonmarine terrace cover._____________ 5 6 

2. Fossiliferous moderately coarse-grained sand, 

coarse-grained sand, and gravel (locality 

112). Pebbles consist of limestone and 

cherty shale and have maximum length of 7 

inches; many limestone pebbles bored___ __ 12-19 


sand____---_-_-_--__-_--------_. 7 1 


1. Moderately coarse-grained gray cross-bedded 

unfossiliferous sand. Base not exposed. __ 9 6 

Large shells of the gaper clam (Schizothaf.rus imt- 

tallii), oriented in life position, siphon end upward, 

may bo seen in their burrows on the south side of 

Second Street between Pacific and Mesa and on the 

west side of Center Street between Santa Cruz and 

First. At the southeast corner of Third and Mesa 

Streets transverse sections of burrows filled with Palos 

Verdes sand and shells are visible in the San Pedro 

sand 6 to 8 feet below the base of the Palos Vexdes. 

On the west side of Beacon Street, 150 feet south of 

Dreifus, a channel-filling lens of gravel at the base of 

the Palos Verdes is 50 feet wide at the top, 15 feet wide 

at the base, and 6 feet thick at the middle. 


A beach facies, consisting of cross-bedded sand 

containing worn and relatively small shells and shell 

fragments, was formerly represented near the north 

west corner of Palos Verdes and Eighth Streets (lo 

cality 109), where the section given below was measured. 

The strata at that locality have been removed recently, 

and new outcrops nearby to the west represent the 

usual sand-gravel facies. 

Section of Palos Verdes sand in lot at northwest corner of Palos 

Verdes and Eighth Streets (locality 1Q9) 


4. Reddish-brown sand. 


3. Shell fragments in matrix of cross-bedded fine 

grained sand__-____---___.-____________ 1 11-19 

Cross-bedded fine-grained gray sand including 

two, or locally three, 1-inch to 2-inch layers 

of small worn gastropods (locality 109). 

Thickness variable.____________________ 1 1 

San Pedro (?) sand: 

1. Gray sand. 


In northeastern San Pedro, silty sand containing 

a Macoma layer or layers overlies the usual fossiliferous 

coarse-grained sand and gravel. The silty sand indi 

cates evidently more protected water than does the 

underlying sand and gravel. MocoTna-bearing silty sand 

was represented at Arnold's lumber yard locality (locality 

113), 36 now destroyed. At that locality a basal fossili 

ferous gravel that varied in thickness but was as much as 

6 feet rested on an uneven surface of cross-bedded San 

Pedro sand having a relief of 1 to 2 feet. Silty sand 

overlying the gravel included a Macoma layer a foot 

above the top of the gravel. The following section, 

measured on the west side of this remnant of the lowest 

terrace, now destroyed, shows four Macoma layers in 

a thickness of about 5 feet: 

Section of Palos Verdes sand on east side of Harbor Boulevard 

opposite Dreifus Street 

Ft. in. 


6. Reddish-brown sand. Thickness estimated.... 20 0 


5. Brownish-gray silty sand including a 3-inch 

Macoma layer at base...._________________ 1 7 

4. Brownish-gray silty sand including a 4-inch to 

5-inch Macoma layer at base___..___.____ 1 0 

3. Brownish-gray silty sand including a 4-inch to 

6-inch Macoma-"Paphia" layer at base._._ 1 5-8 

2. Brownish-gray silty sanfl containing scattered 

shells, mostly Macoma. ____________ _______ 2-6 

1. Fossiliferous gravel.____'____________________ 2 2-7 

Maximum thickmess of Palos Verdes sand.._ 7 4 

The following section measured nearby, on the west 

side of Harbor Boulevard at locality 114, also shows 

a Macoma layer in silty sand. 

Section of Palps Verdes sand on west side of Harbor Boulevard near 

crossing of Pacific Electric tracks (locality 114) 

Ft. in. 


4. Brownish-sand grading upward into reddish- 

brown sand____________________________ 12 0 

" Arnold, Ralph, op. cit., p. 27. 

Ft. 

6 

In.


Section of Polos Verdes sand on west side of Harbor Boulevard' 

near crossing of Pacific Electric tracks (locality 114)~Con. 


3. Silty sand and silt containing scattered pelecypods--__-___--_----____--________________ 

2 8 

2. Coarse-grained gray sand containing scattered 

shells, mostly broken, and shell fragments, 

grading upward into silty sand of finer grain 

including a 9-inch to 12-inch Macoma layer, 

the top of which is 11 inches below top of unit 

(locality 114)__________--________________ 3 5 

1. Brownish silty sand grading laterally into clean 

gray sand. Base not exposed____________ 1 7 + 

Exposed thickness of Palos Verdes sand.._ 7 8 

Fossils were collected in the northern part of San 

Pedro at localities 109 to 114. At localities where they 

are found in gravel or cross-bedded sand, fragments are 

more abundant than unbroken shells,, but in large ^col 

lections many specimens are unbroken, and many pele- 

cypods are paired. Pockets have concentrates .of 

coarse-grained sand arid small or young shells. The 

proportion of unbroken shells in silty sand is larger than 

in gravel and cross-bedded sand. Southern species, 

including Crassinella brannefi and Trachycardium pro- 

cerum, were not found south of localities 112 and 113. 

GAFFEY ANTICIINE AND SYNCLINE EAST OF PAIOS VERDES DRIVE NORTH 

Northwest and north of San Pedro the first terrace 

and its deposits dip gently northeastward toward the 

trough of the Gaffey syncline and are gently arched 

over the Gaffey anticline. The terrace platform and 

overlying terrace deposits, including here and there the 

Palos Verdes sand, may be traced, except for gaps due 

to stream erosion, into the area where they are mildly 

deformed. In perfect exposures the Palos Verdes sand 

is seen to be at some places lenticular and locally absent, 

but its apparent absence in extensive areas is probably 

due to lack of exposures. In the eastern part of the 

Gaffey anticline and syncline, as farther south, fossili- 

ferous coarse-grained sand and gravel are the prevail 

ing types in the Palos Verdes. They are a few inches 

to 11 feet thick, generally about 5 feet. 

At locality 117, along a cattle trail outside the fence 

at the south boundary of the Standard Oil Co. tank 

farm, fossiliferous gravel is made up of limestone pebbles 

and cobbles, which are not as riddled with holes of bor 

ing maruie annuals as limestone cobbles in the Lomita 

marl forming part of the terrace platform. The gravel 

is identified as the Palos Verdes but may correspond to 

marine deposits on the second terrace farther southeast. 

On Harbor Boulevard, opposite the San Pedro Lum 

ber Co. (locality 120), strata assigned to the Palos Verdes 

sand are 11 feet .thick. (See section, p. 48.) The base 

of the Palos Verdes is drawn at the base of the fossili- 

ferous gravel and sand that contains southern species 

and that rests on an imeven surface of sand assigned to 

the San- Pedro. As explained under the description of 

the San Pedro, however, the sand assigned to that form 

ation may represent also the Palos Verdes. 

' A formerly accessible locality for the Palos Verdes is 

on the north side of Anaheim Boulevard, on the bluff 

overlooking the east edge of Bixby Slough (locality 124). 

At that locality a lenticular cross-bedded abundantly 

fossiliferous layer in brownish sand has a maximum 

thickness of-4% feet and rests on San Pedro silt and silty 

sand forming the terrace platform. 

On the west side of Gaffey Street, 350 feet south of 

Anaheim Boulevard, an isolated transverse section of 

fossiliferous Palos Verdes sand, 16 inches long and 

7 inches high, is sharply limited by cross-bedded San 

Pedro sand at a level 3 feet below the terrace platform 

(locality 129). The -Palos Verdes sand is absent on 

the platform. Another transverse section nearby, 5 

feet below the platform, is at least 6 feet long and 2 feet 

high. The material in these sections fills openings 

that are apparently too large for burrows of marine 

animals. They represent holes of unknown origin 

filled with debris from the cleanly swept platform. 

A section measured farther south on the west side 

of Gaffey Street at locality 127, where granite pebbles 

are exceptionally abundant in the Palos Verdes, is as 

follows: 

Section of Pleistocene strata, including Palos Verdes sand, in 

abandoned sand pit on west side of Gaffey Street (locality 127) 


5. Coarse-grained gray sand grading upward 

into reddish-brown sand (nonmarine terrace 

cover) and soil_--__----__-_____________ 8 - 0 

4. Fossiliferous gravel and coarse-grained gray 

sand (locality 127). Limestone pebbles 

relatively scarce; granitic pebbles abun- 

dant. Contact at base irregular,_________ 2 2 

Thickness of Palos Verdes sand-_______ 10 2 


3. Massive gray limonite-stained sand_________ 4 8 

2. Gravel, .consisting of granitic pebbles and 

coarse-grained gray sand. Contact at base 

irregular._____________________________ 1 8 

1. Coarse-grained cross-bedded gray sand. Base 

not exposed.______________________!___ 10+ 

Along the greater part of the slope on the east side 

of Gaffey Street identification of the Palos Verdes is 

uncertain, as fossiliferous layers were not found in the 

formation except at localities 122 and 123. Strata 

thought to represent the Palos Verdes between these 

localities include gray silt and olive-gray silty sand. 

Aeguipecten-Anomia and Chione-Ostreal&yers in under 

lying sand and gravel are assigned to the San Pedro 

sand. 

At localities 125, 131, and 132, on the south limb of 

the Gaffey anticline west of Gaffey Street, the Palos 

Verdes is represented by an Anomia-Ostrea facies. The 

strata consist of brownish-gray cross-bedded sand, % to 

2 feet thick, resting on Miocene mudstone or on cross- 

bedded gray sand referred to the San Pedro. No 

characteristic Palos Verdes fossils were found at locali 

ties 125 and 132, but the collection from locality 131 

includes a worn fragment of the southern Trachycardium 

procerum. On the south flank of the Gaffey syncline, 

at locality 58 on Western Avenue, an Anomia-Ostrea 

facies is included in strata identified as the. San Pedro 

sand. At that locality the base of the Palos Verdes 

is drawn at the base of overlying fossiliferous gravel, 3 

feet thick, consisting principally of schist pebbles. 

Fossils from the schist gravel include a small specimen 

of Trachycardium procerum. The Anomia-Ostrea facies 

on opposite flanks of the Gaffey syncline may be of the 

same age. It appears 'probable, however, that a 

similar .facies was developed under similar environ 

mental conditions in an arm of the sea behind the 

actively growing Gaffey anticline during both Sari Pedro 

time and Palos Verdes time. 

A cut on Palos Verdes Drive East, at locality 133, 

on the east side of George F Canyon, exposes gravel 

composed of limestone cobbles and sand resting on the 

platform at the rear of a terrace (pi. .24, A). A few 

fossils were found in gravel and sand 100 feet farther 

north where the platform is not exposed. The platform


I. I.HMIl \ \IARL IN* TYPE REGION VI I.UMIIA ul \HII1. 

Note minor faults H!IOWII by displacement of dark-colored layer of glauconitic sand. The dark-colored strata at top of quarry face consist of sand and gravel assigned to 

San Pedro (?) sand. 

B. LOMITA MARL RESTING UNCONFORMABLY ON MALAGA MUDSTONE MEMBER OF MONTKH ! : > -II Ml, VS EXPOSED IN HIGHWAY CUT ON 

SOUTH LIMB OF GAFFEY ANTICLINE. 

Note minor thrust fault along contact, shown by displacement of base of terrace cover, a, Nonmarine cover of lowest terrace; b, San Pedro sand; c, Lomita marl; d, Malaga 

mudstone member of Monterey shale. 

LOMITA MARL.


A. SAN 1'EDRO SAND (a) LYING UNCONFOHMABLY ON MALAGA MUDSTONK MEMBER OF MOVI'EKKY SHALE (h) AT LOADING HOPPER OF 

SIDEBOTHAM NO. 2 SAND PIT. 

Photograph by U. S. Grant. 

B. CROSS-BEDDED SAN PEDHO SAND (b) OVERLAIN UNCONFORMABLY BY PALOS VKUDES SAND AND NONMAKI.NE TERRACE COVER (a) IN 

SIDEBOTHAM NO. 2 SAND PIT. 

Photograph by U. S. Grant. 

PLEISTOCENE FORMATIONS ON NORTH BORDER OF PALOS VERDES HILLS.


SAN PEDRO SAND IN SIDEBOTHAM NO. 1 SAND PIT. 

The pit is about 100 feet deep. The little hill has a cap of nonmarine terrace cover.


.-I. SAN 1'LDUO SAiNU LN KICIIAKU HALL SAM) I'll'. 

fi. SAND PIT ON WEST SIDE OF FOURTH RAVINE WEST OF HAWTHORNE AVENUE. 

Lomita marl (c), San Pedro sand (b), and unconformably overlying Palos Verdes (?) sand and nonmarine terrace cover (a). 

PLEISTOCENE FORMATIONS ON NORTH BORDER OF PALOS VERDES HILLS.

is at an 1 altitude of 365 feet, much higher than the rear 

of the first terrace in San Pedro. It may represent the 

second or third terrace, but is identified provisionally 

as the first. The marine deposits are, therefore, iden 

tified provisionally as the Palos Verdes. 

Fossils wore collected in the eastern part of the Gaffey 

anticline and syncline at localities 115 to 133. These 

collections include southern species, notably Crassinella 

branneri, Dosinia ponderosa, Chione gnidia, and Trachy- 

cardium procerum, except those from localities 125, 132, 

and 133. 'Dosinia, ponderosa was not found south of 

localities 118 and 119, and Chione gnidia was found only 

at locality 123. 

GAFFEY ANTICLINE WEST OF PALOS VERDES DRIVE NORTH 

The Palos Verdes sand was identified at localities on 

the north flank of the Gafl'ey anticline west of Palos 

Verdes Drive North but was not recognized in the 

adjoining fyncline. 

On the west side of Palos Verdes Drive North, 300 feet 

south of Anahoim Boulevard (locality 134), where the 

base of the formation is not exposed, lenses of fossil 

iferous coarse-grained sand, 8 inches to l^feet thick, are 

separated- by a foot of silty sand. Float Anomia, 

Ostrea, and broken sand dollars occur on the slope of 

overlying silty sand, also considered of Palos Verdes age. 

One of the best localities for Palos Verdes fossils is in a 

ravine west of Palos Verdes Drive North, near the head 

of Senator Street in Harbor City (locality 135). Fossils 

are scattered through 5% to 6 feet of brownish-gray 

coarse-grained sand resting on an uneven surface of 

limonite-stained gray San Pedro sand. Farther up the 

ravine lenses of fossiliferous sand are overlain by 8 to 

15 feet of barren olive-gray silt and sandy silt. 

In addition to the localities mentioned, fossils were 

collected from sand and gravel at localities 136 to 138. 

Characteristic southern species, including Crassinella 

branneri, Dosinia ponderosa, Chione gnidia, and Tra- 

chycardium procerum, were not found in the western 

part of the Gaffey anticline west of locality 135. 

NORTH BORDER OF HILLS BETWEEN BENT SPRING CANYON AND 

, ' HAWTHORNE AVENUE 

The Palos Verdes sand is not recognized on the north 

border of the hills between Bent Spring Canyon and 

Agua Magna Canyon. In that area strata identified as 

the nonmarine terrace cover Test on sand and gravel 

assigned to the San Pedro sand. In the absence of 

fossils it is difficult, however, to differentiate the Palos 

Verdes from the San Pedro and the nonmarine cover. 

On the west side of Agua Magna Canyon float Anomia 

fragments were observed on the surface of a gravel com 

posed of limestone cobbles that represents probably the 

Palos Verdes. In the first sand pit (Graham Bros.) 

west of Agua Magna Canyon 15 feet of coarse-grained 

sand and limestone cobbles are assigned to the Palos 

Verdes^ The strata dip 15° to 20° northeastward at 

approximately the same rate as the underlying San 

Pedro sand. On the east face of the pit fossils were 

found at the top of a basal gravel 3. to 7 feet thick 

(locality 139) and also 5 feet higher at the top of a 

gravel 1 foot thick (locality 139a). In the adjoining 

sand pit to the west sand that includes lenses of lime 

stone cobble gravel may represent the Palos Verdes, 

but no fossils were observed. Pockets of fossiliferous 

sand and gravel are exposed in a cut at the workings of 

the Dicalite Co. (locality 140). 

592787 45 6 


Strata assignable to the Palos Verdes were not identi 

fied in the Richard Ball sand pit between Agua Negra 

Canyon and Hawthorne Avenue. Coarse-grained sand 

and limestone cobble gravel exposed on Hawthorne 

Avenue and the adjoining ravine are assigned to the 

Palos Verdes. Fossils collected from sand at locality 

141 include numerous specimens of Donax gouldii. 

The small collections of fossils from the area between 

Bent Spring Canyon and Hawthorne Avenue do not 

include characteristic Palos Verdes species. 

NORTH BORDER OF HILLS BETWEEN HAWTHORNE AVENUE AND MALAGA 

COVE 

Along the north border of the hills, between Haw 

thorne Avenue and Malaga Cove, deformed strata 

mapped as the Palos Verdes sand are as much as 30 to 35 

feet thick twice as thick as the maximum thiclaiess 

farther southeast. The upper part of this thick section 

is considered the equivalent of the Palos Verdes, and 

perhaps the entire section is. For the geology of the 

area immediately northwest of Hawthorne Avenue see 

plate 21. 

In the fourth ravine west of Hawthorne Avenue gravel 

composed of limestone cobbles and sand un conformably 

overlap the San Pedro sand (pi. 20, J3). Though no 

fossils were found in these strata, they represent prob- 

ablyj the Palos Verdes, in view of relations in the fifth 

ravine. As shown in figure 13, the fifth ravine west of 

Hawthorne Avenue exposes 30 to 35 feet of sand and 

gravel dipping 22° to 26° northeastward and resting 

with marked unconformity on the San Pedro sand and 

the underlying Lomita marl. The basal gravel, ap 

parently barren of fossils, consists of relatively small 

granitic and limestone pebbles. The upper gravel is 

made up of limestone pebbles, cobbles, and boulders, 

some as much as 2 feet long. The intervening sand, 

gray in the lower part and brownish-gray in the upper 

part, includes stringers of gravel composed of pebbles of 

cherty shale and limestone. The upper gravel at local 

ity 142 is sparingly fossiliferous. It contains Trachy- 

cardium procerum, this locality being the only one west 

of locality 135 where this southern species was found, 

Nucella biserialis, and other species. Perhaps only the 

upper gravel represents the Palos Verdes) the under 

lying strata corresponding to marine deposits of the 

second or third terrace, or both. 

In ravines farther west along the north border of the 

hills the Palos Verdes sand was not identified. Some of 

the gray limonite-stained sand assigned to the non- 

marine terrace cover may, however, be unfossiliferous 

Palos Verdes. In the upper part of the ninth and last 

ravine west of Hawthorne Avenue the platform of 

Miocene mudstone is bored at many places. Below the 

falls a pocket of gravel composed of limestone cobbles 

possibly represents the Palos Verdes. 

MALAGA COVE 

At the north end of Malaga Cove, as at many other 

places along the north border of the hills, the Palos 

Verdes sand is apparently absent, the nonmarine terrace 

cover resting on sand doubtfully assigned to the San 

Pedro (see fig. 7). Farther south the nonmarine cover 

overlaps Pliocene and Miocene formations and is arched 

over those strongly deformed formations. South of the 

mouth of Malaga Canyon deposits on the first terrace 

are as much as 25 to 30 feet thick. The lower few feet 

include bored cobbles and are probably marine, but no 

fossils were found.

60 


FOSSILS 

FORAJVTINIFERA 

Foraminifera are abundant in the Lomita marl, parti 

cularly in foraminiferal calcareous sand and glauconitic 

foraminiferal sand, and in parts of the Timms Point 

silt. They are rare and generally are absent in the 

San Pedro sand and in the Palos Verdes sand and have 

not been found in terrace, deposits older than the Palos 

Verdes sand. Locality 64, where a Lomita-like fauna 

occurs in silty sand at the base of the San Pedro sand, 

is an exception, for at that locality Foraminifera are 

abundant. Bagg 37 described 105 species and varieties 

from the Timms Point silt at Timms Point. Galloway 

and Wissler 38 described 79 species and varieties from 

the Lomita marl at Lomita quarry. Their upper bed 39 

is unit 6 of the section on page 51; their middle and 

lower beds have not been identified. 

The numerous collections obtained during the field 

work for this report have not been identified. The 

collections represent evidently several different faunal 

associations. 

CORALS 

Small solitary corals representing presumably the 

genus Caryophyllia, three species of which were de 

scribed in Arnold's memoir, 40 occur in the Lomita marl 

and are recorded by Arnold from the Timms Point 

silt. They are relatively common in the algal bed at 

Hilltop quarry (localities 53, 53a) and in the calcareous 

sand and gravel nearby (locality 54g), thought to be 

vthe equivalent of the algal bed. 

ECHINOIDS 

Echinoids are rare in the collections at hand. Poorly 

preserved specimens of a large Dendraster were found 

in the San Pedro sand at locality 50. The collection 

from the fourth terrace at locality 84 includes fragments 

of a small Strongylocentrotus, that from the second ter 

race at locality 105 includes Dendraster fragments. 

Echinoid spines are abundant in some layers of the 

Lomita marl, and collections from some of these 

layers include also minute fragments of plates. 

Arnold 41 recorded Dendraster excentricus from the San 

Pedro sand and Palos Verdes sand, and spines from 

the San Pedro sand were assigned to Strongylocentrotus 

-franciscanus and S. purpuratus. 

BRYOZOA 

Bryozoa are very abundant in the Lomita marl and 

in the lower part of the Timms Point silt at Timms 

Point but are rare in the other Pleistocene units. 

Idmonea californica is the most abundant species. 

Encrusting Bryozoa occur at numerous localities, 

being most abundant in the algal bed at Hilltop quarry. 

Canu and Bassler 42 described 19 species from Deadman 

Island, presumably from the Timms Point silt. 

BRACHIOPODS 

Unidentified forms of Terebratalia occur in the 

Lomita marl. Terebratalia smithi was based on mate 

rial from the Timms Point silt, and Terebratalia cf. T. 

37 Bagg, R. M., Jr., Pliocene and Pleistocene Foraminifera from southern Califor 

nia: U. S. Geol. Survey Bull. 513, 1912. 

38 Galloway, J. J., and Wissler, S. G., Pleistocene Foraminifera from the Lomita 

quarry, Palos Verdes Hills, Calif.: Jour. Paleontology, vol. 1, pp. 35-87, pis. 7-12,1927. 

39 Idem, p. 36. 

< Arnold, Ralph, op. cit. (California Acad. Sci. Mem., vol. 3), pp. 86-88, 1903. 

4 > Arnold, Ralph, op. cit., pp. 90-91. 

4 > Canu, Ferdinand, and Bassler, R. S., North American later Tertiary and 

Quaternary Bryozoa: U. S. Nat. Mus. Bull. 125, p. 14, 1923. 

hemphilli and Lagueus jeffreysi also are recorded from 

that unit. 43 

MOLLUSKS 

Pleistocene mollusks from the San Pedro district 

have been described or recorded in numerous publica 

tions, beginning with Conrad's 1855 account 44 of 

material collected by Blake during the transcontinental 

railroad surveys. Since the publication in 1903 of 

Arnold's monumental memoir 45 the San Pedro dis 

trict has become a classic area for California Pleistocene 

mollusks. Arnold described 395 species and varieties 

of mollusks collected from strata now assigned to the 

Timms Point silt, the San Pedro sand, and the Palos 

Verdes sand at localities on Deadman Island, which 

has been destroyed, and along the San Pedro water 

front. The most important publications since then 

are those on deposits lying on the second terrace near 

Point Fermin, by the Chaces; 46 on the chitons, by 

Berry; 47 on the San Pedro sand at a locality now 

destroyed, near Third and Beacon Streets, by Oldroyd;48 

on the Timms Point silt, San Pedro sand, and Palos 

Verdes sand at Deadman Island, by Crickmay; 49 and 

on the Timms Point silt at Timms Point, by Clark; 50 

and by Willett. 51 Records up to the early part of 1931 

are summarized by Grant and Gale 52 in their indis 

pensable catalog, and some of the species are illustrated. 

Mollusks are generally the most abundant fossils in 

the marine Pleistocene strata and are represented in all 

but 4 of the 152 collections of Pleistocene fossils ob 

tained during the field work on which this report is 

based. Almost 100 collections were selected to repre 

sent age, facies,'andogeographic differentiation. About 

half the gastropods," almost 150 species, were identified 

in those collections. The plan to complete the identifi 

cations was abandoned when it became apparent that 

an attempt to do so would delay unduly completion of 

the report. Attention therefore was devoted to the 

stratigraphically and ecologically important forms. It 

is estimated that about 450 species and varieties of mol 

lusks are represented in the collections and that addi 

tional forms not in the collections but recorded from the 

San Pedro district would bring the total to about 500. 

Of the species and varieties identified, about 50 were 

unrecorded heretofore as fossils from the San Pedro 

district. The collections at hand do not add much to 

the recorded fauna of the Timms Point silt, San Pedro 

sand, and Palos Verdes sand, aside from a few notable 

exceptions. With few exceptions fossils from terrace 

deposits older than the Palos Verdes sand represent an 

association like that recorded by the Chaces 53 from the 

second terrace. The molluscan fauna of the Lomita 

marl, not represented along the water front but repre- 

43 Arnold, Ralph, op. cit., pp. 93-94. Clark, Alex, The coolwater Timms Point 

Pleistocene horizon at San Pedro, Calif.: San Diego Soc. Nat. History Trans.,"vol. 7, 

No. 4, table op. p. 30, 1931. 

. 44 Conrad, T. A., Report on the fossil shells collected in California by W. P. Blake, 

geologist of the expedition under the command of Lt. R. S. Williamson, United 

States Topographical Engineers: U. S. Pacific R. R. Expl., 33d Cong. 1st sess., 

H. Ex. Doc. 129, app., pp. 11-18,1855. (Reprinted in U. S. Geol. Survey Prof. Paper 

59, pp. 165-169, 1909.) 

45 Arnold, Ralph, The paleontology and stratigraphy of the marine Pliocene and 

Pleistocene of San Pedro, Calif.: California Acad. Sci. Mem., vol. 3, 420 pp., 37 pis., 

1903. 

4« Chace, E. P. and E. M., An unreported exposure of the San Pedro Pleistocene 

Lorquinia, vol. 2, No. 6, pp. 41-43, 1919. 

« Berry, S. S., Fossil chitons of western North America: California Acad. Sci. 

Proc., 4th ser., vol. 11, pp. 399-526, 16 pis., 11 figs., 1922. 

« Oldroyd, T. S., The fossils of the lower San Pedro fauna of the Nob Hill cut, San 

Pedro, Calif.: U. S. Nat. Mus. Proc., vol. 65, art. 22, 39 pp., 2 pis., 1924. 

4 » Crickmay, C. H., The anomalous stratigraphy of Deadman's Island, Calif.: 

Jour. Geology, vol. 37, pp. 617-638, 1929. 

«o Clark, Alex, The cool-water Timms Point Pleistocene horizon at San Pedro 

Calif.: San Diego Soc. Nat. History Trans., vol. 7, No. 4, pp. 25-42, 2 figs., 1931. 

« Willett, George, Additions to knowledge of the fossil invertebrate fauna of Cali 

fornia: Southern California Acad. Sci. Bull., vol. 36, pp. 61-64, pis. 24-25, 1937. 

' Grant, U. S., IV, and Gale, H. R., Catalogue of the marine Pliocene and Pleisto 

cene Mollusca of California: San Diego Soc. Nat. History Mem., vol. 1, 1931. 

M Chace, E. P. and E. M., op. cit.

son tod by 43 collections in the material at hand, is un 

recorded. It is hoped that at a future date this defi 

ciency may bo remedied and that the facies and geo 

graphic differentiation of the fauna of the Lomita marl 

and of the other Pleistocene units .may be studied 

adequately. 

The following discussion consists of comments on the 

stratigrophically and ecologically important species, 

80 of which are illustrated on plates 29-37. Inasmuch 

as; with few exceptions, the different faunas consist of 

living species grouped in different associations, most of 

the stratigrapliically important species are also evi 

dently ecologically important. Unless otherwise speci 

fied the species mentioned are still living. Dimensions 

of the figured specimens, including the types of new 

forms, and National Museum catalog numbers may be 

found on the explanation of the plates. References 

that may be found in Grant and Gale's well-indexed 

catalog M are omitted. References for recent species 

not* included in that catalog are also generally omitted, 

as they may be found in Dall's well-known publication. 55 

The following new names are proposed for Pleistocene 

mollusks: 

Gastropods: 

Elassum Woodring, n. gen., Cerithiidae. Type Bittium 

(Elachista) californicum JDall and Bartsch (p. 68). 

"Nassa" fossata coiloteva Woodring, n. var. (p. 73). 

"Nassa" deJosi Woodring, n. sp. (p. 74). 

Trifconalia coryphaena Woodring, n. sp. (p. 76). 

Pelecypods: Chlamys anapleus Woodring, n. sp. (p. 81). 

CHITONS 

The chitons, 21 species and varieties of which are 

recorded by Berry 50 from the Pleistocene strata of the 

San. Pedro district, have not been identified. Repre 

sented in collections at hand from all the units except 

the Timms Point silt, they are abundant only in terrace 

deposits. Mr. and Mrs. Chace 57 found them to be 

extraordinarily abundant in deposits on the second 

terrace near Point Fermin (locality 94), where they 

collected 350 specimens representing 15 species and 

varieties. 

GASTROPODS 

Six of the 13 species of limpets of the genus Acmaea 

represented in the collections examined were not re 

corded by Arnold, but all except the last have been 

recorded at later dates A. limatula (Lomita marl (?), 

San Pedro sand, terrace deposits, 58 and Palos Verdes 

sand (?)), A. persona (terrace deposits), A. Juniculata 

(pi. 34, figs. 1, 2; the three lower Pleistocene units), A. 

asmi (terrace deposits and Palos Verdes sand), A. 

lepisma 50 (Lomita marl), and A. cf. A. ochracea (Lomita 

marl). Limpets are most abundant in the terrace de 

posits, A. scrabra and A. limatula being the most com 

mon species. A. insessa is the only species found in all 

the Pleistocene units. 

4 Clrnnt, U. S., IV, and Gale, H. R., op. cit. 

" Dall, W. H., Summary of the marine shell-bearing mollusks of the northwest 

const of America: U. S. Nat. Mus. Dull. 112,1921. 

M Berry, S. S., OP- cit. 

» Ghaco, K. P. and E. M., op. cit.,.pp. 42-43. Berry, S. S., op. cit., p. 409. 

«> For brevity marine terrace deposits older thau the Palos Verdes sand, the only 

marine terrace deposits named, are designated simply terrace deposits. For the pur 

pose of this account they are treated as a unit, though, of course the deposits on each 

terrace are as distinct chronologically as the Palos Verdes sand. 

' Berry, S.S., New Mollusca from the Pleistocene of San Pedro, Calif., I: Bull. Am. 

Paleontology, vol. 25, No. 94a, p. 9, pi. i, figs. 3, 4,1940. 


HAL1OTIDAE 

Abalones, which are rare as fossils, were collected at 

13 localities in terrace deposits. The identifiable 

material represents Haliotis cracherodii, and fragmen 

tary remains are probably that species. Complete 

specimens were found' at localities 75 and 84. H. 

rufescens and H. julgens, as well as H. cracherodii, are 

recorded as Pleistocene fossils from the San. Pedro dis 

trict. 

FISSXJRELWDAE 

, Fissurella volcano- is one of the most abundant gas 

tropods in the terrace deposits. Virtually all the shells 

retain fresh coloration, a feature noticed by Arnold, in 

dicating a thick outer calcite layer. 

The Pleistocene species of Puncturella on the Pacific 

coast represent two groups. 60 One group, Puncturella 

proper, has a prop on the sides of the internal septum 

and includes only the northern P. galeata. That 

species is not in the collections at hand but is recorded 

from the Timms Point silt and San Pedro sand. The 

other group, which lacks the props and is apparently 

unnamed, includes P. cucullata, P. cooperi, and P. delosi. 

P. cucullata is in collections from the Lomita marl and 

Timms Point silt and is recorded from the San Pedro 

sand and Palos Verdes sand. P. cooperi (pi. 29, fig. 1) is 

abundant in the three lower Pleistocene units but was 

not recorded from the San Pedro district until recently. 61 

P. delosi (pi. 29, fig. 2), the most distinctive of the'three 

species, occurs in the Lomita marl and San Pedro sand 

and is recorded from the Timms Point silt. 62 It was 

based on Pleistocene material from Santa Barbara and 

was formerly thought to be extinct. As Willett 63 sus 

pected, the unfigured Recent P. caryophylla 64 is closely 

related to P. delosi, and represents probably that species. 

The Recent material in the National Museum consists 

of three lots dredged off Point Loma, California, by the 

Albatross at depths of 67 to 81 fathoms. The concen 

tric threads between the ribs are stronger ori fossils than 

on most Recent specimens, owing probably to slight 

abrasion. 

TROCHIDAE 

Plalistylus pupoideus, heretofore recorded only from 

the San Pedro sand, was found in the Lomita marl at 

Hilltop quarry (locality 53) and in deposits on the 

second terrace at Malaga Cove (locality 105). The 

specimens from the Lomita marl are exceptionally large. 

Tegula Junebralis, which at the present time is rare as 

far south as San Pedro, occurs in the San Pedro' sand, 

the Palos Verdes sand, and in terrace deposits up to. the 

fifth terrace, inclusive. It is differentiated -from T. 

gallina principally by the presence of puckered sutural 

lamellae and by the absence of diagonally reticulate 

sculpture and color banding. As identified it is found 

in association with T. gattina in terrace deposits at 

localities 83 and 104. T. gallina is abundant at the 

present time along the coast of the Palos Verdes Hills. 

It is likewise abundant in terrace' deposits, especially 

at localities 75, 79, 84, and 88, is found in the Palos 

Verdes sand, and is represented-by doubtfully identified 

fragments from the Lomita marl (localities 53, 53 a, 61). 

T. brunnea (Timms Point silt (?), terrace deposits, 

Palos Verdes sand), T. montereyi (Lomita marl, re- 

60 Dall, W. H., Notes on West American Emarginulinao: Nautilus, vol. 28, pp.. 

62-64, 1914. ' 

«' Willett, George, op. cit., p. 64,1937. 

«' Idem. 

M Idem. 

' «< Dall, W. H., op. cit., p.-63:


corded from Timms Point silt, San Pedro sand, terrace 

deposits, PalosVerdessand), and probably T. marcida 65 

("pulligo") 66 (Palos Verdes sand) appear to be extinct 

locally, as they are not known to be living along the 

mainland in the latitude of San Pedro. T. ligulata 

(San Pedro sand, terrace deposits, Palos Verdes sand) is 

more abundant than T. aureotincta (terrace deposits, 

Palos Verd.es sand). 

In addition to the five species of Calliostoma described 

by Arnold, C. supragranosum (recorded from deposits 

on the second terrace) was found in terrace deposits and 

may be represented by a worn and broken specimen 

from the Lomita marl at locality 37, and C. enimium 

(pi. 35, fig. 7) occurs in the Palos Verdes sand at locality 

121. C. eximium is a southern species said to range 

from Gatalina Island to Mazatlan, Mexico, and has not 

been reported heretofore as a fossil from California. C. 

decarinatum 67 (" canaliculatum") is the most abundant 

Calliostoma, being represented in all the Pleistocene 

units. The only specimen from terrace deposits is, 

however, a worn and broken shell. C. ligatum ("cos- 

tatum ") is likewise found in all the units. C. virgineum 68 

(Lomita marl (?), San Pedro sand, Palos Verdes sand) 

appears to be the name for the species generally known 

as C. "annulatum." The recently described C. gran- 

tianum, 69 based on material from the Lomita marl at 

Hilltop quarry, is not recognized in the collections 

at hand. 

Cidarina cidaris is represented by imperfect speci 

mens in the Timms Point silt .and by a doubtfully identi 

fied fragment in the Lomita marl at locality 41. 

Turcica caffea (pi. 32, figs. 1, 2) was found only in the 

Timms Point silt but is recorded from the San Pedro 

sand at Deadman Island. The type locality of this 

species is presumably Monterey, where, as recorded by 

Gabb, it was dredged at a depth of 20 fathoms. 'Gabb 

also mentioned, however, fossils from San Pedro and 

Santa Barbara. No specimens from Monterey are in 

the National Museum. On the fossils from the Timms 

Point silt the sculpture and peripheral spiral are of 

variable strength on the later whorls. None of the few 

available Recent shells from the California coast 

(La Jolla, San Diego) are as large as the fossil shown on 

plate 32, figure 1, and none are as weakly sculptured as 

the fossil shown on plate 32, figure 2. T. caffea brevis, 70 

from the Acila .and Pecten zones of the San Joaquin 

formation (upper Pliocene) of the Kettleman Hills, is 

more strongly sculptured than the Timms Point fossils 

and Recent California shells, and has a stronger peri 

pheral spiral. In general sculpture it resembles more 

closely a large specimen (length 30 millimeters), larger 

than any California fossil or .Recent shell available, 

dredged off Cape San Lucas, Lower California, at a 

depth of 66 fathoms. T. caffea brevis has more tightly 

coiled later whorls than the Lower California form. 

The strong peripheral spiral suggests that brevis is 

more closely related to the Recent Japanese T. im- 

perialis than to T. caffea. The comparison between 

' Gould, A. A., Descriptions of shells from the Gulf of California and the Pacific 

coasts of Mexico and'California: Boston Jour. Nat. History, vol. 6, p. 381, pi. 14, 

flg. 11,1853 ("Trochus," Monterey). 

eo The names in Martyn's "Universal Conchologist" are not accepted in this report. 

Ralph Arnold recorded this species from his upper San Pedro (The paleontology and 

stratigraphy of the marine Pliocene and Pleistocene of San Pedro, Calif.: California 

Acad. Sci. Mem., vol. 3, p. 328, 1903. ("Phorcus pulligo.") 

67 Perry, George, Concnology, pi. 47, No. 2, 1811 ("Trochus, New Zealand") 

Rehder, H. A., Notes on the nomenclature of the Trochidae: Biol. Soc. Washington 

Proc., vol. 50, p. 116, 1937. 

68 Dillwyn, L. W., A descriptive catalogue of Recent shells, vol. 2, pp. 800-801,1817 

("Trochus"). 

«« Berry, S. S., op. cit., p. 12, pi. 2, figs. 4, 5: 

10 Stewart, Ralph, in Woodring, W. P., Stewart. Ralph, and Richards, R. W., 

Geology of the Kettleman Hills oil field: U. S. Geol. Survey Prof. Paper 195, p. 84/ 

pi. 11, figs. 1, 6,1940 [1941]. 

brevis and caffea in the Kettleman Hills report was 

based on the large Lower California form, which is 

doubtless not T. caffea but closely resembles T. 

imperialis. 

Solariella peramabilis occurs in the Timms Point silt 

(pi. 32, fig. 3) and Lomita marl. Owing to the strong 

axial .threads between the spirals, fragments are identi 

fied with reasonable certainty. The much smaller 

unfigured $. rhyssa n is represented by broken specimens 

from the Lomita marl. It was based on a shell dredged 

in Catalina Channel and has not been reported hereto 

fore as a fossil. 

Pupillaria is generally assigned subgeneric rank under 

Margarites, which, however, is smooth and has a rather 

narrow umbilicus. Lirularia is considered a subgenus 

under Pupillaria. The common Pupillaria of the San 

Pedro district, found in all the Pleistocene units but 

rare in terrace deposits, is identified as P. optabilis. 

It has brownish crudely axial blotches visible on 

fossils, except bleached specimens. The type is a 

Recent shell from San Pedro. This species has prob 

ably been reported as P. parcipicta. The type of P. 

parcipicta from Santa Cruz [Island?! has a higher spire 

and stronger axial threads on the body whorl. Some 

of the fossils, especially some from the Lomita marl, 

have narrow sharp-crested spirals. They are probably 

P. optabilis acuticostata but are not readily differen- 

tiable. .The type of u Margarita" parcipicta var. 

pedroana, based on a worn specimen from the San 

Pedro sand, is considered P. optabilis. Likewise 

"Margarita" optabilis var. nodosa, also from the San 

Pedro sand, is considered P. optabilis, the nodes on the 

type being principally color markings. A large form, 

P. optabilis knechti (pi. 34, figs. 3, 4), is abundant in 

the San Pedro sand, especially at localities 47 and 47a, 

and is identified in the Palos Verdes sand at localities 

112 and 113. The dark blotches cover more of the 

shell than in P. optabilis proper, and as the whorls 

enlarge they tend to flatten. Differentiation on a 

basis other than size is, however, doubtful. Perhaps 

this large form does not deserve nomenclatorial recog 

nition, but it is not know to be living. 72 "Lirularia" 

magna, which like P. optabilis knechti is based on fossil 

material from the San Pedro sand, is a synonym of 

knechti. 

Pupillaria succincta is of the same size as P. optabilis 

and has the same color markings, but the base is 

flatter, and the spirals, which are especially noticeable 

on the base, are more crowded. Found at five localities 

in terrace deposits, this species was not reported 

previously as a fossil. The type material, from an 

undesignated California locality, was collected from 

an abalone. A Timms Point Pupillaria, P. cf. P. 

salmonea, is represented by fragmentary and imma 

ture specimens. It is probably most similar to a form 

dredged off Point Loma at a depth of 71 to 75 fathoms, 

possibly a form of P. salmonea. Another Pupillaria 

from the Lomita marl and San Pedro sand has relatively 

fine spirals on the base, like P. salmonea, but the spirals 

above the base are wider. P. salmonea (type locality, 

Monterey) or forms similar to it are unrecorded as 

fossils. 

The genus Macheroplax is represented by a small, 

imperfect specimen from the Timms Point silt identi- 

71 Dall, W. H.-, Descriptions of new species of Mollusca from the north Pacific 

Ocean in the collection of the United States National Museum: U. S. Nat. Mus. 

Proc., vol. 56, p.- 360, 1919. 

ra According to a recent communication from George Willett, of the Los Angeles 

Museum, his collection from Forrester Island, Alaska, includes four Recent specimens 

of this form.

fiocl as M. cf. M. varitosa. M. varicosa has been re 

corded recently at Timms Point. 73 

LTOTIIDAB 

Two species of Liotid, neither of which has been 

recorded heretofore as a fossil, are rare in the Pleisto 

cene collections. They are L. fenestrata (Lomita marl 

and terrace deposits) and L. acuticostata (terrace de 

posits and Polos Verdes sand). The type of L. fene 

strata, occupied by a hermit crab, is from the "Santa 

Barbara Islands," and most of the other specimens in 

the National Museum are also hermit crab shelters. 

The shells from the Lomita marl are unbroken, whereas 

those from terrace deposits, possibly hermit crab 

shelters, arc broken. The type of L. acuticostata is 

from Cotolino Island. The 1 shell from locality 105 

has a few faint axials, approaching the variety L. 

acuticostata radiata. According to local collectors, both 

L. fenestrata and L. acuticostata appear to be more 

abundant on the islands than on the mainland. 

V1TRINELLTDAE 

Vitrinella thomasi, based on material from the San 

Pedro sand at Oldroyd's Nob Hill locality, is repre 

sented by two specimens from that formation at locality 

48. They are considerably larger than the type (width 

2.7 millimeters). The species is not known to be living. 

V. williamsoni, represented in the National Museum 

only by the type, a Recent shell from San Pedro, is 

much larger (width 5.5 millimeters) and flatter. Arnold 

recorded V. williamsoni from the San Pedro sand and 

Polos Vcrdcs sand without mentioning the size (jr other 

characters. V. oldroydi has been recorded from the 

San Pedro sand 74 and was found in terrace deposits 

at five localities. The umbilicus is much narrower than 

in V. thomaxi and V. williamsoni. V. eshnauri, re 

ported from the San Pedro sand 75 but not in the col 

lections at hand, has a higher spire than the species 

already mentioned. Discovery of the heretofore un- 

figurcd V. salvania 70 (pi. 29, figs. 3-5) in the Lomita 

marl at locality 4.1 constitutes a new record for that 

speHos as o fossil. It has a narrow umbilicus for 

yitrmdla and on one of the three fossils the umbilicus 

is portly closed by a callus plug. The fossils are a 

little larger than the type and only Recent specimen, 

and the umbilicus is slightly wider. V. salvania is 

somewhat intermediate between Vitrinella proper and 

Docom,phala, as the umbilical wall along the apertural 

half of the body whorl is faintly puckered; the spire of 

V. salvania is, however, higher and the early whorls lack 

weak oxiol ribs. 

One specimen of Cyclostremella coronadoensis from 

the Son Pedro sand at locality 49 also constitutes a new 

record for the San Pedro district. The type of that 

species, from the Pleistocene at Spanish Bight, San 

Diego, has not been examined. Six specimens from an 

undes.ign.atcd San Diego Pleistocene locality and several 

hundred from the railroad crossing at the foot of 23d 

Street, San Diego (U. S. G. S. locality 2123), are virtual 

topotypes. 0. californica (type locality San Pedro, 

Recent) is considered a synonym. The type of 

Cyclostremella has a deeper anal sinus adjoining the 

" Wlllott, George, op. clt., p. 03 ("Solariella"). 

» Oklroycl, T. S., Tlio fossils of the lower San Pedro fauna of the Nob Hill cut, 

San 1'otlro, Cnlif.: U. S. Nat. Mus. Proc., vol. 05, art. 22, p. 21,1924. 

" Idem. 

"Pall, W. H., op. clt. (U. S. Nat. Mus. Proc., vol. 56), p. 369, ("Teinostoma 

(J'seudoratella"'); South Coronado Island, 3 fathoms). 


suture than does C. coronadoensis but is otherwise 

similar to that species. 

The genus Pseudorotella is represented by the two 

common California species, P. invallata (San Pedro 

sand, 77 terrace deposits, Palos Verdes sand) and P. 

supravallata (terrace deposits)'. P. supravallata, here 

tofore not recorded as a fossil, is more abundant in 

. terrace deposits than P. invallata. 

TURBINIDAE 

In the absence of the characteristic ribbed operculum, 

adult shells of Pomaulax may be differentiated from 

Pachypoma by the weakly sculptured base. Pomaulax 

undosus occurs in the Lomita marl (pi. 29, figs. 6-8), the 

Timms Point silt (small broken specimen), terrace de 

posits, and the Palos Verdes sand. It is particularly 

abundant in the Lomita marl at Hilltop quarry (locali 

ties 53, 53a). Opercula are as abundant as shells in the 

Lomita marl and were found also in terrace deposits and 

the Palos Verdes sand. This species is generally 

readily distinguishable from Pachypoma gibberosum, 

with which it is associated, by the strong peripheral 

keel and weakly sculptured base. Young shells may 

be difficult to differentiate, however, as young shells of 

both species are keeled and young shells of Pomaulax 

undosus have a more strongly sculptured base than 

adults. 

Pomaulax turbanicus petrothauma 78 (pi. 29, figs. 9-12) 

was found only in the algal bed of the Lomita marl at 

Hilltop quarry, where it is fairly common. It re 

sembles closely the Recent P. turbanicus 79 proper, repre 

sented only by the type dredged off Magdalena Bay 

Lower California, at a depth of,36 fathoms. The 

Pleistocene variety has more widely spaced nodes, and 

the peripheral nodes have a longer base. The figured 

large fossil operculum is rounded like the operculum of 

P. turbanicus proper, and also as in that form has a 

narrow, strongly bent, almost smooth inner rib. The 

fossil operculum (length 29.3 millimeters) is much too 

large to fit any shell at hand and is larger than the 

operculum of the type of P. turbanicus (length 21.8 

millimeters). 

Pachypoma gibberosum 50 ("inaeguale") is found in the 

-three lower Pleistocene units and is recorded from the 

Palos Verdes sand. Like Pomaulax undosus it is most 

abundant in the Lomita marl at Hilltop quarry (pi. 29, 

figs. 13-15), where it is represented by shells and the 

characteristic narrow smooth opercula. The stage at 

which the peripheral keel of fossil and Recent shells 

disappears is variable. In the variety Pachypoma 

gibberosum pacifica the keel persists to an exceptionally 

late, stage. This variety and the unfigured variety 

barbarense 81 are of doubtful validity. 

Four species of the genus Homalopoma are repre 

sented in the Pleistocene collections. The largest and 

most abundant is PI. carpenteri, which has heavy 

relatively widely spaced spirals, except on the early 

whorls of some specimens characterized by a few heavy 

spirals among fine spirals. The rosy color is preserved 

on many fossils. This species is found in all the 

77 Already recorded from the San Pedro sand (Oldroyd, T. S., op. cit., p. 21, 1924 

("Teinostoma"). 

78 Berry, S. S., New Mollusca from the Pleistocene of San Pedro, Calif., I: Bull. 

Am. Paleontology, vol. 25, No. 94a, pi. 10, pi. 2, figs. 2, 3,1940. 

78 The type of P. turbanicus, minus the operculum, has been figured by Grant and 

Gale (Grant, U. S., IV, and Gale, H. R., Catalogue of the marine Pliocene and 

Pleistocene Mollusca of California: San Diego Soc. Nat. History Mem., vol. 1, pi. 31, 

fig. 2,1931). 

soDillwyn, L. W., A descriptive catalogue of Eecent shells, vol. 2, pp. 803-804 

1817 ("Trochus, New Zealand"). 

8" Dall, W. H., op. cit. (U. S. Nat. Mus. Proc., vol. 56), p. 357,1919 (off Santa^Cruz 

Island, 30 fathoms).


units but is most abundant in the Lomita marl, par 

ticularly in the algal bed at Hilltop quarry (pi. 29, 

fig. 16). H. bacula, smaller than H. carpenteri and 

sculptured with finer spirals, occurs in all the units 

except the Palos Verdes sand. As in H. carpenteri, the 

rosy color is preserved on many fossils. H. sub- 

obsoletum,*2 recently described on the basis of material 

from Timms Point, is a minute, faintly sculptured form. 

In the collections at hand it is represented in the 

Lomita marl and doubtfully in the San Pedro sand. 

Specimens (maximum length 2.7 millimeters) dredged 

off Point Loma at depths of 67 to 75 fathoms are identi 

fied as this form. They have faint spiral striae and a 

light-brown color, a little darker than the fossils, as 

Willett inferred. Both the fossil and Recent shells 

have a grooved but not denticulate inner lip, suggesting 

that they are not mature. The readily recognized H. 

paucicostatum,.like H. bacula, occurs in all the units 

except the Palos Verdes sand but is less abundant than 

that species. H. paucicostatum jenestratum, character 

ized by the strengthening of growth threads to form 

ribs, was found in the Lomita marl and terrace deposits. 

This variety has not been recorded heretofore as a 

fossil. It bears the same relation to H. paucicostatum 

that the variety radiata does to Liotia acuticostata. 

TRICOLIIDAE 

Exfoliated specimens of Tricolia that show a wide 1 

umbilicus are likely to be confused with exfoliated 

specimens of Lacuna, but the inner layer of Tricolia 

has faint spiral markings. Fossil Tricolia that retain 

even a small patch of the outer shell layer, presumably 

calcite, are readily, distinguished from Lacuna, as the 

outer layer retains traces of the color pattern. Specific 

differentiation of the fossil Tricoliae is difficult, for 

differentiation of the Recent species is based princi 

pally on size and color pattern. Though fossils retain 

the color pattern, it is bleached.^y^ 

According to the criteria aclopted, Tricolia pulloides 

is the most abundant species in the Pleistocene collec 

tions, being represented in all the units except the Palos 

Verdes sand. It is of medium size (maximum length of 

fossils 5.5 to 5.9 millimeters) and has a mottled rosy 

color pattern; many specimens have oblique dark 

stripes. The best fossils are in the collection from the 

Lomita marl from the central shaft of the Whites Point 

tunnel (locality 57). An operculum that probably rep 

resents this species and a large lot of shells were col 

lected from the San Pedro sand at locality 30. The 

terrace specimens are small, with the exception of a 

large shell from locality 106, where an operculum was 

collected. A lot of 9 Recent shells in the National 

Museum, collected at Santa Barbara by Jewett, is to 

be regarded presumably as the type lot of T. pulloides. 

Tricolia compta is larger and darker colored than T. 

pulloides, Recent shells being greenish and having ob 

lique narrow, brownish bands. The greenish color is 

gone on the fossils identified as T. compta, but traces of 

the brownish bands remain and are well preserved on 

some specimens. The fossils have a maximum length 

of 8.8 millimeters. This species is recognized only in 

the San Pedro sand and Palos Verdes sand. It is par 

ticularly abundant in the San Pedro sand at locality 47a, 

where two isolated opercula were collected. A large 

lot from locality 48 includes a shell with the operculum 

in place. Some small shells from the Palos Verdes sand 

ra Willett, George, op. cit. (Southern Calif. Acad. Sci. Bull., vol. 36), p. 63, pi. 25 

1937 ("Leptothyra"). 

may possibly be T. pulloides. It has been suggested 83 

that Arnold's T. compta from the San Pedro sand and 

Palos Verdes sand is T. pulloides. Arnold's identifica 

tions doubtless agree, however, with those adopted in 

this report. The type lot of T. compta consists of two 

specimens from Sari Diego. 

A minute shell having a naticid spire and open um 

bilicus, collected from deposits on the fourth terrace at 

locality 87, represents the subgenus Eulithidium or pos 

sibly a very young Tricolia pulloides. It is identified 

as Tricolia rubrilineataf . 84 

A small form of Littorina planaxis is abundant in ter 

race deposits, but it is represented at other horizons by 

only one worn specimen from the San Pedro sand and 

two worn specimens from the Palos Ver$es sand. 

Arnold recorded this species from the Timms Point silt. 

The fossils have a maximum length of 9.6 millimeters, 

whereas a large Recent shell from San Pedro has a 

length of 20.8 millimeters. The fossils may represent 

a small race, as it is improbable that several hundred 

shells from 25 localities are all young. It is virtually 

impossible to determine the number of whorls, however, 

for the tip of the spire is generally worn and corroded. 

Littorina scutulata has a more slender spire than L. 

planaxis and lacks the flattened area adjoining the inner 

lip. Both species have spiral striae on at least the early 

whorls. The fossil L. scutulata retain the brownish, 

color more uniformly than L. planaxis. L. scutulata is 

abundant in terrace deposits, being represented in more 

collections than L. planaxis and being generally more 

abundant than that species, except at locality 80. It 

is represented by two very small worn shells in the 

Lomita marl, is fairly common in the San Pedro sand, 

and is common in the Palos Verdes sand. The fossils 

are somewhat smaller than Recent shells, the maximum 

length being 12.6 millimeters as compared with 14.6 

millimeters for a large Recent San Pedro shell. Car 

penter, 85 who had access to the original material, thought 

that L. pedroana, based on Pleistocene material from 

San Pedro, is L. "plena," that is, L. scutulata. The 

type is lost. 

LACUNIDAE 

Many of the fossil specimens of Lacuna are in poor 

condition, owing to exfoliation; furthermore, identifica 

tion of the species is difficult, inasmuch as the charac 

ters of many named Recent forms are still undescribed. 

The common Pleistocene species, found in all the units 

except the Timms Point silt, is identified as Lacuna 

unifasciata. It is small, relatively slender, and nar 

rowly umbilicate and has faint slightly wavy micro 

scopic striae distinguishable only on fresh Recent shells 

and observed on a few of the best preserved fossils. 

Large shells are rounded or carinate; small shells are 

carinate. The carina is generally colored brown, a 

character preserved on some fossils. Arnold's L. 

compacta and Oldroyd's L. unijasciata aurantiaca are 

presumably this species. The type lot of L. unifasciata 

consists of four shells from Santa Barbara, all somewhat 

worn. The largest has a length of 5.7 millimeters and 

83 Strong, A. M., in1 Grant, IT. S., IV, and Gale, H. R., op. cit. (San Diego Soc. 

Nat. History Mem., vol. 1), p. 814,1931. 

M Strong, A. M., West American Mollusca of the genus Phasianella: California 

Acad. Sci. Proc., 4th ser., vol. 17, No. 6, p. 197, pi. 10, figs. 8-10, 1928 (Point Loma). 

86 Carpenter, P. P., A supplementary report on the present state of our knowledge 

with regard to the Mollusca of the west coast of North America: British Assoc. 

Adv. Sci. Kept. 1863, p. 590, 1864.

a width of 3.3 millimeters. Only the smallest shell 

shows the brown band on the carina. 

Lacuna carinata is larger and stouter than L. unifas- 

ciata, the body whorl enlarging more rapidly; the umbil 

ical opening is wider; the microscopic striae are stronger; 

and the inner lip is effuse. It is identified certainly in 

only one collection, the Palos Verdes sand at Arnold's 

Crawfish George's locality (locality 108). It is evi 

dently closely related to the Atlantic L. divaricate,. 

Arnold's L. porrecta and Oldroyd's L. solidula are 

probably this species; if so, it occurs in the San Pedro 

sand. According to topotype material, "Modelia" 

striata 80 from the Pleistocene Santa Barbara formation 

at Santa Barbara is Lacuna carinata, as Carpenter 87 

thought. The two specimens in the type lot of L. 

carinata from Puget Sound were figured by Gould. 

The larger specimen (fig. 231; length 11 millimeters and 

width 5.8 millimeters), which is not so distinctly cari- 

nato as in the .illustration, appears to be exceptional or 

pathologic, as the body whorl does not enlarge and the 

umbilicus is reduced to a very narrow opening. The 

smaller specimen (figs. 23la, 23Ib; length 6.9 milli 

meters, width 4.4 millimeters) is normal but immature 

and is faintly carinate. L. porrecta, based on material 

collected by Swan at Neah Bay at the mouth of the 

Strait of Juan de Fuca, is considered a synonym of 

L. carinata. A faintly carinate specimen, collected by 

Swan at Neah Bay but received through Stearns, has 

been figured 88 as the type of L. porrecta. It may be 

regarded as the lectotype, as it was probably in the 

lot examined by Carpenter. Forty-five additional 

specimens collected by Swan at Neah Bay are in the 

collection of the National Museum. 

Lacuna variegata 80 has a wide umbilical opening and 

effuse inner lip like L. carinata but is more slender and 

has less distinct spiral striae and brown chevrons on the 

body whorl. Its status is not satisfactorily determined. 

The typo lot, like the type material of L. porrecta, 

collected by Swan at Neah Bay, consists of 23 speci 

mens, the largest having a length of 8.5 millimeters and 

a width of 5 millimeters. One specimen from the 

Lomita marl at locality 53a and a few specimens from 

the Palos Verdes sand at localities 109 and li2 are 

identified as L. variegata?. They resemble L. carinata 

but are more slender. The color pattern is not pre 

served. Arnold's figured L. solidula is exfoliated and 

unidentifiable on the basis of the illustration. It may 

be the form identified in this report as L. variegata?. 

FOSSARIDAE 

Iselica fenestrata occurs in all the units except the 

Timms Point silt but is rare except in the collection 

from the San Pedro sand at locality 47a (pi. 34, fig. 5). 

In Oldroyd's Nob Hill collection from that formation it 

is represented by an extraordinarily large number of 

specimens. 

VALVATIDAE 

The fresh-water gastropod Valvata humeralis cali- 

Jornica, heretofore unrecorded from the San Pedro 

" Oabb, W. M., Descriptions of new species of American Tertiary fossils and a 

new Carboniferous cophalopocl from Texas: Acad. Nat. Sci. Philadelphia Proc.. 

vol. 13, p. 368,1861 ("Miocene?"). 

" Carpenter, P. P., op. cit. (British Assoc. Adv. Science Rpt., 1863), p. 632,1864. 

«> Dall, W. H., Summary of the marine shell-bearing mollusks of the northwest 

coast of America: U. S. Nnt. Mus. Bull. 112, p. 216, pi. 14, fig. 2,1921. 

' Carpenter, P. P., op. cit., p. 656. 


district, is represented by one specimen from the Palos 

Verdes sand at locality 114. 

KISSO1DAE 

The genus Amphithalamus , 9D heretofore unrecorded in 

the fossil state, embraces minute shells less than 2 

millimeters in length. A. inclusus, the type of the 

genus, is rare in the Lomita marl and San Pedro sand 

(localities 53a, 140). The periphery is angulated or 

has a low spiral cord. Minute shells (length a little 

more than a millimeter) from the Lomita marl at 

locality 42d are identified as "Amphithalamus" lacun 

atus?. They agree with the type of lacunatus, a 

Recent shell from San Pedro, in having a narrow 

umbilical groove, no basal fasciole, and an undetached 

peristome along the parietal wall. Some of the fossils, 

however, do not enlarge so rapidly as the type and only 

available Recent specimen. Most of the fossils are 

exfoliated and therefore have a misleading deeply 

sunken suture. The absence of a fasciole and of a 

detached peristome along the parietal wall indicates 

that lacunatus is not assignable to Amphithalamus. 

Alvania, as currently used for west coast mollusks, 

is represented by four species and a variety. A. 

acutelirata 91 is found in all the units except the Timms 

Point silt but is generally'rare. It is relatively slender 

and has reticulate sculpture, except on the base, which 

has only spirals, the axials overriding the spirals. In 

the original description the general region between San 

Diego and San Pedro was cited. In the 1866 account 

the only locality mentioned is San Diego, which there 

fore is considered the type locality. The type material 

is not in the collection of the National Museum. A. 

pedroana, based on 2 fossils from San Pedro,, evidently 

from the San Pedro sand, is considered a synonym of 

A. acutelirata. These two specimens have a channeled 

suture and almost flat whorls. Some Recent and fossil 

specimens of A. acutelirata have a channeled suture, 

depending on whether the axials stop at a spiral just 

above the base of a spire whorl. The degree of infla 

tion of the whorls of Recent and fossil shells is van-able, 

some being as flat as A. pedroana. 

Alvania rosana is considered a stout form of A. 

acutelirata. On adult shells the sculpture generally 

fades out on the body whorl near the outer lip. This 

feature was observed, however, on some slender fossils 

identified as A. acutelirata proper. Fossils from the 

three lower Plesitocene units and the Palos Verdes 

sand are identified as A. acutelirata rosana. This form 

is widespread in the Lomita marl and locally is excep 

tionally abundant in that unit. It is estimated tha't 

the collection from locality 53b includes more than 

1,000 specimens, which is more than the total number 

of Recent Pacific coast Alvania in the collection of the 

National Museum. The fossils have more closely 

spaced ribs than the type of the variety rosana and 

other specimens from the same dredging (Albatross 

station 2901, oft" Santa Rosa Island, 48 fathoms). 

Some specimens from a nearby dredging (Albatross 

station 2902, off Santa Rosa Island, 53 fathoms) have 

ribs as closely spaced as on the fossils. A. acutelirata 

rosana is associated with A. acutelirata proper in the 

Lomita marl, San Pedro sand, and Palos Verdes sand. 

80 For a description of the California species see Bartsch, Paul, The west American 

mollusks of the genus Amphithalamus: U. S. Nat. Mus. Proc., vol. 41, pp. 263-265 

3 figs., 1911. 

" Carpenter used the spelling "acutelirata" in the original description (Carpenter 

P. P., op. cit., p. 656,1864; "Rissoa") and in a later work (Descriptions of new marine 

shells from the coast of California; pt. 3: California Acad. Sci. Proc., vol. 3, p. 217 

1866; "Rissoa"). The generally adopted alteration "acutilirata" is unwarranted.


Inasmuch as some lots contain intermediate doubtful 

specimens, the identifications are doubtful. A.fossilis, 

based on a fossil shell from San Pedro, evidently fiom 

the San Pedro sand, is considered.a synonym of A. 

rosana. The whorls are a little flatter than on most 

Recent and fossil shells, but that character is variable. 

Alvania montereyensis was found at three terrace 

localities. It is slender and has strongly constricted 

sutures, and well-preserved Recent shells have faint 

spiral sculpture on the nucleus. Oldroyd found this 

species.to be abundant in the San Pedro sand at Nob 

Hill. It is the type of Willettia, proposed recently as a 

subgenus of "Alvania" by Gordon, 92 according to whom 

the Pacific coast species referred to Alvania are not 

congeneric with the Mediterranean species that is the 

type of that genus. 

The other two species of Alvania have not been 

recorded heretofore as fossils in the San Pedro district. 

A. purpurea has a somewhat turreted spire, two or 

three spirals on spire whorls, and strong axials that 

form swellings at the intersection with spirals on un 

worn shells. It is rare in the Lomita marl and terrace 

deposits. A. almo is represented by two terrace 

specimens. This minute species has a thickened outer 

lip, but the peristome is in one plane, not. undulatory 

as in Rissoina. 

The Pleistocene specimens of the minute genus 

Barleeia, found in all the units but most abundant in 

the Lomita marl and terrace deposits, are identified 

as B. haliotiphila. More than one species, however, 

may be represented." The shells are variable in length, 

degree of slenderness, degree of whorl inflation, and 

degree of rounding of the periphery. None of the 

several hundred fossils are as large as the type of B. 

oldroydi (length 3.3 millimeters). Stout shells are 

similar to B. californica, which has more inflated whorls. 

The faint color banding generally visible on B. cali 

fornica would presumably be indistinguishable on 

fossils. The pits on the nuclear whorls described by 

Bartsch 93 are so minute and so faint that they are 

generally indistinguishable under high magnification, 

even on specimens that ordinarily would be considered 

quite fresh. Both B. haliotiphila 94 and B. oldroydi 9S 

have been recorded from the Timms Point silt. 

RISSOINIDAE . . 

Five species of the genus Rissoina are represented in 

the Pleistocene collections, whereas Arnold recorded 

none. Rissoina kelseyi has sharply incised spiral striae 

and heavy ribs that fade put on the penultimate and 

body whorls. It occurs in the Lomita marl (pi. 29, 

fig. 17) and in deposits on the second terrace at Malaga 

Cove (locality 105). The two specimens from- the 

Lomita marl at locality 42d have slightly heavier ribs 

and more inflated whorls than Recent shells and the 

other fossils. The terrace fossils consist of a lot of 35 

specimens, including very young shells. The spiral 

striae are very faint on the terrace shells, though most 

are quite fresh, and on some the axials persist on the 

penultimate whorl. 

Rissoina pleistocena, not heretofore recorded from 

the San Pedro district, was found in deposits on the 

" Gordon, Mackenzie, Jr., A new subgon us and species of west coast "Alvania": 

Nautilus, vol. 53, p. 31, 1936.' ' " 

" Bartsch,' Paul, The west American mollusks of the families Rissoellidae and 

Synceratidae and the rissoid genus Barleeia: U. S. Nat. Mus. Proc., vol. 58, pp. 

167-376, 1920. 

e< Clark, Alex, op. ci't. (San Diego Soc. Nat. History Trans., vol. 7, No. 4), table 

op. p. 30, 1931. 

«« Willctt, George, op. cit. (Southern California Acad. Sci. Bull., vol. 367), p. 62, 

1937. 

second terrace at Malaga Cove at locality 105 and in 

the Palos Verdes sand at locality 140 (pi. 35, fig. 8). 

It is stout and has heavy slightly protractive ribs. It 

is not known to be living but is related to the Mexican 

R. nereina and R. burragei, though it has heavier and 

more widely spaced ribs. R. coronadoensis, a slender 

species sculptured with very fine axial ribs, occurs in 

the Lomita marl (pi. 29, fig. 18), Timms Point silt, and 

San Pedro sand. Perhaps the records of the more 

strongly sculptured R. dalli in the Timms Point silt 96 

and San Pedro sand refer to R. coronadoensis. 

Rissoina aequisculpta has a somewhat turreted spire, 

strong reticulate sculpture, and spiral sculpture on the 

nucleus. It is represented by an incomplete specimen, 

showing the sculptured nucleus, from the Lomita marl 

at locality 53a and is recorded from the San Pedro 

sand. The minute R. cosmia, which has a turreted 

spire and strong reticulate sculpture, is represented by 

a broken specimen from terrace deposits at locality 84. 

It has not been, recorded heretofore as a fossil. Both 

R. aequisculpta and R. cosmia have been assigned to 

Alvania*7 The characters of the lip in both species 

suggest, however, Rissoina. 

TRUNCATELLIDAE 

Both Truncatella stimpsoni and T. californica are 

identified in collections from terrace deposits, the 

former being more abundant. T. stimpsoni is stouter 

than T. californica and is generally strongly sculptured, 

whereas T. californica is usually smooth or almost 

smooth. T. californica has been recorded from the San 

Pedro sand, but T. stimpsoni has not heretofore been 

recorded from the San Pedro district. 

SYNCERIDAE 

Syncera translucens occurs in terrace deposits and is 

recorded from the San Pedro sand. This marine 

species may be distinguished from the fresh-water 

amnicolids by the relatively thick parietal callus. 

AMNICOLIDAE 

An imperfect specimen of the stout fresh-water 

Amnicola longingua was collected from the Palos 

Verdes sand at locality 120. This species was based 

on material collected from sediments of ancient Lake 

Cahuilla in the Colorado Desert. It is living in 

southern California. The finding of A. longingua in 

the Palos Verdes sand constitutes a new record for the 

San Pedro district. 

Hydrobia protea, another fresh-water species, was 

found in the San Pedro sand at locality 47a and in the 

Palos Verdes sand at locality 113. Like Amnicola 

longingua, Hydrobia protea was based on material from 

ancient Lake Cahuilla. It ajso is living in southern 

California. As its name implies, it is very variable. 

In sculpture the range is from smooth to strongly 

reticulate; in outline from slender, the usual form, to 

moderately slender. The fossils from the San Pedro 

district are smooth or faintly sculptured. Paludes- 

trina curta, gs based on fossils from San Pedro, is a 

moderately slender form of H. protea. The type shows 

faint spiral sculpture. Paludestrina stokesi, also 

»e Clark, Alex, op. cit. (San Diego Soc. Nat. History Trans., vol. 7, No. 4), table 

op. p. 30,1931. 

" Bartsch, Paul, The Recent and fossil mollusks of the genus Alvania from the 

west coast of America: U. S. Nat. Mus. Proc., vol. 41,,pp. 352, 358, 1911. 

as Arnold, Ralph, op. cit. (California Acad. Sci. Mem., vol. 3), p. 305, pi. 8, fig. 2, 

1903. 

»«Idem, p. 305, pi. 8, fig. 3.

ased on fossils from San Pcdro, is a slender form and 

has faint spirals on< the early whorls. Oldroyd 1 re 

corded Ifydrobia protea as Paludestrina curia and 

Paludestrina cf. P. stokesi. Alabina io also is considered 

a synonym of Uydrobia protea. It was described on 

the basis of a worn fossil from San Pedro that shows 

subdued axial and faint spiral sculpture. The drawing, 

therefore, is misleading. The Pleistocene fossils from 

a locality near Playa del Rey' recently recorded as 

lUssocUa sp.? 2 are likewise considered as representing 

slender Hydrobia protea. 

ALABINIDAE 

Alabina tenuisculpla is represented by a young speci 

men from the Palos Vcrdcs sand at locality 140 and is 

recorded from the San Pedro sand. 3 The sculpture 

of this species is evidently variable. The type, from 

San Diego, has only two widely spaced spirals on the 

spire whorls. A form that has many fine spirals and 

relatively weak axials has been named A. diegensis. 

The slender, slowly enlarging nucleus and slight ever- 

sion. of the basal lip support assignment of A. tenuis- 

culpta to the genus Alabina, despite the absence of 

varices. The type species of Alabina has weak varices 

or none, but oi.li.erw.ise similar species have strong 

varices. 

The systematic position of the California shells 

assigned to the genus Viola is uncertain. The varix on 

the body whorl near the outer lip and the slight ever- 

sion of the basal lip suggest the family Alabinidae, 

but the nucleus is much stouter than in Alabina and 

the shell is heavier. It is improbable that the Cal 

ifornia Diala is related to Barleeia, with which it is 

generally placed. It is not known whether the Cal 

ifornia shells are congeneric with the Chinese and 

Japanese Diala. 4 Japanese specimens in the National 

Museum, labeled Diala varia have a similar aperture 

but lack the varix and. have spiral sculpture on the base 

of the body whorl. 

Fossils from the Lomita marl, San Pedro sand, terrace 

deposits, and Palos Vcrcles sand are identified as Diala 

marmorea, and that species is recorded from the Timms 

Point silt. 5 The best specimens and the largest number 

are from terrace deposits at locality 96. It is doubtful 

whether more than one species of this genus is living 

along the, California coast. The type of D. marmorea 

from. San Pedro is relatively stout and has a rounded 

periphery; the typo of D. acuta from Catalina is more 

slender and has an angulated periphery; and the type 

oi" Barleeia" dalli from Point Loma (7.1 to 75 fathoms) 

is stout and has an angulated periphery. Some speci 

mens arranged under D. marmorea in the collection of 

the National Museum, have an angulated. periphery; 

some arranged under D. acuta, have a rounded periph 

ery. Not all the specimens in the lot from which the 

type of "Barleeia" dalli was selected are as sharply 

angulated as the type, and two specimens from the 

' Oldroyd, T. S., op. cit. (U. S. tfat. Mus. Proc., vol. 65, art. 22), p. 17, 1924. 

8 Willott, OcorL'o, An upper Pleistocene fauna from the Baldwin Hills, Los Angeles 

County, Calif.: Kan Diego Soc. Nat. History Trans., vol. 8, No. 30, p. 398, 1937. 

Arnold, Ralph, op. cit. (California Acad. Sci. Mem., vol. 3), p. 296, pi. 6, flg. 14 

1003 ("Bittium (Styliferina)"; unrecognizable on basis of figure). 

4 Adams, A., On some now genera and species of Mollusca from the north of China 

and Japan: Ann. Mag. Nat. History, 3d ser., vol. 8, p. 242, 1861. Subsequently 

designated typo (Cossmann, M.. Essais do palooconchologie comparee, pt. 12, p. 66, 

1021), Diala varia A. Adams, China and Japan. 

8 Clark, Alox, op. cit. (San Diego Soc. Nat. History Trans., vol. 7, no. 4), table op. 

p. 30, 1031. 


same dredging, evidently, the same form, are arranged 

under Diala acuta. 

CERITHIIDAE 

The Pleistocene specimens of the genus Bittium are 

difficult to identify, owing to the extraordinary number 

of specimens, the rather variable characters, and the 

great number of names that have been proposed with 

out adequate consideration of the range of variation. 

Six species and a variety are identified. On a basis 

of nuclear characters two groups are recognized. One 

group (B. eschrichtii, B. rugatum, and B. rugatum 

larum) has stout rounded nuclear whorls; the other 

group (B. armillatum, B. attenuatum, B. interfossa, and 

B. asperum) has an angulation at the upper edge of 

the nuclear whorls, the angulation reaching its maxi 

mum development in B. asperum. The angulation 

may be regarded as a spiral; a second spiral is introduced 

below the periphery, either on the nucleus or at the 

transition between nuclear and postnuclear whorls. 

The subgeneric name Stylidium has been proposed for 

a species of the first group (7?. eschrichtii}, and the 

subgeneric name Lirobittium for a form of the second 

group (B. catalinense}. It is improbable, however, 

that. 7?. rugatum is closely related to B. eschrichtii. 

The relations of B. rugatum to the Eocene Semibittium, 

to which it is currently assigned, are unknown. B. 

guadrifilatum has not been recognized among" the 

fossils. Arnold's B. guadrifilatvm is evidently B. 

attenuatum. Arnold's phylqgenetic series 6 included 

species of diverse affinities. 

Bittium eschrichtii is represented in terrace deposits 

by a worn specimen from the Palos Verdes sand at 

locality 107 and is recorded from the San Pedro sand. 

The best lot, including small shells that show the nu 

cleus, is from terrace deposits at locality 87. This species 

is large, stout, (Joniobasis-like and is sculptured with 

flat spiral bands separated by narrower interspaces. 

It is the most distinctive of the fossil species of the 

genus from the San Pedro district. The fossils are 

presumably B. eschrichtii montereytMsis, but the charac 

ters cited to differentiate that subspecies are unrecog 

nizable in somewhat worn fossils. 

The most abundant Bittium in the Lomita marl 

(pi. 29, fig. 19) and Timms Point silt is identified as 

B. rugatum. It is less abundant in the San Pedro 

sand, relatively rare in the Palos Verdes sand, and was 

not recognized in collections from terrace deposits. 

The Palos Verdes specimens are generally broken and 

worn. More specimens are in the collection from 

Arnold's Crawfish George's locality (locality 108) than 

.in any other collection from the Palos Verdes sand. 

The type of B. rugatum is from the lower Pleistocene 

Santa Barbara formation at Santa Barbara. The 

sculpture is variable but consists of strong axials and 

spirals. The axials are wide, closely spaced, and 

strongly curved on the later whorls. The spirals are 

slightly swollen on the crest of the axials. Secondary 

spirals of varying strength are present but may be 

absent or subdued on the later whorls. An exception 

ally large coarsely sculptured Pleistocene form from 

San Diego has been named B. giganteum. None of the 

fossils from the San Pedro district are quite so large, 

but some have comparable sculpture. B. subplanatum 

and B. serra appear to be southern living representa 

tives of B. rugatum. For the most part the Recent 

shells are smaller and have finer sculpture. Some large 

Arnold, Ralph, op. cit. (California Acad. Sci. Mem., vol. 3), pp. 293-294, 1903


coarsely sculptured shells from southern California, 

arranged under Tachyrhynchus in the collection of the 

National Museum, appear to be indistinguishable from 

Bittium rugatum. Typical representatives of the north 

ern genus Tachyrhynchus have a wider and less pro 

nounced canal than Bittium. In the absence of opercula, 

differentiation of these two genera may, however, be 

difficult. 

Fossils that are generally smaller and more slender 

than Bittium rugatum proper and that have fewer, more 

widely spaced, and straighter axials are identified as 

B. rugatum larum. This form is abundant in the 

Lomita marl (pi. 29, fig. 20) and Timms Point silt, is 

rare in the San Pedro sand, is represented b\r a worn 

broken terrace specimen, and is not recognized in the 

Palos Verdes sand. The type of B. rugatum larum is 

from San Pedro Bay. The few Recent shells available 

are shiny and polished, and many of the fossils have a 

similar appearance. This form may be a distinct 

species; among the fossils, however, it appears to inter- 

grade with B. rugatum proper. 

Bittium armillatum is the only form of the genus 

recognized in all the Pleistocene units. It is generally 

rare in the Lomita marl, very rare in the Timms Point 

silt, very abundant in the San Pedro sand (pi. 34, fig. 6), 

widespread but not common in terrace deposits, and 

relatively rare in the Palos Verdes sand. This species 

has coarse reticulate sculpture, the spirals being beaded 

on the crest of the axials. The type (lectotype?) is a 

worn broken Pleistocene fossil from Santa Barbara col 

lected by Jewett. A better specimen, also a Santa 

Barbara fossil collected by Jewett, arranged under 

B. ornatissimum in the collection of the National 

Museum, is doubtless the same species. The type 

material of B. ornatissimum is from Deadman Island, 

presumably from the San Pedro sand, and represents 

the species identified in this report as B. armillatum. 

B. armillatum proper is not known'to be living, speci 

mens from San Pedro in the National Museum collec 

tion being doubtless detrital fossils. B. purpureum 

(type locality, Monterey) appears to be a small Recent 

form of B. armillatum. The specimen from the type 

lot figured by Bartsch 7 has a somewhat turreted spire, 

but the other three specimens do not. Despite its 

name, the type of B. catalinense also is a fossil from 

Santa Barbara. It has the same kind of sculpture as 

B. armillatum. The nucleus is more strongly angulated 

by a spiral at the upper edge, the spiral near the base 

begins at an earlier stage, and the axials begin at a 

later stage. It is doubtful, however, whether this form 

deserves nomenclatorial recognition. The Recent shells 

from Catalina arranged under B. catalinense have a 

nucleus like the type, but the axials begin at an earlier 

stage, as early as in B. armillatum. These Recent shells 

are more slender than the type of B. catalinense and of 

B. purpureum, and the axials are weaker and farther 

apart; that is, the sculpture is less strongly reticulate 

Bittium attenuatum is a readily recognized small 

slender species sculptured with relatively weak axials 

and overriding spirals. The sculpture is subdued on 

the later whorls, the spirals being more persistent than 

the axials. Recognized in all the Pleistocene units 

except the Timms Point silt, it is less abundant than 

B. armillatum. The specimen from the type lot of two 

figured by Bartsch 8 is chosen as the lectotype. It is 

presumably from Monterey. 

' Bartsch, Paul, The Recent and fossil mollusks of the genus Bittium from the 

west coast of America; U. S. Nnt. Mus. Proc., vol. 40, p. 391, pi. 52, fig. 3, 1911. 

8 Bartsch, Paul, op. cit., p. 393, pi. 54, fig. 5. . 

Bittium interjossa, rare in the Lomita marl and ter 

race deposits, is unrecorded as a fossil from the San 

Pedro district. It is Rissoina-like and has a somewhat" 

turreted spire, coarse reticulate sculpture coarser than 

the other fossil species and a heavy basal spiral. The 

type is a worn shell from Catalina. 

Bittium asperum is common in the Lomita marl, rare 

in the San Pedro sand, is represented by a fragment 

from the Palos Verdes sand, and is recorded from the 

Timms Point silt. 9 Both young and adult shells are 

readily recognized. The nucleus is so strongly carinate 

at the upper edge of the whorl that it appears to be 

broken. The spirals are weak, especially between the 

axials, and shelflike, only the upper edge projecting at 

right angles to the whorl. The type is a Pleistocene 

fossil from Santa Barbara. Perhaps the Recent form 

B. asperum lomaense (type locality, off Point Loma, 

71-75 fathoms) can be differentiated by its somewhat 

smaller size and less sharply angulated nucleus. 

The new generic name Elassum is proposed for 

"Bittium (Elachista}" californicum (pi. 29, fig. 21). 

The preoccupied name Elachista was used inadver 

tently for that species. 10 It is not congeneric with the 

Floridian and West Indian "Bittium" cerithidioide, 

which was intended as the type of Elachista and is the 

type of Alabina, proposed as a substitute for Elachista. 

Elassum is more Bittium-like than Alabina; it has a 

larger, heavier shell, stouter nucleus, coarser sculpture, 

and a more strongly channeled basal lip. The nucleus 

is stouter than in Bittium, and the spiral sculpture 

consists of only a few finely engraved striae. Elassum 

is not known to be living and so far as known is mqno- 

typic. It would not be surprising to find it living, 

however, in moderately deep water off the coast of 

southern California. The porcelanepus, polished, and 

finely engraved shells of Elassum californicum are quite 

distinctive. They are abundant in the Lomita marl 

and rare in the Timms Point silt and San Pedro sand. 

The type is from Deadman Island, presumably from 

the San Pedro sand. 

Cerithidea californica, which lives on tidal flats, is 

locally abundant in the Palos Verdes sand at locality 

111 and other localities farther north and northwest. 

Though recorded from the Timms Point silt of Dead 

man Island, it was not found in that unit or the Lomita 

marl. It occurs in the San Pedro sand at localities 48, 

49, and 49a. 

CEHTHIOPSIDAE 

The genus Cerithiopsis is represented by a small 

number of specimens but apparently by at least eight 

species. Unless the material is reasonably complete, 

identification is difficult. The species are readily classi 

fiable into major groups on the basis of nuclear charac 

ters, as emphasized by Bartsch. C. fatua (Lomita 

marl; type from San Pedro sand) is considered a 

Pleistocene form of the Recent C. pedroana. The fos 

sils are a little more slender than Recent shells, and the 

axials are fewer and farther apart; the nucleus is 

slender and smooth. According to Arnold's illustra 

tion, C. williamsoni (type froin Palos Verdes sand) 

appears to be a stout Pleistocene form of the Recent 

C. berryi. It is recognized in several terrace collec 

tions. C. cosmia, not heretofore recorded from the San 

9 Clark, Alex, op. cit. (San Diego Soc. Nat. History, vol. 7, No. 4), table op. p. 30, 

1931. 

10 For discussion and citations see Woodring, W. P., Miocene mullosks from Bow- 

den, Jamaica, part 2, Gastropods and discussion of results: Carnegie Inst. Wash 

ington Pub. 385, pp. 338-339, 1928.

Pedro district, is recognized in the three lower Pleisto 

cene units and in terrace deposits. Some of the fossils 

show the slender nucleus sculptured with very fine 

curved axial riblets. Without the nucleus it is diffi 

cult to distinguish y6ung shells of C. cosmia from young 

shells of C. pedroana fatua, which have somewhat more 

inflated whorls. C. antemunda is represented by a 

specimen from the San Pedro sand. It is probably 

the species recorded from that unit as C. diegensis, u a 

species that has more closely spaced axials. The mod 

erately stout nucleus, sculptured with axials and spirals, 

is preserved on the fossil. C. necropolitana was based 

on material from the San Pedro sand at Deadman 

Island and is not known to be living. In the collections 

at hand it is represented in the Lomita marl. Some of 

the fossils show the stout nucleus sculptured with 

heavy curved axial ribs. Fragmentary material from 

the Lomita marl and Timms Point silt appears to be 

similar to the Recent C. gloriosa. Worn or broken 

specimens from terrace deposits and the Palos Verdes 

sand are identified as C. arnoldi fossilis, the type of 

which is a worn incomplete shell from the San Pedro 

sand of Deadman Island. The Pleistocene form is 

larger than the Recent C. arnoldi and has coarser 

sculpture. Neither form is, however, well known. 

Though the name fossilis has page precedence, arnoldi 

is arbitrarily given precedence, because it is based on 

Recent material. 

An incomplete large slender shell that has constricted 

whorls, coarsely reticulate sculpture, and axials that 

are exceptionally far apart was collected from the 

Lomita marl at locality 53a. If it is a Cerithiopsis, as 

appears probable, it is a new species. Two incomplete 

specimens from the Lomita marl at locality 71 repre 

sent a Bittium-]\ke Cerithiopsis unlike any species 

known to be living on the California coast. This form 

closely resembles the Recent C. willetti from Alaska. 

The two specimens are a little more slender than the 

type of C. willetti, the axials are narrower and farther 

apart, and the spirals are a little wider. Two other 

Recent specimens of C. willetti show, however, some 

variation in these characters. The nucleus of C. 

willetti is like that of C. necropolitana. It "is not pre 

served on the fossils. 

TmrilORIDAE 

Triphora pedroana is recognized in several terrace 

collections and in a Palos Verdes collection and is 

recorded from the, Timms Point silt. 12 The Palos 

Verdes specimen is exceptionally large (length 8.6 

millimeters). Specimens from the Lomita marl are 

identified as T. cf. T. pedroana. They taper less 

rapidly than pedroana. The recently described Timms 

Point species T. jossilis 13 is characterized by a faint 

median spiral introduced at a late stage. 

VERMETIDAE 

" Vermetus" nodosus, from the San Pedro sand, may 

be the smooth variety of Aletes squamigerus. Speci 

mens from the San Pedro sand at locality 47a show 

swellings similar to those of nodosus but are not " septate 

within," as described by Oldroyd. Two large thick 

almost straight tubes collected from the Lomita marl 

in the central shaft of the Whites Point tunnel resemble 

Oldroyd, T. S., op. cit. (U. S. Nat. Mus. Proc., vol. 65, art. 22). p. 15, 1924. 

"WilloW, Qcorgo, op. oit. (Southern California Acad. Sci. Bull., vol. 36), p. 62, 

1937. 

« Willott, Qoorgo, op. cit., p. 62, pi. 24. 


tubes of the mud-boring pelecypod Kuphus. They are 

identified as the smooth variety of Aletes squamigerus, 

as one shows the flattened attachment area. 

The small strongly sculptured contorted tubes of 

" Vermetus' 1 anellum are readily recognized. Found in 

all the Pleistocene units except the Palos Verdes sand, 

this species is unrecorded as a fossil from the San Pedro 

district. 

CAECIDAE 

Caecum californicum (Lomita marl, San Pedro sand, 

terrace deposits, and Palos Verdes sand), Micranellum 

crebricinctum (all units), and Fartulum occidentale 

(San Pedro sand, terrace deposits, and Palos Verdes 

sand) are recorded already from the San Pedro district. 

In addition, Caecum grippi is represented by a speci 

men from the* Lomita marl and Fartulum orcutti from 

terrace deposits. Caecum grippi has a few coarse 

annuli, about 15, that are far apart. According to 

Arnold's figure, his Caecum magnum is probably the 

young of Micranellum crebricinctum a conclusion 

reached by Willett. 14 Oldroyd's Fartulum hemphilli is 

considered F. occidentale. F. orcutti is a short stout, 

species that has a very oblique somewhat contracted 

aperture. 

TURRITELLIDAE 

Two species of the genus Turritella are represented in 

the Pleistocene strata T. pedroensis and T. cooperi. 

T. pedroensis is locally abundant in the Lomita marl 

(pi. 29, figs. 22, 23) and Timms Point silt (pi. 32, fig. 4), 

is less abundant in the San Pedro sand (pi. 34, .fig. 7), is 

represented by two worn, broken specimens from de 

posits on the third terrace at Hilltop quarry (locality 

93), and by a -worn, broken specimen in each of two 

Palos Verdes collections (localities 120, 140). T. cooperi 

is abundant in the Lomita marl, more abundant in the 

Timms Point silt, is common in the San Pedro sand 

(ph 34, fig. 8), and is widespread in the Palos Verdes 

sand (pi. 35, fig. 9) but is abundant in that unit only at 

Arnold's Crawfish George's locality (locality 108), where 

the specimens are worn. Adult shells of the two species 

are readily distinguishable, T. pedroensis having a larger 

apical angle, less constricted suture, and heavier spirals. 

Tips are not so readily distinguishable, as the develop 

ment of the sculpture is similar; tips of T. pedroensis 

have generally, however, a larger apical angle. The 

two species are associated at numerous localities, but 

both are abundant only at localities 32c (Timms Point 

silt) and 30 (San Pedro sand). 

The recently described Turritella pedroensis 15. is the 

species for which Arnold used the name T. jewettii. 

The material on which Carpenter based T. jewettii was 

from a locality inland from Santa Barbara. The type 

material has not been found in the-Jewett collection at 

Cornell University. 16 A small incomplete specimen in 

the collection of Recent California mollusks in the Na 

tional Museum (19827; length' 15.1 millimeters, width 

5.8 millimeters) labeled " Turritella jewettii Cpr., Santa 

Barbara, Jewett-Gabb (also fossil)," evidently was 

'examined by Carpenter, as the handwriting of the entry 

in the catalog book is identified by Dr. Paul Bartsch as 

Carpenter's. It is not certain, however, that this speci 

men is a fossil or that it was in Carpenter's original ma- 

" Willett, George, op. cit. (San Diego Soc. Nat. History Trans., vol. 8, No. 30), 

p. 399,1937. 

is Applin, E. R., in Merriam, C. W., Fossil Turritellas from the Pacific Coast re 

gion of North America: California Univ., Dcpt. Geol. Sci., Bull., vol. 26, pp. 121-123, 

pi. 35, figs. 1-9, 1941. 

" Merriam, C. W., idem, p. 122, footnote.


terial. That Carpenter had only a small shell or shells 

is indicated by his description of the sculpture of only 

the young shell ("t. jun."). The small specimen in the 

National Museum is large enough to indicate that it is 

not the flat-whorled T. jewettii of Arnold; it is doubtless 

T. cooperi, forms of which are the only representatives 

of the genus found at localities near. Santa Barbara. 

In view of the uncertain status of T. jewettii, it appears 

to be preferable to use Applin's name for the species 

from the Pleistocene strata of the San Pedro district. 

As shown by the illustrations, the strength of primary 

and secondary spirals of Turritella pedroensis is variable. 

Specimens from the San Pedro sand of Deadman Island 

at locality 30, one of which is figured (pi. 34, fig. 7), 

show diffused brownish blotches. This species is one 

of the few well-defined Pleistocene species of the San 

Pedro district that is not known to be living. Arnold 

thought it was extinct, and, despite published range 

lists to the contrary, its occurrence asâ Recent species 

has not been confirmed. The Pliocene specimens 

from a well in San Diego identified by Dall as T. jewettii 

represent forms of T. cooperi. The few worn specimens 

of T. pedroensis from late Pleistocene terrace deposits, 

including the Palos Verdes sand and strata at Playa del 

Rey 17 correlated with the Palos Verdes sand, may pos 

sibly be detrital material. 

The sculpture of Turritella cooperi is very variable. 

Specimens from the Palos Verdes sand (pi. 35, fig. 9) are 

more strongly sculptured than others. Those that 

have subdued nodes on the spirals, like the figured 

Palos Verdes shell, resemble the recent T. mariana 

(type locality near Tres Marias Islands, 80 fathoms), 

but that species is more slender and has two strong 

spirals on the early whorls. Shells from the San Pedro 

sand at Deadman Island (locality 30) have diffused 

brownish blotches, like Recent shells but lighter (pi. 

34, fig. 8). 

HIPPONICIDAE 

The two species of Hipponix, H. antiquatus and H. 

lumens, are most abundant in terrace deposits, H. 

antiquatus being the more abundant. H. antiquatus is 

represented also by one specimen from the Lomita marl 

(locality 61) and by one specimen from each of two 

Palos Verdes collections (localities 107, 108) and is 

recorded from the Timms Point silt and San Pedro 

sand. H. tumens is represented in the Palos Verdes 

sand but is rare in that unit. The shell on which H. 

antiquatus is based is from Barbados. 18 In general 

features and sculpture California shells closely resemble 

West Indian shells. The outline, height, and position 

of the apex are variable. Lots from California include 

flatter specimens than lots from the West Indies. The 

44 specimens from Neah Bay, Washington, constituting 

the type material of the variety cranioides, are divided 

into four lots showing complete gradation from the 

high marginal apex of the typical form to the flat 

subcentral apex of cranioides. The type lot of H. 

tumens consists of four specimens from Monterey. ' 

CKEPIDTJLIDAE 

The large Crepidula collected only from the Timms 

Point silt is identified as a small variety of Crepidula 

princeps (p. 32, figs. 5, 6). It has been recorded as 

C. princeps and C. grandis. The type of C. princeps is 

» Willett, George, op, cit. (San Diego Soc. Nat. History Trans., vol. 8, No. 30), 

p. 399, 1937. 

'8 Hanley, Sylvanus, Ipsa Linnaei Conchylia, p. 422. London, 1855. 

an incomplete large shell from the lower Pleistocene 

Santa Barbara formation at Santa Barbara and is in 

the collection of the National Museum (1839; length 

86 millimeters, width 64 millimeters, height 39 milli 

meters). An exceptionally fine and characteristically 

large specimen (length 110 millimeters, width 56 milli 

meters, height 50 millimeters) from the type region 

was figured by Arnold. 19 In this species the edge of 

the deck has a wide asymmetric indentation on the 

adapical side of a median plane. A furrow on the 

hidden face of the deck, along which the deck is rela 

tively thin, corresponds to the apex of the indentation; 

elsewhere the deck is thick. The almost complete 

Timms Point specimen shown on plate 32, figures 5, 6, 

is as large as any examined from the Sari Pedro district. 

It has a length of 55 millimeters, a width of 40.5 milli 

meters, and a height of 23 millimeters. The edge of 

the deck is broken or inaccessible on available speci 

mens. The deck is as thick as on Pleistocene specimens 

of C. princeps of the same size from Rincon Point, on 

the coast between Santa Barbara and Ventura, but 

the furrow on the inner face is less conspicuous. The 

identification of the Timms Point form as a small 

variety of C. princeps is based principally on the 

thickness of the deck. The large typical form of 

C. princeps is not in any available material from the 

San Pedro district. It occurs in the lower Pleistocene 

at Santa Barbara and Rincon Point, is widespread in 

the Pliocene particularly in the upper Pliocene and 

is recorded from the Miocene. Arnold recorded 

C. "grandis 1 ' only from the Palos Verdes sand of 

Deadman Island, but it has not been found elsewhere 

in the Palos Verdes sand despite extensive collecting. 

The dimensions cited by Arnold (length 80 millimeters), 

based presumably on one of his specimens from the 

San Pedro district, represent a shell considerably 

larger than the Timms Point specimens collected. 

Crepidula grandis is a moderately large Recent Alaskan 

and Siberian species, comparable in size to the Timms 

Point form. The largest specimen in the collection 

of the National Museum has a length of 55 millimeters, 

a width ot 42 millimeters, and a height of 17 milli 

meters. The deck is thin and has a very shallow, wide 

indentation on the adapical side. It is doubtful 

whether C. grandis and C. princeps are closely related. 

Five other species of Crepidula are represented in 

the Pleistocene strata. C. onyx is rare in the Lomita 

marl and San Pedro sand, fairly common in terrace 

deposits, and abundant in the Palos Verdes sand. 

The deck, which is not far below the aperture, has a 

narrow indentation on the abapical side and a wider 

indentation on the adapical side. The rich brown 

color of the interior below the deck is conspicuous in 

the fossils, as noted by Arnold. C. adunca is common 

in the Lomita marl, San Pedra sand, and terrace de 

posits, is abundant on the Palos Verdes sand, and is 

recorded from the Timms Point silt. 20 It is small, 

deeply cup-shaped, and the cavity above the deck ex 

tends into the apex. The deck is far below the level 

of the aperture, and its edge is simply curved. Speci 

mens from a San Pedro sand collection (locality 30) 

and from a Palos Verdes collection (locality 108) are 

identified as C. excavata. In this species the apex is 

at the level of the aperture, and the edge of the deck is 

almost straight, being slightly arched at the ends. 

" Arnold, Ralph, Geology and oil resources of the Summerland district, Santa 

Barbara County, Calif.: U. S. Geol. Survey Bull. 321, pi 13, figs, la-lc, 1921. 

20 Clark, Alex, op. cit. (San Diego Soc. Nat. History Trans., vol. 7, no. 4), table op. 

p. 30,1931.

According to Arnold's description of the edge of the 

dock, his C. rugosa is the species identified in this re 

port as C. excavaty. The Pleistocene form from the 

Ventura Basin described as C. saugusensis should be com 

pared with C. excavata. C. aculeata is recognized in a 

few terrace collections and is recorded from the San 

Pedro sand. This species has spiny ribs, and the deck 

has an indentation on the abapical side and a double 

indentation on the adapical side. Specimens of this 

species from the Pacific coast from Panama to southern 

California closely resemble West Indian shells. The 

flat variable C. nummaria occurs in all the units but 

is rare, in the Timms Point silt and is not common in 

the Palos Verdes sand. Shells are thin or thick, and 

some exceptionally thick shells are lamellar. Arcuate 

shells of this species that lived in the aperture of 

gastropods have a striking outline. The deck has a 

narrow indentation, at the abapical edge 

Crepipatella,'21 characterized by a peculiar deck, is 

given generic rank. The deck is deeply concave and 

has an exceptionally deep indentation at the abapical 

edge and a minor indentation .near the middle that 

corresponds to a swelling on the outer face. Crepi- 

patella lingulata is recognized in all the Pleistocene 

units except the Timms Point silt and is recorded 

from that unit. 22 It is most widespread in terrace 

deposits and is very abundant at locality 105. The 

apex is Calyptraea-likQ, and the shell is smooth or 

roughened either irregularly or to form crude radial 

ribs. The indentation at the abapical edge of the deck 

is narrow and deeper than in the type of the genus. 

Crcpijmtdla charybdis (pi. 29, fig. 24; pi. 32, figs. 

7, 8), for which the generic name Verticumbo 23 has been 

proposed, is fairly common in the Lomita marl and 

Timms Point silt and is represented by a specimen from 

the San Pcd.ro sand (locality 30). It resembles C. 

lingulata, but the Cahftrtraea-likG apex is larger, and 

the remainder of the shell is sculptured with weak to 

strong, irregular, and irregularly swollen radial ribs. 

The deck is perfectly preserved on only one small 

Timms Point specimen (pi. 32, fig. 8). The abapical 

indentation is not so narrow nor so deep as in Crepi- 

patella lingulata, and' the median indentation is very 

shallow. The adapical edge is strongly bent toward the 

aperture, a feature observable even 011 specimens that 

have an imperfect deck. It is probably most closely 

related to the unfigured "Crepidula" orbiculata 24 (type 

locality, Victoria, Vancouver Island). That species 

lacks, however, the sculpture, and the adapical edge of 

the deck is not strongly upturned. Crepipate.Ua 

charybdis is living in moderately deep water off the coast 

of southern California. The upturned deck edge is 

preserved on a specimen (224683) in the collection of 

the National Museum, which was dredged off Santa 

Cruz Island at a depth of 155 fathoms. On two small 

specimens (209067)' dredged in 55 to 67 fathoms off 

Point Loma the upturning is not so strong. These 

three Recent shells have a large apex and deck indenta 

tions like the fossils, and the sculpture is moderately 

strong. This species has recently been dredged by 

" Lesson, K. Py Voyage do la Coguille, Zoologie, vol. 2 pt. i, p. 389.1830 (1831, 

fldo Shorborn). Subsequently designated type (Gray. J. E.. Zool. Soc. London 

Proc., 1847, p. 57). Caluptraea adolphel Lesson (= Creptdula 'dilatata Lamarck, fide 

Dall), llccent. Peru. C. dilatata was described from an unknown locality. As 

figured by Dolossort, it is reasonably similar to Peruvian shells. Neither Lesson's 

nor Dolcssort's illustrations show the minor indentation near the middle of the deck. 

" Clark, Alox, op. cit. (San Diego Soc. Natural History Trans., vol. 7, No. 4), 

table op. p. 30,1931. 

" Berry, S. S., New Mollusca from the Pleistocene of San Pcdro, Calif., I: Bull. 

Am. Paleontology, vol. 26, No. 94a, p. 8, pi. 1, figs. 6-10,1940. 

«< Dall, W. H.. Descriptions of now species of Mollusca from the North Pacific 

Ocoan in the collection of the United States National Museum: U. S. Nat. Mus. 

Proc., vol. 56, p. 361,1919. 


Messrs. Tom and John Q. Burch .at a depth of 50 

fathoms off Redondo Beach, Calif. 

CALYPTRAEIDAE 

A rather flat large-tipped Calyptraea found in the 

Lomita marl and' San Pedro sand is identified as C. 

fastigiata (type locality, Puget Sound.). It is presum 

ably the species recorded from the Timms Point silt 25 

and Palos Verdes sand as C. mamillaris. C. mamillaris 

is a southern species that has a thicker shell, and the 

upper part of unbleached specimens is light brown. 

The genus Crucibulum is represented by C. spinosum. 

It is common.in the Palos Verdes sand, present in two 

terrace collections, and is recorded from the San Pedro 

sand. 

NATICIDAE 

The. genus Cryptonatica is common in the Lomita 

marl, Timms Point silt, and locally in the San Pedro 

sand. It is represented but rare in the.Palos Verdes 

sand at two localities (108, 120) and was not found in. 

terrace deposits^ The collection from the Lomita marl 

at locality 67 includes an operculum. Identification of 

species is uncertain, owing to uncertainty concerning . 

the Recent forms. The fossils represent presumably 

one species having a spire of variable height. . Some 

specimens are bleached, but numerous others show a 

brownish color. The Timms Point Cryptonatica has 

been identified recently by Willett 26 as C. russa on the 

grounds that that species has a heavier callus pad and 

darker color than C. clausa, a name that has been used 

for Pleistocene fossils from the San Pedro district. The 

largest fossil at hand is from the San Pedro sand at 

Deadman Island (locality 30) and has a length of 23.7 

millimeters and a width of 24 millimeters. The others 

are considerably smaller or much smaller, with the 

exception of one specimen from the Palos Verdes sand 

at Arnold's Crawfish George's locality (locality 108). 

The best Lomita marl specimens are from the central 

shaft of the Whites Point tunnel (locality 57). Many 

specimens from other Lomita marl localities and from 

the Timms Point silt are partly exfoliated. Other small 

exfoliated naticids on which the callus is removed are 

indeterminable generically. 

Neverita is the most abundant naticid genus. It is 

locally common in the Lomita marl, apparently rare 

in the Timm.s Point silt, rare in terrace deposits, 

abundant in the San Pedro sand, and very abundant 

in the Palos Verdes sand. Two forms are recognized 

N. reclusiana alta, which occurs in all the Pleistocene, 

units, and N. reclusiana imperforata, found only in the 

Palos Verdes sand. As pointed out by Pilsbry, 27 

Recent specimens of N. reclusiana alta have a brown 

callus and generally have a tonguelike extension of 

callus above the groove. The brown coloration of the 

callus, lighter than on Recent shells, is preserved on a 

few fossils from the Lomita marl, San Pedro sand, and 

Palos Verdes sand. The tonguelike extension of callus 

appears to be the most satisfactory character to 

differentiate fossil specimens of the variety alta from 

N. reclusiana proper. Despite the name, fossil and 

Recent shells have a spire of variable height. Pilsbry 

designated a specimen from the Palos Verdes sand at 

locality 112 as a neotype of N. reclusiana alia, a name 

first published by Arnold for specimens from the Palos 

« Clark, Alex., op. cit. ... 

" Willett, George, op. cit. (Southern California Acad. Sci. Bull., vol. 36), p. 63,1937 

27 Pilsbry, H. A., Neverita reclusiana (Desh.) and its allies: Nautilus, vol 42 DD 

109-113, pi. 6,1929. ' pp


Verdes sand. The only large Lomita specimens are 

from Hilltop quarry (locality 53a). The few Timms 

Point specimens are small, poorly preserved, and 

determinable only generically; in fact, most of the 

Timms Point naticids are indeterminable generically. 

Aside from a small shell collected at locality 86, the 

terrace Neveritae are worn or broken, or both (locali 

ties 93, 106). Some from locality 93 show the tongue- 

like extension of the callus; the other terrace specimens 

are not determinable beyond the genus. Only a few 

specimens of N, reclusiana proper are in the collection 

of the National Museum. They represent a range 

from Santa Barbara to Catalina. N. reclusiana alta 

is represented by many lots and is a southern form, the 

specimens being from localities ranging from San Diego 

to Lower California and the Gulf of California. It is 

recorded by Pilsbry from Newport Bay, between San 

Pedro and San Diego. 

Neverita reclusiana imperforata is characterized by a 

low spire, generally by a somewhat cylindrical outline, 

and by a thick callus that fills 'the umbilicus completely 

or almost completely. The fossils assigned to this 

form are readily distinguishable, with the exception 

of some small shells. This form is widespread and 

locally abundant in the Palos Verdes sand and is asso 

ciated with N. reclusiana alta at five localities. Arnold's 

figured N. reclusiana from the Palos Verdes' sand and 

the Recent specimen figured by Grant and Gale as the 

variety N. reclusiana callosa represent N. reclusiana 

imperforata. Recent shells in the National Museum 

represent forms that range from Crescent City to San 

Diego; that is, the variety imperforata appears to range 

farther north than N. reclusiana proper or the variety 

alta. Observations on the habitats and distribution 

of the three forms of Neverita, which, as emphasized by 

Pilsbry, are needed to determine their status, have not 

been recorded. Among the fossils, N. reclusiana im 

perforata is more distinct than N. reclusiana alta. 

The genus Lunatia,, which has a more northern range 

than Neverita, is represented by Lunatia lewisii in the 

three lower Pleistocene units and in the Palos Verdes 

sand. It is much less abundant, however, than 

Neverita, unless most of the small and medium-sized 

indeterminable naticids in the Timms Point silt repre 

sent Lunatia. L. lewisii reaches a much larger size 

than the forms of Neverita, and large shells are more 

strongly shouldered. The umbilical callus is grooved, 

as in the forms of Neverita, but covers a smaller area. 

Large or moderately large shells were collected from 

the Lomita marl at Hilltop quarry (localities 53, 53a), 

from the San Pedro sand at localities 30 and 48, and 

from the Palos Verdes sand at localities 112 and 121. 

VELUT1NIDAE 

A small imperfect shell from the Lomita marl at 

locality 54g appears to represent the Recent Pacific 

coast species considered conspecific with the north 

Atlantic Velutina laevigata. That species has been 

recorded recently from the Timms Point silt. 28 At the 

present time it is not known to range south of Monterey. 

Lamellaria stearnsii, a representative of the family 

JLamellariidae, is recorded from the San Pedro sand 

at Deadman Island. 29 

" Willett, George, op. cit. (Southern California Acad. Sci. Bull., vol. 36), p. 63,1937. 

"Arnold, Ralph, op. cit. (California Acad. Sci. Mem., vol. 3), p. 317, 1903. 

CYPRAEIDAE 

Cypfaea spadicea, the only species of the genus living 

on the California coast, occurs in the Lomita marl at 

Hilltop quarry and in terrace deposits and is repre 

sented in the Palos Verdes sand by a doubtful fragment. 

The best specimens are from the fourth terrace at 

locality 82. 

One specimen of Trivia californica was found in 

deposits on the fourth terrace at locality 84. The 

larger and more deeply grooved T. solandri occurs in 

deposits on the second terrace at locality 105, and a 

fragment from the Palos Verdes sand represents 

probably that species. Arnold found T. californica in 

the Palos Verdes sand and T. solandri in the San Pedro 

sand. T. ritteri, which lacks the dorsal groove, has 

been recorded recently from the Times Point silt. 30 

Erato vitellina (pi. 30, fig. 3), heretofore not recorded 

from the Plesitocene of the San Pedro district, is repre 

sented by a specimen from the Lomita marl at locality 

57. Owing to the absence of most of the denticles 

usually present on the inner lip, this specimen was 

mistaken for a marginellid until its affinities were 

pointed out by Mackenzie Gordon, Jr. Two fragments 

from deposits on the second terrace at locality 105 are 

presumably E. columbella, which Arnold found to be 

rare in the Palos Verdes sand. 

CYMATIIDAE 

Fusitriton oregonensis occurs in the Lomita marl at 

Hilltop quarry and nearby, in the Timms Point silt 

(pi. 32, fig. 9), is recorded from the San Pedro sand, and 

is represented in the Palos Verdes sand by a small 

broken specimen in the collection from Arnold's Craw 

fish George's locality (locality 108). It is rare except 

in the Timms Point silt. 'In that unit it is represented 

in three collections from Timms Point, in a collection 

from San Pedro (locality. 40), and in a collection from 

the north border of the western part of the hills (locality 

66). The fossils have the strong varices characteristic 

of Recent shells. The figured specimen is of medium 

size, but broken shells from the Timms Point silt and 

Lomita marl are larger, almost as large as shells from 

Puget Sound. The southernmost specimen in the col 

lection of the National Museum was dredged at a depth 

of 1,081 to 1,100 fathoms off San Nicolas Island. Mr. 

George Willett, of the Los Angeles Museum, dredged a 

small specimen at a depth of 80 fathoms off Catalina. 

BUKSIDAE 

Bursa californica was found in the Lomita marl (pi. 

29, fig. 25) and Palos Verdes sand and is represented by 

a doubtful fragment hi a collection from the third ter 

race at locality 93. It is abundant in the algal bed of 

the Lomita at Hilltop quarry, where it is represented 

by well-preserved specimens of different sizes. The 

only other Lomita marl material consists of fragments 

from localities 54g and 6 1 . The Palos Verdes specimens 

consist of a doubtful fragment from locality 112 and a 

young shell from locality 126. 

EPITONIIDAE, PYRAMIDELLIDAE, AND MELANELLIDAE 

The numerous epitonids, pyramidellids, and melanel- 

lids have not been identified. Thirteen species of 

epitonids, two of which are said to be unknown in the 

living state, are recorded from the Pleistocene strata of 

the San Pedro district. Forty-four species of pyra- 

» Willett, George, op. cit. (Southern Calif. Acad. fci. Bull., vol. 36), p. 62,1937.

midellids are on record, half of which are not reported 

to be living. The large number of species and the 

large number of forms thought to be extinct, as com 

pared with other families, strongly suggest that the 

Pleistocene representatives of this family are over- 

named. Eleven species of melanellids are recorded, 

four of which are not reported to be living. 

FUS1NIDAE 

Three species of the genus Barbarofusus are recog 

nized, and a third species generally referred to Bar 

barofusus or "Fusinus" is assigned to Harfordia. Bar- 

barojusus barbarensis, as identified by Arnold, is large 

and slender and has a relatively long, narrow canal. 

On large specimens the axial ribs fade out on the penul 

timate whorl. This species is identified in the Lomita 

marl o,nd San Pedro sand and is recorded from Timms 

Point silt and Palos Verdes sand. A well-preserved 

specimen from the San Pedro sand of Deadmaii Island 

(locality 30; pi. 34, fig. 9) is the largest of the fossils. 

None of the fossils are as large as two exceptionally 

large shells (length about 130 millimeters) mentioned 

by Dall, 31 dredged in 30 fathoms off Newport Bay. B. 

barbarensis was based on fossil material from Santa 

Barbara. According to a communication from Dr. L. 

G. Hertlein, of the California Academy of Sciences, the 

type material of the species of "Fusus" described by 

Trask in 1855 is no longer in existence. A specimen 

from the Santa Barbara formation at Santa Barbara 

should be designated the neotype of B. barbarensis. 

Inasmuch as no specimens from Santa Barbara are at 

hand, the usage of the name is based on Arnold's iden 

tification of San Pedro specimens. 

Barbarofusus arnoldi is stouter than B. barbarensis 

and has strongly shouldered whorls, producing a tur 

reted spire, and a shorter and wider canal. It is recog 

nized in the San Pedro sand (pi. 34, figs. 10, 11) and is 

represented by a small specimen from the Palos Verdes 

sand, at Arnold's Crawfish George's locality (locality 

108). The spirals of well-preserved fossils are colored 

brown. This species was based on fossil material from 

San Pedro. The specimen from the San Pedro sand at 

Deadman Island shown on plate 34, figure 10, is desig 

nated the neotype. Both B. barbarensis and B. arnoldi 

have a stout nucleus that has a pointed apex, and near 

the end of the nucleus a few axial ribs merge into the 

postnuclear sculpture. The upper edge of the first 

uucleur whorl appears to be more strongly angulated in 

B. arnoldi than in B. barbarensis. 

The Barbarofusus from the Timms Point silt is 

relatively small and has brown spirals like B. arnoldi, 

but the spire is not turreted. This form is identified 

provisionally as Barbarofusus cf. B. arnoldi (pi. 32, 

iig. 10). 

^Harfordia monksae is widespread in the Lomita marl 

(pi. 29, fig. 26) and occurs in terrace deposits and the 

Palos Verdes sand. It is smaller than'the species of 

Barbarofusus and has a short stout pillar and corres 

pondingly short wide canal. The primary spirals are 

heavy and colored dark brown on well-preserved fossils. 

The only satisfactorily preserved terrace specimens are 

from tho second terrace at. locality 98. This species 

also was based on fossil material from San Pedro. 

The best specimens in the collections gathered during 

the field work for this report are from the Lomita marl. 

Inasmuch as the Lomita marl was presumably not 

a' Dnll, W. H., Notes on tho west American species of Fuainua: Nautilus, vol. 29, 

p. 55, 1015. 


accessible to Trask, it would be inappropriate to 

designate a neotype from that unit. The larger of 

two fossils (124757; length 43.7 millimeters, width 18.5 

millimeters) from San Pedro, collected by Miss Monks, 

in the collection of Recent California mollusks in the 

National Museum is designated the neotype. These 

two fossils are labeled "Pliocene," implying the Timms 

Point silt, but the matrix consists of sand, and they 

are probably from the Palos Verdes sand, the only unit 

in which Arnold found this species. Harfordia monksae 

has the short relatively wide canal and heavy spirals 

of H. harfordi, the type of that genus. The nucleus of 

PL harfordi is not known; the nucleus of H. monksae is' 

like that of Barbarofusus arnoldi. 

"Fusinus" luteopictus appears to be represented in 

terrace deposits by minute young shells from localities 

75 and 86 and by an imperfect, presumably adult, shell 

from locality 77. The nucleus is turreted and near the 

end is sculptured with a few axial riblets. Arnold 

found this small species in the San Pedro sand and Palos 

Verdes sand. It appears to be related to Harfordia. 

M1TRIDAE 

' The genus Mitra is represented by two species, both 

of which represent the subgenus Atrimitra. Mitra 

idae was found in the Lomita marl and in terrace 

deposits and is recorded from the Timms Point silt, 

the San Pedro sand, and the Palos Verdes sand. M. 

fultoni, a southern species not recorded heretofore from 

the San Pedro district but recorded recently nearby, 32 

was collected from deposits on the second terrace at 

locality 105. 

"NASSIDAE" 

Gastropods of the family "Nassidae" are perhaps 

the most abundant of the carnivorous gastropods. 

Seven species and two additional varieties are recog 

nized. They fall into four genera or subgenera, the 

distinguishing characters of which are as follows: 

Outer lip varicose: 

Parietal callus thick.____________________ "Nassa" tegula 

Parietal callus not thick_________________"N." insculpta 

Outer lip not varicose: 

Inner lip lirate______ "N." fossata, "N." fossata coilotera, 

"N." delosi, "N." cerritensis, "N." perpj-nguis 

Inner lip swollen above basal fold but not lirate. .__ "N." 

mendica, "N." mendica cooperi 

Inasmuch as the generic affinities of the species have 

not been determined, they are referred to "Nassa." 

It may be pointed out, however, that the first group 

represents Nassarius proper and that Schizopyga is 

available for the third group. 

"Nassa" tegula occurs in the Palos Verdes sand and 

is recorded from the San Pedro sand. "N." insculpta 

was foimd in^ the Lomita marl (pi. 29, fig. 27), and 

Arnold found one specimen in the Palos Verdes sand. 

"Nassa" fossata, the largest of the nassids, is com 

mon in the San Pedro sand and the Palos Verdes sand 

and is recorded from the Timms Point silt and deposits 

on the second terrace. Specimens from Arnold's 

Crawfish George's locality are exceptionally large and 

slender and have an exceptionally wide concave area 

between the shoulder and the suture, characters 

mentioned by Arnold 33 for specimens from that 

locality. The new varietal name "N." fossata coilotera 

(pi. 35, figs. 10, 11) is proposed for this form. The 

"a Willett, George, op. cit. (San Diego Soc. Nat. History Trans., vol. 8, No. 30) 

p. 395, 1937. 

« Arnold, Ralph, op. cit. (California Acad. Sci. Mem., vol. 3), p. 233,1903.


largest specimen (length, not quite complete, 50.7 

millimeters) is larger than the type. Immature shells 

are indistinguishable from "N." fossata proper, except 

that they are slightly more slender. This variety is 

not known to be living. The most similar form in the 

collection of the National Museum is a stouter shell 

from Oregon (252997). 

The recent species that has been designated "N." 

californiana is presumably not that species and evidently 

needs a new name. The status of "N." californiana, 

based on fossil material that is lost, is uncertain, how 

ever, until a neotype is designated. It is probably the 

Pliocene species that was later named "N." moraniana. 

That species is stouter and more strongly noded than 

the Recent "californiana," and has more closely spaced 

ribs and more numerous stronger lirations on the 

inner lip. 

"Nassa" moraniana and the Recent "californiana" 

are not represented in the collections from the Pleisto 

cene strata of the San Pedro district. Despite records 

to the contrary, it is doubtful whether the Recent form 

occurs there. The new name "Nassa" delosi (pi. 35, 

figs. 12-15) is proposed for Arnold's figured "califor 

niana" from the Palos Verdes sand. That form was 

found only in the Palos Verdes sand and is not known 

to be living. It has more numerous and stronger lira 

tions on the inner lip than the Recent "californiana," 

stronger axials, and the axials are farther apart on the 

later whorls. It is perhaps to be regarded as a form of 

the Recent "californiana"; very young shells are in 

distinguishable. It is also similar to "N." cerritensis 

but is more-slender, and the axials are not so strong on 

the later whorls. Three specimens of "N." delosi in 

the National Muesum collection of Recent California 

mollusks are labeled "Nassa delosi Qldroyd and Herold/ ' 

evidently a manuscript name. It is appropriate to 

validate this name in honor of Delos Arnold, for many 

years an enthusiastic collector of San Pedro Pleistocene 

fossils. 

"Nassa" cerritensis (pi. 35, figs. 16-19) is slender and 

has very strong axials that are far apart on the later 

whorls; it has a few lirations on the base of the inner 

lip. The type is from Los Cerritos, or Signal Hill, 

near Long Beach. Arnold correlated the strata at 

that locality with the Palos Verdes sand, a correlation 

that is justified. In the San Pedro district "N." 

cerritensis was found only in the Palos Verdes sand by 

Arnold and also during the field work on which the 

present report is based. According to numerous speci 

mens in the National Museum, a small race of "N." 

cerritensis or a closely related species is living along the 

Lower California coast at Point Abreojos and Ballenas 

Bay and in the Gulf of California at Guaymas. 

"Nassa" perpinguis is smaller than the Recent 

"californiana" and has more closely spaced axials and 

spirals. It is common in the Lomita marl and Timms 

Point silt, is abundant in the San Pedro sand and Palos 

Verdes sand, and is recorded from the second terrace. 

"Nassa" mendica occurs in the three lower Pleisto 

cene units and in the Palos Verdes sand and is recorded 

from the second terrace. It is most abundant in the 

San Pedro sand. The strength and spacing of the ribs 

is variable. Grant and Gale cited 1851 as the date of 

publication of this name. In that event it would be 

replaced by "N." woodwardi, published in. 1850. The 

signature of the part of volume three of the Proceed 

ings of the Boston Society of Natural History contain 

ing the description of "N." mendica is dated January> 

1850. The date is, therefore, doubtless earlier than 

the date of publication of "N." woodwardi. The 

characters of "N". mendica indisputabilis have appar 

ently not been defined. Two fossils under that name 

from the San Pedro district, received from Mrs. Old- 

royd, which were evidently from the San Pedro sand, 

are in the collection of the National Museum. They 

represent a large slender form of "N." mendica that 

has closely spaced axials (length 24.5 millimeters, 

width 10.5 millimeters). Carpenter 34 thought that 

the species described'as Nassa interstriata (or intastriata), 

based on Pleistocene material from San Pedro, was 

"N." mendica. The type material is lost. 

"Nassa" . mendica cooperi is the most abundant 

"Nassa," the only one found in all the Pleistocene units 

and the only one collected from terrace deposits. It is 

particularly abundant in the San Pedro sand (pi. 34, 

fig. 12). It is characterized by heavy widely spaced 

axials but appears to intergrade with "N." mendica 

proper. Its widespread occurrence in terrace deposits 

suggests that its depth range extends into shallower 

water than that of the other forms of "Nassa." 

"Nassa" versicolor hooveri is not represented in the 

collections at hand. The type, which according to 

Arnold was placed in the National Museum, appears to 

be missing. This form is apparently not closely similar 

to "N." versicolor, which has heavy ribs. 

NEPTTJNEIDAE 

Neptunea tabulata, the only species of the genus in the 

Pleistocene strata, is common and widespread in the 

Timms Point silt (pi. 32, fig. 11) and is rare in the 

Lomita marl and San Pedro sand. An incomplete large 

specimen was collected from the Lomita marl at Hilltop 

quarry (locality 53a). The only other Lomita material 

consists of doubtful fragments from localities 54e and 71. 

The material from the San Pedro sand consists of a 

broken large specimen from Deadman Island and 

fragments from localities 58a and 65. None of the 

fossils have the strong axial frills bordering the sutural 

depression of many Recent shells, and none have a 

sutural depression so deep as on most Recent shells. 

Exilioidea rectirostris, also the only species of the 

genus in the Pleistocene strata, occurs in the Timms 

Point silt (pi. 32, fig. 12) and is represented in the Palos 

Verdes sand by a worn broken specimen from Arnold's 

Crawfish George's locality (locality 108). Arnold 

recorded the same distribution for this species, with the 

exception.that he found it also in the San Pedro sand at 

Deadman Island. The figured Timms Point specimen 

and others.are more slender than Recent specimens of 

the same size; the strength of the spiral sculpture is 

variable. The type is a partly corroded shell from 

Puget Sound. The southernmost specimen in the col 

lection of the National Museum is from a depth of 233 

fathoms in the Santa Barbara Channel. Mr. George 

Willett, of the Los Angeles Museum, has in his collection 

a specimen that he dredged off Catalina at a depth of 

80 fathoms. 

Kelletia kelletii represents the monotypic genus 

Kelletia. It was found in the Lomita marl and is re 

corded from the Palos Verdes sand. It is relatively 

abundant in the algal bed at Hilltop quarry (locality 

53a), and some of the specimens collected there are 

fully as large as the largest Recent shells. Calicantharus 

s< Carpenter, P. P., A supplementary report on the present state of our knowledge 

with regard to the Mollusca of the west coast of North America: British Assoc. Adv. 

Sci. Kept. 1863, p. 500,1864.

fortis is widespread and locally abundant in the Loraita 

marl (pi. 29, figs. 28, 29), is represented in the San Pedro 

sand at Dcadman Island by a partly broken and partly 

worn, specimen probably the shelter of a hermit crab 

and is recorded from the Timms Point silt and Palos 

Vcrdes sand. The type material of C.jortis, apparently 

lost, was collected from Pleistocene strata near Santa 

Barbara. Specimens from the Palos Verdes Hills have 

a :m ore rounded shoulder and a flat or less concave area 

between, the shoulder and the suture than Pleistocene 

specimens from Rincon Point, a locality on the coast 12 

miles southeast of Santa Barbara; also Palos Verdes 

Hills specimens are not as large as the largest from 

Kiucon Point. As may be seen from figures 28 and 29 

on plate 29, the degree of differentiation of primary and 

secondary spirals and the stage at which the axial ribs 

fade out are variable. This species is the type and last 

known survivor of the recently proposed Calicantharus.^ 

The strong spirals, separated by deep narrow inter 

spaces, arc as characteristic as any feature of the genus, 

and permit identification of fragments. The genus is 

closely related to Siphonalia, Kelletia, and the Recent 

Pacific coast genus currently called Searlesia, but the 

relationship with Cantharus is probably remote. Cali 

cantharus is represented by several Pliocene species 

Siphonalia gilberti from the upper part of the Pico forma 

tion of Los Angeles (closely related to the Rincon Point 

form of Calicantharus fortis and perhaps to be regarded 

as a strongly ribbed form of that species), presumably 

Chrysodomus diegoensis from the San Diego formation 

(the/ type and only specimen of which is no longer ex 

tant), Thais kettlemanensis 30 from, the Etchegoin forma 

tion, Fusus (Iluccinofusus) portolaensis from the Etche 

goin, and Naptunea hume?'osa and variety N. humerosa 

angulata from the Pliocene strata at Elsrnere Canyon. 

The genus is represented in the upper Miocene by Chry 

sodomus pabloensis. It is doubtful whether the Eocene 

species assigned to Calicantharus are congeneric with 

Calicantharus fortis. The Recent Mexican Cantharus 

elegans ("insignis") has been cited as a close relative of 

Calicantharus fortis. Inasmuch as it has a different 

type of sculpture, weaker and more widely spaced lira- 

tions on the interior of the outer lip, fewer and weaker 

lirations on the inner lip, and a wider siphonal fasciole, 

the relationship is considered remote. 

Macron aethiops kcllettii is rare in the San Pedro sand 

at localities 49 and 49a; Arnold found one specimen in 

the Palos Verdos sand. An incomplete specimen from 

the Lomita marl at Hilltop quarry (locality 53a) has 

strong spiral sculpture on the spire and, therefore, is 

assigned to M. aethiops proper, which has not been 

recorded from the San Pedro district. The smaller 

species M. lividus occurs in the Palos Verdes sand and 

in deposits on the sixth and fourth terraces. 

MtmiCIDAE 

Muricid gastropods are common in the Pleistocene 

strata with the exception of the Timms Point silt, in 

which they are rare and are represented only by the 

genus Tritonalia. According to Adanson's illustration 

of the type of Jaton, it lacks a tooth near the base of the 

outer lip. That name is used for "Murex" festivus and 

its allies, as was done by Grant and Gale. Jaton 

festivus occurs in the Polos Verdes sand, is represented 

by worn and broken specimens in deposits on the second 

« Clark, B. L., Fauna from the Markley formation (upper Eocene) on Pleasant 

Crock, Calif.: Geol. Soc. America Bull., vol. 49. p. 712.1938. 

«« Stowart, Ralph, in Woodring, W. P., Stewart, Ralph, and Richards. R. W.. op. 

cit. (U. S. Qeol. Survey Prof. Paper 195), p. 87, pi. 31, figs. 1, 7,1940 [19411, ("Siphon, 

alia"). 692787 i5 6 


terrace, and is recorded from the San Pedro sand 

Jaton gemma, not previously reported from the San 

Pedro district, was found in the algal bed of the Lomita 

marl at Hilltop quarry (pi. 30, fig. 1) and is represented 

by poorly preserved shells from deposits on the fourth 

and third terraces. The figured specimen from the 

Lomita marl shows the characteristic brown spirals. 

Characters that differentiate the Pliocene J. eldridgei 

from J. gemma are not known; the absence of lamellae 

on the type of J. eldridgei is probably due to poor preser 

vation. J. santarosanus has a longer canal than J. 

gemma and lacks brown spirals. Heretofore not 

recorded from the San Pedro district, J. santarosanus 

appears to be represented by an incomplete specimen 

from deposits on the second terrace at locality 105. 

Both J. gemma and J. santarosanus have been found in 

late Pleistocene strata near Playa del Rey. 37 

The genus Pterorytis 38 (emended to the etymologicaUy 

more correct Pterorhytis by some writers), "Purpura" 

of current California literature, is similar to Jaton but 

has a spine near the base of the outer lip. Pterorytis 

nuttalli was found in deposits on the third terrace and 

in the Palos Verdes sand and is probably represented by 

a fragment from the Lomita marl. 

Tritonalia is the most abundant of the muricids. 

T. poulsoni, the largest of the Pleistocene species, occurs 

in the Palos Verdes sand and is recorded from the San 

Pedro sand. T. sguamulifera 39 (pi. 34, fig. 13) was found 

only in the San Pedro sand. As pointed out by Willett, 40 

Arnold's figured "Ocinebra" barbarensis, also from the 

San Pedro, is T. sguamulifera. 

Tritonalia interfossa, which has a turreted spire, 

coarse reticulate sculpture, and somewhat lamellar 

axials, is the only species of the genus recognized in all 

the Pleistocene units. If T. barbarensis is represented 

in the collections, it has not been distinguished from 

small specimens of T. interfossa that have lamellar ribs 

and spines on the lamellae at the shoulder. T. keepi, 

the type of which is a well-preserved shell from the 

Palps Verdes sand, is evidently a large strongly lamellar 

variety of T. interfossa. It is represented in the San 

Pedro sand at locality 58 by an imperfect specimen, 

but it is not known to be living. Small nonlarnellar 

shells from the San Pedro sand at other localities are 

identified as Tritonalia cf. T. interfossa keepi. 

A species from the Lomita marl, the fourth and 

second terraces, and the Palos Verdes sand is identi 

fied as Tritonalia foveolata. Should that name prove 

to be unsuitable, T.fusconotata (type locality Monterey) 

is available. Arnold's T. lurida aspera is the form 

identified as T. foveolata. The northern T. lurida 

(+ aspera) is more slender and has more ribs. A 

form of T. circumtexta from the fifth, fourth, and second 

terraces is identified as T. circumtexta aurantia. The 

fossils are smaller and more slender than T. circumtexta 

proper, and some show the orange color of T. circum 

texta aurantia. The fossils are .identical with the 

variety T. circumtexta citrica, which appears to be a 

synonym of T. circumtexta aurantia. The type of 

Arnold's Ocinebra lurida var. cerritensis, from the 

Palos Verdes sand at Crawfish George's locality, is 

considered a worn T. circumtexta proper. Despite its 

37 Willett, Qeorga, op, cit. (San Diego Soc. Nat. History, Trans., vol. 8, No. 30), p. 

397, 1937. 

M Conrad, T. A., Catalogue of the Miocene shells of the Atlantic slope: Acad. Nat, 

Sci. Philadelphia Proc., 1862, p. 560. Monotype, Murex umbrifer Conrad, Miocene. 

Virginia. 

88 Carpenter, P. P., in Oabb, W. M., Cretaceous and Tertiary fossils: California 

Qeol. Survey, Paleontology, vol. 2, p. 44,1869. 

40 Willett, George, Remarks on some west American mollusks: Nautilus, vol. 52, 

p. 10, 1938. .

76 

small size and weak ribs on the body whorl, T. gracillima. 

has a heavily varicose outer lip. Two fragments from 

the twelfth terrace are doubtfully identified as that 

species. The weakly ribbed T. -lurida munda wa,s 

found in the three lower Pleistocene units and in the 

Palos Verdes sand at Arnold's Crawfish George's 

locality. Though T. lurida, proper is recorded from the 

San Pedro district, it is doubtful whether it occurs there. 

The new name Tritonalia coryphaena is proposed for 

a large, stout, round-shouldered species from the 

Lomita marl at Hilltop quarry (pi. 30, fig. 2), repre 

sented by two specimens. It is similar to "Eupleura" 

grippi, from a depth of 15 fathoms off San Diego, but 

has stronger axials and spirals. 

The genus Eupleura is not represented in the col 

lections at hand. Arnold proposed the varietal name 

pleistocenensis for a form of Eupleura muriciformis 

from the Palos Verdes sand. The status of his variety 

E. muriciformis curta, also from the Palos Verdes sand, 

is uncertain, as the type is incomplete and badly worn. 

A species from the San Pedro sand is identified as 

Trophonopsis lasia (pi. 34, fig. 14). Though the fossils 

are small, relatively stout, and have few ribs, they 

appear to represent that variable species, which is 

generally known as "Trophon tenuisculptus."* 1 Arnold 

found "Trophon tenuisculptus" in the Timms Point silt. 

The type of "Trophon" cerritensis, from the San Pedro 

sand, is probably a worn strongly sculptured form of 

Trophonopsis lasia. 

Small species of the genus Boreotrophon are repre 

sented by numerous specimens in the Lomita marl and 

Timms Point silt, are less abundant in the San Pedro 

sand, and are rare in the Palos Verdes sand. Boreo 

trophon pedroanus, which is not known to be living, is 

found in the four units, the Palos Verdes specimens 

being from localities 108 and 121. It is a small slender 

species and has moderately strong spirals; some speci 

mens have a subangular shoulder and others a rounded 

shoulder. According to Arnold, the type of B. ped 

roanus, from the San Pedro sand, was placed in the 

National Museum, but appears to be missing. It is 

evidently a representative of the round-shouldered 

form. The type of B. praecursor, from the Timms 

Point silt, is in the National Museum; it represents 

the subangular form. B. pedroanus is smaller and more 

slender than B. orpheus; relatively stout specimens 

are, however, similar to small specimens of B. orpheus. 

A stouter species that has faint spiral sculpture, 

Arnold's "Trophon" multicostatus and "T." scalari- 

formis, is identified as Boreotrophon cf. B. pacificus. 

Smaller and more slender than the Alaskan B. pacificus. 

it is not known to be living. It was found in the 

Lomita marl and is recorded -from the Timms Point 

silt, the San Pedro sand, and the Palos Verdes sand at 

Crawfish George's locality. A larger species that has 

a strongly turreted spire, Arnold's "T." gracilis, is 

identified as B. aff. B. multicostatus. It was found in 

the Lomita marl, Timms Point silt, and Palos Verdes 

sand (localities 107 and 108) and is recorded from the 

San Pedro sand. It may be the same form as a small 

race of the Alaskan B. multicostatus, which ranges from 

Puget Sound to northern California but is not known to 

be living off the coast of southern California. 

Boreotrophon aff. B. stuarti, characterized by strong 

spirals, is represented by an incomplete small specimen 

from the Lomita marl. Arnold figured a moderately 

large specimen from the Timms Point silt and recorded 

« Willett, George, op. cit. 

this form from the San Pedro sand. The fossils are 

smaller and more slender than the Alaskan B. stuarti, a 

small race of which is represented in the collection of 

the National Museum by specimens dredged off the 

coast of southern California at depths of 59 to 202 

fathoms. A fifth species from the Timms Point silt is 

identified as B. cf. B. raymondi. It is stout stouter 

than B. avalonensis (Catalina Island, 80 fathoms) and 

the very similar or identical B. calliceratus (Point Loma, 

120-131 fathoms) has a strongly concave area ad 

joining the suture, and has stronger spirals than B. 

raymondi from the upper Pliocene of Los Angeles. It 

is not known to be living. 

THAIDIDAE 

Gastropods of the family Thaididae are not abund 

ant, with the exception of Acanthina in the Palos 

Verdes sand. A nonlamellar form of Nucella lamellom 

is represented by a worn, broken specimen from the 

Palos Verdes sand at Arnold's Crawfish George's 

locality and a doubtfully identified worn small specimen 

from the second terrace. N. emarginata is probably 

represented by small specimens from the fifth and 

second terraces and is recorded from the Palos Verdes 

sand as. "Purpura sazicola". N. biserialis occurs in 

the Palos Verdes sand at locality 142, the northwestern- 

most locality at which fossils were found in that unit. 

Heretofore unrecorded from the San Pedro district, it 

has recently been found in late Pleistocene deposits 

near Playa del Rey. 42 

Acanthina lugubris (pi. 35, fig. 1), not previously 

found in the San Pedro district, occurs in deposits on 

the fourth and second terraces. The mottled brown 

color pattern is preserved on the fossils. A. spirata is 

rare in the San Pedro sand, is represented by a few 

small shells from terrace deposits, and is abundant in 

the Palos Verdes sand. The variety A. spirata punctu- 

lata, which has a round shoulder and a reticulate brown 

color pattern preserved on fossils, is represented by 

one specimen from the Palos Verdes sand at locality 111 

and is recorded from the second terrace. 

Forreria belcheri (pi. 35, fig. 20) was found only in the 

Palos Verdes sand by Arnold and also during the field 

work for this report. It is rare, however, as only one 

specimen is in the collections at hand. 

CANCELLARIIDAE 

Cancellarid gastropods are not abundant. " Cancel- 

laria" tritonidea, a well-defined species that is not known 

to be living, occurs in the San Pedro sand and Palos 

Verdes sand (pi. 35, fig. 21) and may be represented by a 

worn fragment from the third terrace at locality 93. 

Poorly preserved specimens from the San Pedro sand 

at locality 50 are the largest collected. Arnold figured 

a large specimen from the Palos Verdes sand in his San 

Pedro memoir and in his report on the geology of the 

Coalinga district. An exceptionally large specimen in 

an old collection at the National Museum has a length 

of about 100 millimeters. This species was based on a 

loose worn shell from San Pedro that has inconspicuous 

shoulder nodes. Gabb thought, doubtless correctly, 

that it was a fossil. No closely related living species has 

been recognized, "C." cassidiformis, which ranges from 

Lower California to Panama, being smaller and stouter 

and having a higher shoulder. 

« Willett, George, op. cit. (San Diego Soc. Nat. History Trans., vol. 8, No. 30), 

p. 397, 1937.

Progabbia cooperi occurs in the Lomita marl and is 

recorded from the Palos Verdes sand. Crawfordina 

craurfordiana, found by Arnold in the Palos Verdes 

sand, is not in the collections at hand. 

A small Admete that shows a considerable range of 

variation, from slender to moderately stout, occurs in 

the Lomita marl and Timms Point silt, is recorded from 

the San Pedro sand, and is represented in the Palos 

Verdes sand by a worn broken specimen from locality 

112. It is presumably A. gracilior, which was based 

on Pleistocene material, from Santa Barbara. No 

specimens "from that locality are available. The San 

Pedro fossils are much smaller than the Alaskan A. 

couthouyi and have stronger spirals. They appear to be 

identical with the unfigured A. rhyssa (South Coronado 

Island, 55 to 155 fathoms) and to be closely related to 

the unfigured A. woodworthi (Monterey Bay. 10 to 45 

fathoms); in fact, specimens from the San Pedro sand 

were reported by Oldroyd as A. rhyssa. 

COI/UMBELLIDAE 

Mitrella carinata, M. carinata gausapata, and M. 

tuberosa are recognized in all the Pleistocene units. 

Their distribution is, however, uneven. M. carinata is 

the most widespread form and is the most abundant 

Mitrella in the San Pedro sand, terrace deposits, and 

Palos Verdes sand, but it is rare in the Timms Point 

silt. M. carinata gausapata is rare in every unit except 

the Timms Point silt (pi. 32, fig. 13). M. tuberosa i? 

most abundant in the Lomita marl. M. carinata 

gausapata appears to intergrade with M. carinata 

proper, but it Lias a more northern range. Specimens of 

M. tuberosa from the San Pedro sand slightly larger than 

Recent shells were named M. tuberosa "major" by 

Oldroyd. Carpenter 43 thought that "Nassa" pedroana, 

based on Pleistocene material from San Pedro, may be 

the same as M. carinata gausapata. The type is lost. 

An Amphissa that occurs in all the units is identified 

as A. versicolor. A large stout species, larger and 

stouter than A. reticulata, was found only in the Palos. 

Verdes sand at Arnold's Crawfish George's locality 

and is identified as A. columbiana. It is recorded 

from other Palos Verdes localities as well as from the 

Timms Point silt and San Pedro sand. A species from 

the San Pedro sand described by Arnold as A. ventricosa 

is considered to be A. undata, though the type is some 

what stouter than most Recent A. undata. It is not 

represented in the collections at hand. 

Anachis pencillata, which is recorded from the San 

Pedro sand, was found in deposits on the fourth 

terrace at locality 86. A. arnoldi ("minima"}, from 

the Palos Verdes sand, is considered a synonym of 

A. pencillata. The type of A. arnoldi is, however, 

rather large and stout. 

Aesopus chrysalloides occurs in the San Pedro sand, 

in deposits on the fourth terrace at locality 86, and in 

the Palos' Verdes sand. A. idae, the type and only 

specimen of which is from the San Pedro sand, is 

large and thick-shelled and appears to lack spiral 

sculpture above the lower part of the body whorl. 

It is not known to be living. 

The type of the columbellid that Arnold described as 

Columbelta solidula var. praecursor is apparently no 

longer in the National Museum. "Columbella" solidula 

is considered a Strombina. It is not known whether 

the fossil from the Palos Verdes sand is related to it. 

« Carpenter, P. P., op. cit. (British Assoc. Adv. Sci. Rpt. 1863), p. 590,1864. 


OLIV1DAE 

Olivella biplicata is abundant, at least locally, in all 

the units. Specimens from the Lomita marl are larger 

than others; those from the Timms Point silt are worn 

or worn and broken. 

A small, moderately slender species that has a 

moderately thick and definitely limited parietal callus 

is identified as 0. pedroana. There has been much 

confusion concerning this name, as the type is lost 

arid the original description and figure are poor. It 

was based on material from the so-called post-Pliocene 

or Recent formation near the mouth of the Los Angeles 

River 44 before the lower course of the river was changed, 

that is, from the Palos Verdes sand. A specimen 

'selected from a lot of 22 collected at locality 113 

(Arnold's lumber yard locality) is designated the 

neotype (pi. 35, fig. 22). It agrees reasonably well 

with Conrad's description and figure. 0. pedroana 

occurs in the San Pedro sand but is more abundant in 

the Palos Verdes sand. The recently described 0. pycna*6 

(type locality, Bolinas Bay) is probably a form of 

0. pedroana. It is stouter than 0. pedroana and has a 

thicker parietal callus. Recent shells in the National 

Museum, representing 0. pycna from localities between 

Bolinas Bay and San Quentin Bay, are arranged under 

0. intorta. The type locality of that species is San 

Juan, .presumably San Juan del Sur., Nicaragua, and 

the description indicates that it is quite different from 

0. pycna. A slender Olivella that has a thin or moder 

ately thick parietal callus occurs in all the units. It is 

the species identified as 0. baetica. 

' MARGINELLIDAE 

Plyaliiia californica occurs in the Lomita marl, the 

terrace deposits, and the Palos Verdes sand and is 

recorded from the San Pedro sand. H. jewettii was 

found in the San Pedro sand and is recorded from the 

second terrace and the Palos Verdes sand. Specimens 

from the San Pedro sand that have minor supplementary 

columellar folds were given the varietal name H. 

jewettii nanella by Oldroyd. A smaller and more 

slender form that occurs in the Lomita marl, the terrace 

deposits, and the Palos Verdes sand is probably H. 

regularis. 

The minute Cypraeolina pyriformis is the most wide 

spread and locally the most abundant marginellid, 

having been found in all the units. 

TURR1DAE 

Gastropods of the family Turridae, represented by 

numerous genera and species but by relatively few 

specimens, have not been identified. Forty-six species 

and varieties are recorded from the Pleistocene strata 

of the San Pedro district. Nine of these, or 3, depend 

ing on the acceptance of questionable synonyms, are not 

reported to be living. Tun-ids are most abundant in 

the Lomita marl and Timms Point silt. The genus 

Propebela ("Beta" or "Lora") is rare except in those 

units. In the collections at hand Borsonella is repre 

sented only in those units, but it is recorded from the 

Sa.n Pedro sand. "Taranis" likewise is represented only 

in the Lomita marl and Timms Point silt in the collec 

tions at hand, but it is recorded from the San Pedro 

44 Blake, W. P., Geological report [Williainson's reconnaissance in California]: 

U. S. Pacific R. R. Expl., 33d Cong. 2d sess., 5 Ex. Doc. 78 and H. Ex. Doc. 91, vol. 

5, pt. 2, p. 186, 1857. 

45 Berry, S. S., An undescribed Californian Olivella: Malacol. Soc. Proc., vol. 21, 

pp. 262-265, 1 fig., 1935.'


sand and from the Palos Verdes sand at Arnold's 

Crawfish George's locality. 

TEREBRIDAE 

Terebra pedroana has a restricted stratigraphic and 

geographic distribution. It was not found in the 

Lomita marl or Timms Point silt, occurs in the San 

Pedro sand only at localities 49 and 49a, is represented 

in terrace deposits at locality 86 and by a fragment from 

locality 105, and is widespread and abundant in the 

Palos. Verdes sand at locality 112 and farther north. 

Virtually all the specimens have the strong sutural 

band of the variety T. pedroana ''philippiana." 

CON1DAE 

Conus californicus, the only species of the genus 

living on the California coast, occurs in all the units. 

Timms Point specimens are, however, rare and are worn 

and broken. The largest specimens were found in the 

Lomita marl and San Pedro sand. Oldroyd proposed 

the varietal name C. californicus j'ossilis for large shells 

from the San Pedro sand. The largest fossils are not 

quite as large as the largest Recent shell in the National 

Museum collection (length 42 millimeters). 

TECT1BRANCHIATES 

Only one of the tectibranchiate gastropods collected 

has been identified. Acteon breviculus (pi. 30, fig. 4; 

type locality, off Santa Rosa Island, 53 fathoms), 

heretofore unreported as a fossil, was found in the 

Lomita marl at localities 54c and 54g. This species 

belongs to a group of small moderately deep-water forms 

for which the name Microglyphis 46 was proposed. 

This group should doubtless be given generic rank. 

The recently described but unfigured A. schêncki^1 from 

^marl of the Lomita overlying the algal bed at Hilltop 

quarry, is presumably the species identified in this 

report as A. breviculus. 

Sixteen other species and varieties of tectibranchs 

are recorded as Pleistocene fossils from the San Pedro 

district. One of these, Acteocina tumida, from the 

San Pedro sand is not reported living, but the specimen 

on which it \vas based is probably a monstrosity. 

Melampus olivaceus, which lives on tidal flats, was 

found in the San Pedro sand at locality 49 and occurs in 

the Palos Verdes sand at locality 112 and other 

localities farther north and northwest. 

The high form of Williamia peUoides, heretofore un 

recorded from the San Pedro district, is represented by 

an incomplete specimen from the Lomita marl at 

locality 54g. 

The pulmonate limpet Gadinia reticulata, recorded 

from the second terrace and the Palos Verdes sand,48 is 

widespread in terrace deposits. 

Fresh-water pulmonates of the genera Helisoma, 

Gyraulus, and Physa are represented by a few specimens 

from the Palos Verdes sand at Arnold's lumber yard 

locality (locality 113) and other localities farther north 

« Dall, W. H., Illustrations of new, unfigured, or imperfectly known shells, chiefly 

American, in the U. S. National Museum: U. S. Nat. Mus. Proc., vol. 24, p. 512, 

1902. Type, Acteon curtulus Dall, Recent, Magellan Strait. 

« Berry, S. S., New Mollusca from the Pleistocene of San Pedro, Calif., II: Bull. 

Am. Paleontology, vol. 27, No. 101, p. 3,1941. 

« Chace, E. P., and E. M., An unreported exposure of the San Pedro Pleistocene: 

Lorquinia, vol. 2, No. 6, p. 42,1919. Arnold, Ralph, op. cit. (California Acad. Sci. 

Mem., vol. 3), p. 197, 1903. 

and northwest. They are recorded also from the San 

Pedro sand. 49 , 

PELECYPODS 

NUCULID A F, 

A sculptured Nucula designated by Arnold N. supra- 

striata was found in deposits on the second terrace at 

Malaga Cove (locality 105), is abundant and wide 

spread in the Palos Verdes sand, and is recorded from 

the San Pedro sand. The fossils appear to be identical 

with Recent shells from San Francisco, San Pedro Bay, 

and Catalina Island arranged under N. exigua in the 

National Museum collection. Schenck 50 considered 

them to be larger and to have less pronounced radial 

sculpture than Recent shells from the Pacific coast of 

North America identified as ^V. exigua, the type locality 

of which, "Bay of Caracas," is equivocal. - A form from 

Lower California localities is smaller than the fossils and 

has generally stronger radial sculpture. Should that 

form prove to be N. exigua it appears preferable to cite 

the fossils and the Recent California form as N. exigua 

suprastriata. Arnold attributed the name suprastriata 

to Carpenter. A slightly inperfect right valve and a 

fragment of a left valve dredged at a depth of 30 fathoms 

at Catalina Island (U. S. Nat. Mus. 23247) are labeled 

as types of Carpenter's suprastriata. As pointed out 

by Grant and Gale, Carpenter evidently never published 

the name, which is to be attributed to Arnold. His 

figured specimen from Los Cerritos, or Signal Hill, 

appears to be lost, 51 and a neotype should be selected 

from that locality. 

A small elongate smooth species, Nucula aff. N. 

cardara, from the San Pedro sand at localities 30 and 

48 is probably a small form of N. cardara (type locality, 

off San Diego, 1,090 fathoms), the type of which has 

been figured recently. 52 A minute smooth Nucula 

from the Lomita marl at locality 42d and the San 

Pedro sand at locality 65 and a shorter form from the 

Timms Point silt at locality 32a are evidently new 

species. No smooth Nucula has been recorded hereto 

fore from the San Pedro district. 

Acil'a castrensis, the only species of the genus living 

on the California coast, is abundant locally in the 

Lomita marl, abundant in the Timms Point silt, occurs 

in the San Pedro sand at localities 30, 48, and 64, and 

is represented by a doubtfully identified fragment at 

each of two Palos Verdes localities, 111 and 121. A 

specimen from the Timms Pc/int silt has been illustrated 

recently. 53 

NUCTJLANIDAE 

Cyrilla munita, not previously found in the San 

Pedro district, occurs in the Lomita marl at localities 

54g, 57a, 67, and 71 and in the Timms Point silt at 

locality 32a. The type material, consisting of three 

valves dredged at a depth of 30 fathoms off Catalina 

Island, is in the National Museum (23243).- "Nucula" 

petriola, from 53 fathoms off Santa Rosa Island, is a 

synonym. 54 

« Arnold, Ralph, op. cit., pp. 195, 196. 

s° Schenck', H. G., Revised nomenclature for some nuculid pelecypods,: Jour 

Paleontology, vol. 13, pp. 36-37,1939. 

« Schenck, H. G., op. cit., p. 36. 

«' Schenck, H. G., op. cit., p. 34, pi. 5, figs. 12,14,18, 21. 

" Schenck, H. G., Nuculid bivalves

ANOM1IDAE 

The Recent California species identified as Anomia 

peruviana, occurs locally in the San Pedro sand north 

and northwest of San Pedro at localities 49a, 56, 58a, 

and 59, being abundant at localities 58a and 59. In the 

Palos Verdes sand it was found at locality 112 and ait 

almost every locality farther north and northwest) 

being particularly abundant at localities 125, 131, and 

132 on the south limb of the Gaffey anticline. 

Monia macroschisma, the only other anomid in the 

collections, is represented in all the units except the 

terrace deposits. 

AKC1DAE 

Area sisguocensis, based on material from the upper 

Pliocene of the Santa Maria Basin, is recorded from the 

Lomita marl at Hilltop quarry 55 but is not represented 

in the collections at hand. 

Anadara perlabiata (pi. 35, figs. 23, 24), the only 

arcid in the collections at hand, was found in the Palos 

Vordes sand during the field work for this report and 

also by Arnold. It is rare, however, as it is represented 

by only a small left valve and an umbonal fragment of 

another small left valve, both from locality 124. This 

species is assigned to the subgenus Cunearca, Anadara 

proper being unknown in the latitude of San Pedro 

after the upper Pliocene. The name A. perlabiata was 

proposed by Grant and Gale for the more familiar 

"Area labiata," which is preoccupied by usage in the 

Portland Catalogue. The names in that publication 

accompanied by a citation to an illustration are now 

generally considered valid. 

GLYCYMERTDAE 

Glycymeris profunda (pi. 30, figs. 5-8) is widespread 

in the Lomita marl, being abundant in the algal bed 

at Hilltop quarry, and is represented in the San Pedro 

sand by a fragment from locality 47 and by numerous 

specimens in Oldroyd's Nob Hill collection at the 

National Museum (his Q. septentrionalis}. It is char 

acterized by strong inflation, pronounced height, 

narrow full urnbo, and markedly asymmetric ligament 

area. Some specimens (pi. 30, figs. 5, 6) have a more 

pronounced posterior truncation than others (pi. 30, 

figs. 7, 8). Well-preserved specimens, such 'as that 

shown, on plate 30, figures 7, 8, have microscopic radial 

striae, slightly worn specimens are smooth, and those 

that arc more worn or corroded are ribbed, the usual 

condition. A specimen in the Nob Hill collection 

shows a faint pattern of irregular zigzag brown color 

bands. When this report was first prepared Q. prqfunda 

was thought to be extinct, but it has been found at 

depths of 25 fathoms off Redondo and 200 fathoms off 

Catalina Island. 66 Described by Ball 57 in 1879 on the 

basis of three corroded valves from San Diego (U. S. 

Nat. M'us. 7935), it has not appeared in lists of California 

Pleistocene moUusks since then, is omitted in the Grant 

and Gale catalog, 58 and was not illustrated until the 

appearance of Willett's recent paper. Two of the 

specimens in the type lot, the more perfect (lectotype) 

of which has a length of 30.3 millimeters and a height 

of 32.2 millimeters, are larger than any from the Lomita 

' Rclnhart, P. W., Three new species of the pelecypod family Arcidae from the 

Pliocene of California: Jour. Paleontology, vol. 11, p. 183,1037. 

M Willctt. George, Northwest American species of Flycimeris: Southern California 

Acad. Sci. Bull., vol. 42. pt. 3, pp. 111-113, pi. 11, figs. 3, 3a, 1943 [1944]. 

« Dall, W. 11., Fossil mollusks from later Tertiaries of California: U. S. Nat. 

Mus. Proc., vol. 1. p. 13, 1879. 

«' Grant, U. S., IV, and Gale, H. E., Catalogue of the marine Pliocene and Pleisto 

cene Mollusco of California: San Diego Soc. Nat. History Mem., vol. 1, 1931. 


marl but are scarcely larger than the largest from the 

San Pedro sand. The type material was collected 

evidently from the Pleistocene strata .overlying the 

Pliocene San Diego formation at Pacific Beach. 89 

The species is presumably rare in the type region, for 

it is not represented in numerous collections of Pleisto 

cene fossils from Pacific Beach and other localities in 

and near San Diego. The high full umbo of Arnold's 

figure of G. "barbarensis" from the Palos Verdes sand 

suggests 0. profunda, but the relative height is not 

great enough for the typical form. The specimen of 

6. barbarensis figured in volume 7 of the Pacific Rail 

road Reports is in the National Museum (13358). It 

is imperfect and poorly preserved in a matrix of hard 

sandy limestone and is probably a small specimen of 

the species Gabb later described as G. veatchii. It 

therefore is probably Paleocene (Eocene of, Dall's 

nomenclature), as Dall thought, or Upper Cretaceous. 

A label glued to the rock reads "Glpssus (Peciunculus) 

collinus Con., shore between San Luis and Santa 

Barbara." Antisell, however, recorded it from the 

Simi Hills. The figured G. barbarensis of volume 6 of 

the Pacific Railroad Reports is not known to be exant. 

It was listed from Santa Barbara, is presumably not 

conspecific with the G. barbarensis of volume 7, as 

Dall thought, and is presumably from the Pleistocene 

Santa Barbara formation. It has the relative dimen 

sions of the Recent G. subobsoleta. The geologic 

reports, including the paleontology, of both volumes 

bear the date 1856. Volume 6 was transmitted for 

publication, however, May 6, 1857, and volume 7 

February 9, 1857. Both were issued probably some 

time during 1857. Until evidence .establishing priority 

is found the G. barbarensis of volume 6 is herewith 

arbitrarily given precedence. This action may dispose 

of the troublesome name, as the G. barbarensis of 

volume 6 is a probable synonym of G. subobsoleta, and 

the G. barbarensis of volume 7 is automatically a 

homonym. 

A smaller, less inflated, and more elongate Glycymeris, 

Arnold's G. septentrionalis, is identified as G. corteziana 

(type locality, Cortez Bank, 67 fathoms). It occurs 

locally in the San Pedro saiid at localities 49, 49a?, and 

56?, and in deposits on the second terrace at locality 105 

and is widespread but uncommon in the Palos Verdes 

sand. G. corteziana is doubtless a small race of G. 

subobsoleta, ranging farther south (Forrester Island, 

Alaska to Magdalena Bay, Lower California) than G. 

subobsoleta proper (Alaska to Oregon). In the collection 

of the National Museum G. corteziana is represented by 

specimens from depths of 8 to 90 fathoms. G. migue- 

liana (type locality, San Miguel Island, 53 fathoms) is 

considered a synonym. 

Philobrya setosa, heretofore recorded only from the 

San Pedro sand, occurs in the Lomita marl at Hilltop 

quarry (localities 53, and 53b), in the San Pedro sand 

at locality 30, and in deposits on the sixth terrace at 

locality 78. In each collection it is represented by one 

valve. 

MYTILIDAE 

Small broken valves of Mytilus californianus were 

collected on the fourth terrace at localities 83 and 85 and 

on the second terrace at locality 95. This species is, 

however, not as common in terrace deposits as might 

" Dall, W. H., Distribution of California Tertiary fossils: Op. cit., p. 29.

80 

be expected from its present abundance along rocky 

coasts in southern California. It was, not found in the 

other Pleistocene units but is recorded from the San 

Pedro sand. 

A small Botulina 60 ["Gregariella"] is represented by 

numerous specimens from the second terrace at locality 

105. They are identical with a form, dredged at depths 

of 10 to 50 fathoms along the coast of southern Califor 

nia, labeled Modiolus opifex in the National Museum 

collection. That species was based on material from 

the Island of Minorca, and it is doubtful whether the 

California species is conspecific. The genus has not 

been recorded heretofore from the California Pleistocene. 

Septifer bifurcatus is one of the few widespread locally 

abundant pelecypods in terrace deposits. It is not 

represented in collections from other units but is re 

corded from the San Pedro sand. 

PECTINIDAE 

Pecten stearnsii occurs in the' Lomita marl (pi. 30, 

figs. 9, 10) and in the Timms Point silt (pi. 32, figs. 14, 

15) and is probably represented in the San Pedro sand 

by small left valves from localities 58 and 64. Most of 

the valves from the Lomita marl and Timms Point silt 

are broken. This species was based on material from 

upper Pliocene strata in the San Diego formation at 

Pacific Beach, near San Diego. It is closely related to 

P. diegensis from moderate depths (14 to 60 fathoms) 

off the coast of southern California. The fossils reach 

a slightly larger size than Recent shells and have a few 

more ribs. On the interior of right (inflated) valves of 

P. diegensis the projections corresponding to .the exte 

rior interspaces are bordered near the margin of the 

valve by a narrow flange, as on the interior of left (flat) 

valves. Left valves of P. stearnsii have the interior 

flange, but on right valves the flange is absent or is 

weakly developed only near the anterior and posterior 

ends of the valve. Whether the Recent form is to be 

assigned specific or varietal rank is a matter of indivi 

dual preference. If it is assigned varietal rank, it is 

to be cited as P. stearnsii diegensis , as was done by Grant 

and Gale, for stearnsii has priority. P. stearnsii sur 

vived from the Pliocene into the Pleistocene and then 

appears to have become extinct. These two forms are 

more similar to Pecten proper than any other California 

Pleistocene and Recent species. The right valve, how 

ever, is not so inflated as in Pecten proper, the ribs are 

more angular, and secondary ribs are absent on the 

main part of the shell and on the ears. 

Three imperfect valves and a fragment of Pecten 

vogdesi (pi. 35, figs. 2-4) were collected from deposits 

on the second terrace at Malaga Cove (locality 105). 

The type of this species is from the Palos Verdes sand, 

but it is rare in that unit, as Arnold had only one valve, 

and none was found during the field work for this re 

port. It has been recorded recently from Pleistocene 

strata near Playa del Rey. 61 P. vogdesi is' closely re 

lated to P. cataractes from the Gulf of California and 

may be indistinguishable from the Recent form. Ac 

cording to Arnold, the left valve of P. vogdesi has no 

secondary riblet in the interspaces or has faint riblets. 

The incomplete left valve shown on plate 35, figure 3, 

has one strong riblet and several faint riblets. On some 

Recent shells riblets are faint or absent in some or 

«° JDall, W.'H., A preliminary catalogue of the shell-bearing marine mollusks and 

brachiopods of the southeastern coast of the United States: U. S. Nat. Mus. Bull. 37, 

p. 38, 1889. Monotype, "Modiola opifex Say," Recent, Cape Hatteras to Cuba 

(1=Chima coralliophaga Omelin). 

«' Willett, George, op. cit. (San Diego Sbc. Nat. History Trans., vol. 8, No. 30), 

p. 387, 1937. 

most of the interspaces. P. coalingaensis,®2 a close 

relative from the upper Pliocene San Joaquin forma 

tion of the San Joaquin Valley, lacks -secondary riblets 

on the left valve. These fossil and Recent pectens do 

not represent Pecten proper. They are to be assigned 

to the subgenus Euvola, the type of which has weaker 

ribs on the right valve and strong secondary ribs on 

the left valve, or to a minor group under Euvola. 

Aequipecten circularis is widespread and abundant in 

the Pal'os Verdes sand at locality 112 and localities 

farther north and northwest and is represented by a 

doubtfully identified fragment from the Lomita marl 

at locality 61. Whether the California Pleistocene and 

Recent form is to be distinguished from A. circularis 

proper" (type locality, Gulf of California) as the variety 

A. circularis aeguisulcatus appears to be doubtful. 

The type of "Pecten" newsomi, from Pleistocene strata 

at Los Cerritos, or Signal Hill, is a young left valve of 

this species. "P." compactus and "P." subventricosus, 

both from a locality near Ventura and doubtless of 

Pleistocene age, are additional synonyms. A. circularis 

is the type of the subgenus Plagioctenium, which has a 

more inflated right valve than Aequipecten proper and 

lacks secondary radial riblets. In coastal California 

Plagioctenium is unknown before the Pliocene. In 

tropical America, however, it is widespread in the 

Miocene. It occurs .in the Imperial formation of the 

Colorado Desert, of disputed Miocene or Pliocene age. 

Chlamys hastatus is abundant in the Lomita marl 

and Timms Point silt, occurs in the San Pedro sand at 

localities 64 and 65, and is recorded by Arnold from 

the Palos Verdes sand at his Crawfish George's locality. 

Both fossil and Recent shells show perfect gradation 

between C. hastatus proper, characterized by well-dif 

ferentiated primary ribs that bear well-developed scaly 

lamellae, and C. hericius, which lacks those characters. 

Chlamys islandicus jordani occurs in the Lomita 

marl, is abundant in the Timms Point silt (pi. 32, fig. 

16), and is represented in the San Pedro sand at local 

ity 47. Based on material from the Timms Point silt, 

it is considered a form of C. 'islandicus, of small or 

medium size, that has split primary ribs, especially on 

the right valve. It differs from C. islandicus hindsii 

principally in the. absence of scaly lamellae on the ribs. 

As in other forms of the C. islandicus group and in 

other species of Chlamys, part or all of the shell has 

microscopic punctation. The specimen shown on plate 

32, figure 16, is exceptionally large. C. islandicus 

jordani is living in Puget Sound but is not known to 

be living farther south. 

A small form of the Chlamys islandicus group that 

has numerous narrow scaly ribs is identified as C. 

islandicus hindsii (-\-navarchus). It occurs in the San 

Pedro sand at locality 48 and is represented in the 

Palos Verdes sand by a worn valve from locality 111 

and a young valve from locality 113. C. islandicus 

hindsii is somewhat intermediate between C. islandicus 

proper and C. hastatus. 

Chlamys opuntia is represented by fragments from 

the Lomita marl at localities 53 and 54g. Based on 

material from the upper Pliocene part of the San Diego 

formation at Pacific Beach, it is characterized by very 

numerous scaly ribs of almost uniform width formed by 

splitting and intercalation. It is related doubtless to 

C. islandicus and might be considered another form of 

the C. islandicus group. Like Pecten stearnsii, C. 

62 Stewart, Ralph, in Woodring, W. P., Stewart, Ralph, and Richards, R. W., 

Geology of the Kettleman Hills oil field, Calif.: U. S. Geol. Survey Prof. Paper 195, 

p. 90, pi. 13, figs. 1, 2, 17, 18; pi. 16, fig. 4, 1940 [1941].

opuntia survived from the Pliocene into the Pleistocene 

and since then appears to have become extinct. 

The new name Chlamys anapleus (pi. 34, fig. 15) is 

proposed, for a small Chlamys represented by a valve 

from the Lomita marl at locality 53 and another from 

the San Pcd.ro sand at locality 30. It has 10 or 11 wide 

primary ribs, a weak secondary riblet in most .of the 

interspaces, and is sculptured with microscopic punc- 

tation. The ventral margin of the type is bent, per 

haps to form at a later stage a swelling, as in C. parme- 

leei. On the imperfect Lomita specimen some of the 

ribs are grooved. This Chlamys also might be con 

sidered a form of the C. islandicus group at the opposite 

extreme from C. opuntia in width of ribs. It was iden 

tified by Arnold as Pecten (Chlamys) hericeus var. 

strategus. "P. 11 strategus, from Alaska, is considered a 

synonym of C. islandicus beringianus, a wide-ribbed 

Alaskan variety of C. islandicus. The ribs of C. 

anapleus do not enlarge so rapidly as in C. islandicus 

beringianus, and secondary ribs are weak or absent. 

The Pliocene C. parmeleei and its close Pliocene relative 

C. etckegoini have only half as many primary ribs. 

C. anapleus is not known to be living. 

Patinopecten caurinus is one of the widespread and 

characteristic species of the Timms Point silt (pi. 32, 

fig. 17, pi. 33, fig. 1). It occurs, however, in the Lomita 

marl at localities 62b (doubtfully identified fragments) 

and 67 (small imperfect valve) and in the San Pedi*o 

sand at locality 30 at Deadman Island (small valves). 

Though Arnolcl. 63 did not mention material from the 

Palos Verdes sand in the systematic part of his memoir, 

he listed P. caurinus from his Crawfish George's 

locality. In his consolidated list on page 37 it is re 

corded from his lumber yard locality but is riot included 

in the fauna! list from that locality 011 page 27. All 

the largo specimens collected during the field work on 

which this report is based are broken, the large speci 

men shown on plate 32, figure 17, being selected from 

an old collection from the Timms Point silt at Deadman 

Island. None of the fossils are a large as large Recent 

shells from Alaska and Puget Sound. Young well- 

preserved valves show traces of camptonectes sculpture 

on the smooth umbonal part. At the present time 

this species ranges from Cordova, Alaska, to Point 

Rcycs, central California.64 

Leptopecten latiauratus, including the variety L. 

latiauratus monotimeris, is locally abundant in the 

San Pedro sand, is represented by numerous specimens 

from the second terrace at locality 105 and by frag 

ments from the fourth terrace at .locality 86, and is 

widespread and abundant in the Palos Verdes sand. 

A small imperfect valve from the Lomita marl at 

locality 73 and another from the Timms Point silt 

that lias narrow-crested ribs represent probably this 

species. The variety L. latiauratus cerritensis ("frag- 

ilis"), based on material from the Palos Verdes sand, 

has fewer and wider ribs than L. latiauritus proper. 

The variety L. latiauratus delosi, based on material 

from the San Pedro sand, has strong concentric iamei- 

lae. Neither form is in the collections at hand. 

A new species of Pseudamussium is represented by 

imperfect and young valves from the Lomita marl at 

localities 54c, 54e, and 62b and probably by worn 

valves from the Timms Point silt at locality 32d. It is 

larger than P. bistriatus (type locality, oft' San Diego, 

"Arnold, lltvlph, Tho paleontology and stratigraphy of the marine Pliocene and 

cistocono of San Pedro, Calif.: California Acad. Sci. Mem., vol. 3, pp. 25, 37, 1905. 

°< Mortlom, L. G., Addition to the range of Pecten caurinus Gould: Nautilus, vol. 

64, pp. 68-69,1940. 


822 fathoms), and has weaker concentric sculpture. 

These two species do not represent Pseudamussium 

proper, which has a thicker shell and coarse radial 

sculpture on the ears. The genus has not been recorded 

heretofore from the California Pleistocene. 

The genus Hyalopecten, also heretofore unrecorded 

from the California Pleistocene, is represented by a 

small species identified as H. vancouverensis. Imper 

fect valves and fragments were found in the Lomita 

marl at localities 54e, 54g (identification doubtful), 

and 62b and well-preserved valves in the Timms Point 

silt at localities 32c (pi. 33, fig. 2), 32d, and 44 (pi. 33 

fig. 3). This species represents the subgenus Delecto- 

pecten. As in other fossil and Recent species from 

California, the strength of the radial sculpture is var 

iable. 65 

A weakly sculptured form of Propeamussium alasken- 

sis occurs in the Lomita marl at Lomita quarry (locality 

62b). The Propeamussium from the San'Pedro sand 

at Deadman Island recorded by Arnold as Pecten 

(Propeamussium) riversi is doubtless P.' alaskensis, as 

Grant and Gale thought, but specimens have not been 

examined. 

OSTREIDAE 

A falcate plicate oyster represented by a right valve 

from the Lomita marl at locality 61 is identified as 

Ostrea megodon cerrosensis (pi. 30, fig. 11). It is rela 

tively wide and has broad shallow plications. Accord 

ing to Sowerby's illustrations, 66 0. megodon proper 

(type locality, Peru) is larger and has narrower and 

deeper plications. A small shell from Peru, the only 

one available, has such plications, and large shells from 

Lower California are similar to Sowerby's figures. The 

Lomita marl specimen has plications like those of 

0. megodon cerrosensis from the Pliocene of Cedros 

Island, Lower California, but the shell is wider. No 

megodon-likQ oyster is living along the Pacific coast 

north of Scammon's Lagoon, Lower California, and 

this is the first record from the California Pleistocene. 

This oyster is probably not so rare as the collections 

at hand indicate, for the weighmaster. at Sidebotham 

sand and gravel pit near Lomita quarry has several 

specimens. 

Ostrea lurida, the Recent California species, occurs 

in the San Pedro sand, being locally abundant, and was 

found at almost all Palos Verdes localities. A minute 

shell from the Timms Point silt at locality 66, another 

from the third terrace at locality 92, and numerous 

small shells from the second terrace at locality 105 are 

presumably that species. 

CKASSATELLIDAE 

Eucrassatella fluctuata (pi. 31, figs. 1-8) is character 

istic of the Lomita marl, occurring at localities 53, 53a, 

54g, and 69 and being most abundant in the algal bed 

at Hilltop quarry. It is represented, however, in the 

Timms Point silt by a small thin broken left valve from 

locality 33 and probably in the San Pedro sand by a 

fragment of a small left valve from locality 64 that has 

more closely spaced concentric lamellae than other 

specimens. The type of E. fluctuata is a small right 

valve from Catalina Island (length 8.2 millimeters). 

There are no large Recent shells hi the National Museum 

es Woodring, W. P., Lower Pliocene mollusks and echinoids from the Los Angeles 

Basin, Calif.: U. S. Qeol. Survey Prof. Paper 190, pp. 35-42,1938. 

«« Sowerby, Q. B., Conchologia Iconica, Ostrea, PI. 12, figs. 24a, 24b, 1871


collection. " Crassatellites" lomitensis, based on a large 

valve from the Lomita marl, is a synonym. 

Crassinella branneri (pi. 36, figs. 1-6) is one of the 

most abundant of the southern species characteristic 

of the Palos Verdes sand. It was found at 16 localities 

between localities 112 and 135, inclusive, and is locally 

abundant. It occurs also in deposits on the fourth 

terrace at locality 86. As shown by the illustrations, 

strong concentric undulations are confined to the 

umbonal part of the shell or cover the entire shell. 

Faint microscopic radial striae, are visible on unworn 

specimens. The type material is from the late Pleisto 

cene strata at Los Cerritos, or Signal Hill, correlated by 

Arnold with the Palos Verdes sand. The Recent 

Pacific coast Crassinellas in the National Museum are 

not satisfactorily determined. C. branneri is repre 

sented by a typical large bleached valve dredged off 

Coronado, San Diego, by two worn valves of medium 

size and a small fresh paired shell from a depth of 7 

fathoms in San Diego Bay, and by a small race or a 

closely related species from Scammon's Lagoon, Lower 

California. Whether the typical large shell from San 

Diego is a Recent shell or a detrital Pleistocene fossil 

may be determined by future dredging. The small 

fresh paired shell indicates that C. branneri or a closely 

related species is living at San Diego. 

Crassinella nuculiformis 67 (pi. 36, figs. 7-10) is smaller 

and more elongate than C. branneri. It is the " Gouldia 

aff. varians" of the preliminary paper 68 on the terraces. 

This species has concentric undulations on the umbonal 

area only, or on a larger part of but not the entire shell 

of adults. Very faint microscopic radial striae are 

visible on unworn specimens. C. nuculiformis is 

closely related to a form in the National Museum 

collection labeled C. varians, from Cape St. Lucas and 

La Paz, at the south end of Lower California, but it is 

larger, less elongate, and has a wider lunular area. 

This Recent form is evidently not C. varians, 69 which 

was based on material from Mazatlan on the Pacific 

coast of Mexico. The only available specimens from 

Mazatlan are 3 minute trigonal valves glued to a card 

by their exterior surfaces. Photographic reproduc 

tions of Carpenter's drawings in the files of the National 

Museum also show the interior of 2 small trigonal shells. 

C. nuculiformis is abundant in the Palos Verdes sand, 

having been found at 12 localities between localities 

114 to 135, inclusive, but is less abundant than C. 

branneri. It occurs also in deposits on the second 

terrace at locality 105, where it is represented by 

numerous specimens slightly smaller than those from 

the Palos Verdes sand. The C. "varians" recently 

recorded from late Pleistocene strata near Playa del 

Rey 70 is this species. 

A Crassinella has been reported recently from Coos 

Bay, Oreg. 71 Discovery of breeding specimens is desira 

ble to confirm this remarkable 1,000-mile northward 

extension of the range of the genus on the Pacific coast. 

CARDIT1DAE 

Glans subquadrata is one of the few widespread and 

abundant pelecypods in terrace deposits. It is present, 

67 Berry, S. S., New Mollusca from the Pleistocene of San Pedro, Calif., I: Bull. 

Am. Paleontology, vol. 25, No. 94a, p. 3, pi. 1, ftps. 1, 2, 1940. 

«> Woodring, W. P., Fossils from the marine Pleistocene terraces of the San Pedro 

Hills, Calif.: Am. Jour. Sci., 5th ser., vol. 29, pp. 301, 303, 1935. 

68 Carpenter, P. P., Catalogue of the Reigen collection of Mazatlan shells, pp. 

83-84,1857. 

70 Willett, George, op. cit. (San Diego Soc. Nat. History Trans., vol. 8, No. 30, p. 

387, 1937. 

71 Keen, A. M., New pelecypod species of the genera Lasaea and Crassinella: 

Malacol. Soc. Proc., vol. 23, pp. 31-32, pi. 2, figs. 11, 12, 1938. 

but uncommon, in the Lomita marl, San Pedro sand, and 

Palos Verdes sand. The only Palos Verdes material 

consists of one valve from each of two localities, 107 and 

108. If this species is not assigned to Cardita, the sub 

stitute names Cardita carpenteri 72 and C. minuscula are 

unnecessary, for it is improbable that either Conrad's 

or Gabb's Cardita subquadrata is to be assigned to Glans. 

The type material is from Neah Bay, Wash. 

Miodontiscus prolongatus occurs in the three lower 

Pleistocene units but is common only in the algal bed 

at Hilltop quarry. "Venericardia" yatesi, from the 

Pleistocene Santa Barbara formation, is a synonym. 

Though the range of M. prolongatus is cited as Alaska 

to San Diego, it is not known to be living as far south 

as San Pedro. The southernmost locality represented in 

the collection of the National Museum is off the Oregon 

coast, depth 50 fathoms. The type material of this 

species also is from Neah Bay, Wash. 

Two groups of Cyclocardia are recognized in the 

Pleistocene strata, one group embracing strongly ribbed 

forms, the other embracing a weakly ribbed species. 

The strongly ribbed forms are identified as Cyclocardia 

aff. C. occidentalis, the weakly ribbed species as C. 

barbarensis. 

The strongly ribbed forms are abundant in the Lomita 

marl and Timms Point silt, uncommon in the San Pedro 

sand, and rare in the Palos Verdes sand. Most San 

Pedro and Palos Verdes specimens are worn, with the 

exception of those from localities 64 and 65 and one of 

four specimens from locality 108. At least two forms 

appear to be represented among the strongly ribbed 

Cyclocardias, but their relations are uncertain. The 

common form, which is moderately or strongly inflated, 

has narrow grooves between the ribs and closely spaced 

nodes that are weak except on the umbonal part of the 

shell (pi. 31, figs. 9, 10). The largest specimens are 

from the algal bed at Hilltop quarry and are only mod 

erately inflated (pi. 31, fig. 9). A less abundant form, 

found in the Lomita and Timms Point, generally in as 

sociation with the form just described, and in the San 

Pedro at locality 65, has relatively wide grooves be 

tween the ribs, strong widely spaced nodes, and a heavy 

right middle cardinal (pi. 33, fig. 4). This form closely 

resembles Cyclocardia californica, from the upper Plio 

cene of the Santa Maria Basin, but is smaller, and the 

largest specimens are wider than Santa Maria shells of 

the same size. "Cardita" occidentalis, the type of 

which is not known to be extant, was based on material 

from the Pleistocene Santa Barbara formation at Santa 

Barbara. "Cardita" monilicosta,fTom the same forma 

tion and the same locality, is assumed to be a synonym. 

The only available specimens from Santa Barbara, one 

of which was figured by Arnold, 74 are small (length 11.2 

milh'meters), strongly inflated, and have strong ribs and 

closely spaced nodes. Small strongly inflated specimens 

from the San Pedro district resemble these small Santa 

Barbara specimens. "Cardita" ventricosa was the first 

name proposed for Recent Cyclocardias from the Pacific 

coast of the United States, and that name has been used 

for Pleistocene fossils from the San Pedro district. The 

type of Cyclocardia ventricosa, as selected by Dall, con 

sists of corresponding right and left valves (length 15.1 

73 Lamy, Edouard, Eevision des Carditacea vivants du Musfeum National d'His 

toireNaturellede Paris: Jour. Conchy]., vol. 66, p. 264,1921. 

73 Conrad, T. A., Description of eighteen new Cretaceous and Tertiary fossils: 

Acad. Nat. Sci. Philadelphia Proc., vol. 7, p. 267, 1855; Description of the Tertiary 

fossils collected on the survey [Williamson's reconnaissance in California and Oregon]: 

U. S. Paciilc R. R. Expl., 33d Cong., 2d sess., S. Ex. Doc. 78 and H. Ex. Doc. 91, 

vol. 6, pt. 2, p. 73, pi. 5, fig. 24, 1856 [1857]. 

74 Arnold, Ralph, Geology and oil resources of the Summerland district, Santa 

Barbara County, Calif.: U. S. Geol. Survey Bull. 321, pi. 14, fig. 12,1907.

millimeters) from Puget Sound. The ribs are mod 

erately strong and the nodes weak. Though it reaches 

a larger size (length 27 millimeters), the ribs and espe- 

pocially the nodes of C. ventricosa are not strong. Dall 

selected corresponding right and left valves from the 

typo lot of C. ventricosa as the type of C. stearnsii. 

Those two valves are narrower than C. ventricosa and 

have higher umbos and stronger ribs and nodes. The 

relations of the two forms are still unknown, the type of 

C. stearnsii being evidently exceptional. Strongly 

ribbed and noded Cyclocardias, resembling fossils from 

the San Pedro district and like them showing apparently 

variation in shape and in strength of ribs and nodes, 

occur along the southern California coast at depths of 

25 to 124 fathoins, a form similar to C. ventricosa oc 

curring apparently in that area at slightly greater 

depths, Gl to 339 fathoms. 'No Recent specimen avail 

able is as large as the large shells from the algal bed at 

Hilltop quarry, the largest having a length of 24.2 mil 

limeters (Cortez Bank, 90 fathoms). No large Recent 

specimen examined has the exceptionally strong widely 

spaced nodes of the californica-\ikG form shown on plate 

33, figure 4. "Venericardia >} nodulosa was based on 

small specimens or a small race that has strong closely 

spaced nodes. The nodes are generally stronger than 

on the small Santa Barbara C. occidentalis. The largest 

specimen in the type lot of C. nodulosa, dredged off 

Santa Rosa Island at a depth of 48 fathoms, has a 

length of 10.8 millimeters. 

The weakly ribbed Cyclocardia barbarensis (pi. 31, 

figs. 11, 12) was found only in the lyomita marl and 

only in. glauconitic foramimferal sand and calcareous 

sand. It is particularly abundant in the glauconitic 

foraminiferal sand forming the lower part of unit 6a 

of the section in the canyon west of Plilltop quarry 

(locality 54e) and is the only abundant mollusk in the 

glauconitic foraminiferal-sand forming unit 6a of the 

section at Lomita quarry (locality 62b). At locality 

60a it is associated with C. aff. C. occidentalis. C. 

barbarensis is more quadrate and thinner than C. aff. 

C. occidentalis and has a less massive hinge, and the 

right middle cardinal is more conspicuously grooved. 

The degree of inflation is variable. It is living off the 

Channel Islands and off Point Loma at depths of 62 to 

276 fathoms, generally 175 to 275 fathoms. The 

type lot is from a depth of 276 fathoms. Though 

recorded from'the Timms Point .silt, San Pedro sand, 

and Palos Verdes sand, (7. barbarensis is not represented 

in those units in the collections at hand. Perhaps 

some of the records are based on worn specimens of 

C. aff. C. occidentalis. 

Milneria kelseyi is represented by well-preserved 

specimens from the fourth terrace at locality 86. The 

genus has not been reported heretofore from the 

California Pleistocene. 

VES1COMYACIDAE 

The genus Calyptogena has been assigned recently 

to the Vesicomyacidae. 75 Calyptogena gibbera, based 

on material from the Timms Point silt of Deadman 

Island, has according to the description, and figure a 

greater height than C. pacifica. It is not represented 

in the collections at hand. 

» WooclrinK, W. P., op. cit. (U. S. Ocol. Survey Prof. Paper 190), p. 50,1938. 

» Cricknmy. C. H., On a now pclecypod Calyptogena gibbera: Canadian Field 

Naturalist, vol. 43, No. 6, p. 93, 1 flg., 1929. 


THYASIRIDAE 

The small Recent species identified as Thyasira 

gouldii is abundant in the Lomita marl and Timms 

Point silt but is rare in the San Pedro sand, being 

represented in that unit only by an imperfect specimen 

from Deadman Island (locality 30). Oldroyd recorded 

one specimen from the San Pedro sand at his Nob Hill 

locality. 

The relatively gigantic Thyasira disjuncta (pi. 33, 

fig. 5) is perhaps the most characteristic species of the ' 

Timms Point silt. It has not been found in any other 

unit. It is one of the few San Pedro fossils described 

at an early date and assigned to a definite locality, 

Deadman Island, where it was abundant in a zone 

known as the "Cryptodon bed." The figured specimen 

is from an old Deadman Island collection. This 

species has not been found recently at Timms Point. 

The only specimens collected during the field work for 

this report are paired but poorly preserved and are 

from locality 35, on the west side of Harbor Boulevard, 

representing strata in the Timms Point silt that are 

thought to overlie those exposed at Timms Point. 

Clark 77 recorded it, however, from unit 2 in exposures 

on the east side of Harbor Boulevard. Arnold and 

other paleontologists identified this species as T. 

bisecta, which was based on material from the Miocene 

of Astoria, Oreg. T. disjuncta is larger and more 

quadrate than T. bisecta, and the anterior end is more 

abruptly truncated. The type of T. bisecta and four 

other specimens in the Dana collection have an ex 

tended anterior end. The largest specimen has, how 

ever, a truncated anterior end, but not so abruptly 

truncated as in T. disjuncta. At the present time 

T. disjuncta is not known to be living south of the 

Oregon coast. The fossils are larger than the largest 

Recent shell in the National Museum collection (length 

65.5 millimeters). T. disjuncta is the type of Con- 

chocele. The exceptionally large size appears to .be 

the only shell character to distinguish Conchocele. 

Whether any anatomical characters are correlated 

with the large size is not known. 

Axinopsis viridis, recorded from the Timms Point 

silt, 78 is locally common in the Lomita marl and Timms 

Point silt but like Thyasira gouldii is rare in the San 

Pedro sand, being represented in that unit only by a 

few specimens from localities 30, 48, and 64. 

LUCINIDAE 

Lucinoma annulata is abundant in the three lower 

Pleistocene units, but is represented in the Palos Verdes 

sand by only one valve of medium size from locality 111. 

Well-preserved large valves were collected from the 

San Pedro sand at Deadman Island. Recent large 

shells comparable in size to those from the lower 

Pleistocene strata are not represented in the National 

Museum collection from localities south of Puget Sound. 

Epilucina californica is the most abundant and wide 

spread of the pelecypods from the terrace deposits 

older than the Palos Verdes sand. It occurs also in 

the other Pleistocene units. 

UNGTJLINIDAE 

The diplodontid ranging southward from San Diego, 

identified by Carpenter and Dall as Diplodonta sericata, 

" Clark, Alex, op. cit. (San Diego Soc. Nat. History Trans., vol. 7, No. 4), table op. 

p. 30 (locality 322), 1931. 

" Clark, Alex, op. cit.

84 GEOLOGY 'AND PALEONTOLOGY OF PALOS VERDES HILLS, CALIFORNIA 

is characteristic of the Palos Verdes sand (pi. 36, figs. 

11-14). It was found at 12 localities between localities 

114 and 142, inclusive, and also occurs in deposits on 

the second terrace at locality 105. Most of the fossils 

are smaller than Recent Lower California shells, but a 

few broken specimens arejabout as large. 

LEPTONACEA 

The leptonacid pelecypods have not been identified. 

It may be pointed out that a Lasaea, presumably L. 

cistula, is fairly common in terrace deposits. The 

genus has not been reported heretofore from the Pleisto 

cene of the San Pedro district. 

TELLINIDAE 

A small Macoma that has a short posterior end is 

identified as a small variety of Macoma calcarea (pi. 33, 

fig. 6). It is abundant and widespread in the Timms 

Point silt and is characteristic of that unit. This small 

Macoma (maximum length about 31 millimeters) 

appears to be identical with a small race of M. calcarea 

ranging from British Columbia to Monterey Bay (13 

to 51 fathoms along California coast). Perhaps it has 

been recorded as M. planiuscula 80 (Ball's M. carlottensis, 

according to Grant and Gale), but that species is less 

inequilateral. M. carlottensis (Ball's M. inftatula, 

according, to Grant and Gale) has been recorded from 

the Timms Point silt 81 but is not recognized in the 

collections at hand. 

SEMELIDAE 

Cumingia lamellosa is locally common in terrace de 

posits. It also occurs in the other units with the ex 

ception of the Timms Point silt. The only Lomita 

specimen however, is a small valve from locality 53b. 

VENERIDAE 

Dosinia ponderosa (pi. 36, figs. 15, 16), not found 

previously in the San Pedro district, is a southern 

species characteristic of the Palos Verdes sand. It was 

collected at 9 localities between localities 113 to 135, 

inclusive. All the specimens are broken and more or 

less worn. Corresponding right and left valves from 

San Biego, the only specimens in the National Museum 

collection from the present northern limit of this species, 

are small (length 61.5 millimeters). 81a 

Though Arnold reported Amiantis callosa to be rare 

in the Palos Verdes sand along the water front, it is 

widespread and locally abundant in that unit, but it 

is not known to occur in the other Pleistocene units. 

Katherinella subdiaphana (pi. 33, figs. 7-9) is common 

in the Timms Point silt. It is represented in the 

Lomita marl by a fragment from locality 54g and in 

the San Pedro sand by well-preserved specimens from 

Beadman Island at locality 30. Arnold's variety K. 

subdiaphana pedroana was based on a small left valve 

from the San Pedro sand of Beadman Island. No 

large Recent shells comparable in size to the Pleisto 

cene fossils are in the National Museum collection 

from localities south of Oregon, the largest from the 

California coast being a left valve that has a length of 

35.3 millimeters (off Santa Rosa Island, 53 fathoms). 

This species is the type of the subgenus Compsomyax, 

which lacks the anterior lateral of Katherinella proper 

and has a more strongly bifid right posterior cardinal. 

79 Keen, A. M., op. cit. (Malacol. Soc. Proc., vol. 23), pp. 25-26, pi. 2, flgs. 7-9, 1938. 

8» Willett, George, op. cit. (Southern California Acad. Sci. Bull., vol. 36), p. 61,1937. 

81 Idem. 

81 a These two valves are bleached, have no epidermis or ligament, and sand grains 

are attached to the nymph. They evidently are Pleistocene fossils. The northern 

most locality for Eecent specimens in .the National Museum collection is Scammon's 

Lagoon, Lower California. 

Ventricola fordii (pi. 31, figs. 13-15) was found only 

in the Lomita marl. It is very abundant in the algal 

bed at Hilltop quarry (localities 53, 53a), where it is 

represented by specimens ranging in length from 8 to 

77 millimeters. It is also represented by worn frag 

ments from localities 54g and 61. The largest Recent 

specimen in the National Museum collection has a 

length of 66 millimeters. Aside from Grant and Gale's 

indefinite record, this species has not been recorded 

heretofore from the San Pedro district. Ventricola is 

so closely related to Venus that subgeneric rank may 

be preferable. It has, however, finer and less distinct 

radial sculpture than Venus and a stronger anterior 

lateral pustule. 

Mercenaria perlaminosa (pi. 31, figs. 16, 17), already 

recorded from the Timms Point silt, 82 is represented 

by fragments from the Lomita marl at localities 60a, 

69, 71 and from the Timms Point silt at locality 32a. 

The figured specimen was collected from the algal bed 

at Hilltop quarry, where this species was not found - 

during the field work for this report. All the specimens 

are corroded, revealing the hidden radial sculpture. 

This species was based on material from the Pleistocene 

Santa Barbara formation and is not known to be living. 

It is closely related to M. kennerleyi, which ranges 

from Alaska to the Santa Barbara Islands, but is less 

elongate. M. kennerleyi is not represented in the 

National Museum collection from localities south of 

Carmel Bay. It is the type of the subgenus Humilaria, 

which has a less extended porterior end and a narrower 

pallial sinus than Mercenaria proper. 

Chione gnidia (pi. 37, figs. 1, 2) is another southern 

species characteristic of the Palos Verdes sand. It is 

not common, however, as it was found only at localities 

123, 134, and 135. The small l(Chione" picta 83 (pi. 37, 

figs. 3, 4) is likewise a southern species characteristic of 

the Palos Verdes sand. It is fairly common, having 

been found at 8 localities between localities 113 and 135, 

inclusive. Mr. E. P. Chace reports that it is common in 

deposits of the second terrace on Fifteenth Street near 

Leland Avenue. Heretofore unrecorded from the San 

Pedro district, this species ranges from Magdalena Bay, 

Lower California (the type locality), to Panama. The 

dark-colored interior blotch on the posterior part of the 

shell is visible on the fossils. This species is not a 

typical Chione; it represents apparently a new subgenus 

or genus. 

CARDIIDAE 

The essentially northern cardiid Cerastoderma nuttallii 

occurs in the Lomita marl, Timms Point silt, San 

Pedro sand (pi. 34, figs. 16, 17), and Palos Verdes sand. 

It is rare in the Lomita marl, as it was collected only at 

locality 65. None of the fossils are large, the figured 

specimen being the largest. All except the figured 

specimen are more or less corroded, and many are 

broken. Though moderately large Recent specimens in 

the National Museum are labeled San Pedro and San 

Biego, this species has not been found recently at or 

near San Pedro., according to local collectors. The 

name Clinocardium 84 has been proposed for the Pacific 

coast Ceras'todermae, C. nuttallii being the type. 

Trachycardium guadragenarium, which ranges from 

Santa Barbara to Lower California, occurs in the three 

83 Clark, Alex. op. cit. (San Diego Soc. Nat. History Trans., vol. 7, No. 4), table 

op. p. 30, 1931. 

w Willett, George, Two new west American pelecypods: Southern California Acad. 

Sci. Bull., vol. 43, pt. 1, pp. 20-22, pi. 8, 1944. 

s< Keen, A. M., A new pelecypod genus of the family Cardiidae:.San Diego Soc. 

Nat. History Trans., vol. 8, No. 17, pp. 119-120, 1936.

lower Pleistocene units, in deposits on the second and 

third terraces, and in the Palos Verdes sand. The 

specimen shown on plate 34, figures 18 and 19, is from 

the San Pedro sand at Deadman Island (locality 30). 

This species is the type of the subgenus Dallocardia. 

Trachycardiwn procerum (pi. 37, figs. 5-8) is the most 

abundant of the southern species characteristic of the 

Palos Verdes sand. It was found at 20 localities be 

tween localities 112 and 142, inclusive. Arnold re 

corded one specimen from the San Pedro sand of Dead 

man Isla.nd. T. procerum is the type of the subgenus 

Mexicai'dia. 

Trachycardiwn elatum also was found only in the 

Palos Verdes sand. It is rare, however, being repre 

sented by fragments of large valves from localities 112 

and 130. Though this species has subdued ribs, it is 

doubtful whether it is closely related to Laevicardium. 

Trigoniocardia biangulata (pi. 35, figs. 5, 6) is repre 

sented by small and medium-sized specimens from 

deposits on the second terrace at Malaga Cove (locality 

105). This species is assigned to the subgenus Ameri- 

cardia. Heretofore not found'in the Pleistocene of the 

San. Pedro district, it was recorded recently in late 

Pleistocene strata near Playa del Rey. 85 

A small thin-shelled cardiid is identified as Pratulum 

centifilosum. It is abundant in the Lomita marl and 

Timms Point silt (pi. 33, figs. 10, 11) and occurs in the 

San Pedro sand at Deadman Island (locality 30). All 

the specimens except one of those from the San Pedro 

sand are more or less corroded, and many are broken. 

The type material of P. centifilosum from Monterey is 

not in the National Museum. Characters to differ 

entiate P. richardsoni, treated as a variety of P. 

centifilosum by Dall, other than its' larger size are not 

apparent. P. centifilosum ranges from Forrester Island, 

Alaska, to Point Abrecjos, Lower California, The 

fossils are comparable in size to large Alaskan shells 

(length 26.2 millimeters). Specimens from the Cali 

fornia coast are smaller than the fossils, the largest in 

the National Museum (length 19.6 millimeters) being in 

a lot dredged at a depth of 47 fathoms off the Cortez 

Bank. The generic assignment of P. centifilosum is not 

entirely certain, as no specimens of the Australian 

"Cardium" thetidis, the type of Pratulum, 86 are avail 

able. If the Australian "Cardium" pulchellum is a 

typical Pratulum, P. centifilosum is at least subgeneri- 

cally distinct, as "C." pulchellum has minute spines on the 

posterior part of the shell, whereas P. centifilosum has 

concentric lamellae. 

MYACIDAE 

A small elongate form of the circumpolar Mya 

truncata (pi. 33, fig. 12) is one of the northern species 

characteristic of the Timms Point silt. It is rare but 

has been found at localities 44a, 45, and 66 and recorded 

from imit 2 at Timms Point. 87 The fossils are similar 

to Recent shells from Puget Sound, the present southern 

limit of this species on the Pacific coast. A small short 

form of M. truncata occurs in the Pliocene strata at 

Elsmere Canyon. 

PANOPIDAE 

A small form of the circumpolar genus Panomya is 

likewise a northern species characteristic of the Timms 

Point silt. It is identified as a small variety of Panomya 

88 Wlllott, George, op. cit. (San Diego Soc. Nat. History Trans.,' vol. 8, No. 30), 

p. 389, 1937. 

88 Irodalo, Tom, Results from Roy Bell's molluscan collections: Llnnean Soc. New 

South Wales 1'roc., vol. 49, pp. 182, 207, 1924. 

87 Olark, Alox., op. cit. (San Diego Soc. Nat. History Trans., vol. 7, No. 4), table op. 

p. 30, 1931. 


beringianus (pi. 33, figs. 13, 14). The fossils have been 

reported as P. ampla and have been compared with P. 

turgida. 8* P. ampla has a triangular irregular outline, 

whereas P. turgida is more inflated than the fossils and 

has a less conspicuous central groove. The fossils have 

the quadrate outline and conspicuous central groove of 

P. beringianus (type locality, near Pribiloff Islands, 56 

fathoms), which reaches a length of 155 millimeters. 

They are most similar to a pair of small valves (length 

58 millimeters) dredged at a depth of 80 fathoms at 

Port Levasheff, Unalaska. At the present tune Puget 

Sound is the southern limit of the genus, and P. 

beringianus is not recorded south of Bering Sea. Grant 

and Gale figured, however, a similar Puget Sound form 

under the name P. ampla. Panomya occurs in the 

Pliocene (?) Empire formation of Oregon, in Pliocene 

strata near San Francisco and at Los Angeles, and has 

been identified doubtfully in the transition zone be 

tween the Repetto and Pico formations in the Repetto 

Hills on the north border of the Los Angeles Basin. 89 

THRACI1DAE 

The northern Thracia trapezoides occurs in the marl 

facies of the Lomita in San Pedro (localities 37, 41) and 

in the Timms Point silt (pi. 33, fig. 15; localities 32a, 

44, 45). The fossils are cracked or broken. They 

are reasonably similar to the type material of T. 

trapezoides from the Miocene at Astoria, Oreg. (U. S. 

Nat. Mus. 3604) but are considerably larger, and they 

closely resemble Recent shells from San Juan Island, 

Wash. According to the National Museum collection, 

this species now ranges from Sitka, Alaska, to the Santa 

Barbara Islands, but the specimens from the islands 

are small. T. curta, which ranges farther south, is 

smaller and shorter and has a less distinct posterior 

angulation. 

PANDORIDAE 

Pandora grandis (pi. 33, figs. 16-18) is still another 

northern species characteristic of the Timms Point silt. 

It was found at localities 34, 44, and 66. The largest 

fossils are about as large as large Recent Alaskan shells. 

At the present time this species ranges from the 

Pribiloff Islands in Bering Sea to Siletz Bay, Oreg. 

BARNACLES 

Barnacles of the genus Tetraclita, presumably T. 

sguamosa rubescens, are common in collections from the 

rock-cliff and tide-pool facies of terrace deposits older 

than the Palos Verdes sand. Balanus remains, gener 

ally fragmentary, occur locally in terrace deposits and 

other strata. , 

\ 

DECAPOD CRUSTACEANS 

Rathbun 90 described 25 species of decapod Crustacea 

from the Pleistocene of the San Pedro district. Those 

from Oldroyd's Nob Hill locality are from the San 

Pedro sand. Localities and horizons for other forms are 

not specified. Numerous fragmentary remains collected 

during the field work for this report have not been 

identified. 

8' Willett, George, op, cit. (Southern Calif. Acad. Sci. Bull., vol. 36), pp. 61-62,1937. 

" Woodring, W. P., Lower Pliocene mollusks and echinoids from the Los Angeles 

Basin. Calif.: U. S. Qeol. Survey Prof. Paper 190, p. 20, 1938. 

»° Rathbun, M. J., The fossil stalk-eyed Crustacea of the Pacific slope of North 

America: U. S. Nat. Mus. Bull. 138, 155 pp., 1926.

86 GEOLOGY AND JPALEONTOLOGY OF PALOS VERDES HILLS, CALIFORNIA 

BIRDS 

Twenty-one species of birds are recorded by Miller 91 

from the Polos Verdes sand at Arnold's lumber yard 

locality (locality 113), now destroyed. The specimens 

were obtained by sorting great quantities of material. 

The species include the extinct diving goose Chendytes 

lawi, based on material from late Pleistocene terrace 

deposits near Santa Monica. 

A vertebra, determined by Dr. Alexander Wetmore 

of the National Museum as the eighth cervical vertebra 

of an extinct species of vulture of the family Cathartidae 

allied to Coragyps sp., was found at locality 75 in marine 

deposits on the twelfth terrace. 

MARINE MAMMALS 

A broken bone from the algal bed of the Lomita 

marl at Hilltop quarry (locality 53a) is identified by Dr. 

C. L. Gazin, of the National Museum, as the proximal 

end of the third metacarpal of a seal. Seal (Phoca sp.) 92 

and sea lion (Zalophus sp.) 93 remains from the Palos 

Verdes sand at Arnold's lumber yard locality have been 

described by Kellogg. 

LAJSTD MAMMALS 

Blake 94 described and figured a mammoth molar 

from strata representing evidently the Palos Verdes 

sand. Fragmentary vertebrate remains from the 

Palos Verdes sand at Arnold's lumber yard locality were 

listed and discussed by Stock. 95 This material includes 

remains of dire wolf(?), felid, rodents, ground sloths, 

horse, cervids, camelid, and bison. Inasmuch as it-is 

improbable that a considerable population of large 

animals lived on the small island formed by the Palos 

Verdes Hills during Palos Verdes time, most of these 

remains probably represent carcasses that floated out 

from the mainland. 

Dr. Gazin identified a toe bone of a small undeter 

mined mammal, possibly a lagomorph,' in the collec 

tion from the algal bed of the Lomita marl at Hilltop 

quarry (locality 53). He also identified an immature 

femur of a gopher, possibly Thomomys, from deposits 

on the third terrace at locality 91. 

The weighmaster at Sidebotham-No. 1 sand pit, on 

the north border of the hills along Bent Spring Canyon, 

has a considerable cpllection of vertebrate remains 

reported to have been collected from the San Pedro 

sand exposed in the pit. This material includes horse 

teeth arid cervid remains. Vertebrate remains, includ 

ing mammoth and horse teeth, are recorded 98 from the 

"upper beds" (presumably terrace deposits 97) at 

Lomita quarry. Porpoise (Eurhinodelphis) and seal 

(Allodesmus kernensis) remains said to occur with the 

land mammals are doubtless Miocene, as Hay 98 

thought, and according to a communication from Dr. 

' Miller, L. H., Bird remains from the Pleistocene of San Pedro, Calif.: California 

Univ. Dept. Oeol. Bull., vol. 8, pp. 31-38,1914. Further bird remains from the upper 

San Pedro Pleistocene: Condor, vol. 32, pp. 116-118, fig. 45, 1930. Miller, L. H., and 

DeMay, Ida, The fossil birds of California: California Univ., Pub. Zoology, vol. 47, 

No. 4, pp. 57-58,1942. 

" Kellogg, Remington. Pinnipeds from Miocene and Pleistocene deposits of Cali 

fornia: California Univ., Dept. Oeol. Sci., Bull., vol. 13, p. 120,1922. 

83 Kellogg, Remington, Fossil pinnipeds from California: Carnegie Inst. Washing 

ton Pub. 346, pp. 33-35, fig. 7,1927. 

84 Blake, W. P., Geological report [Williamson's reconnaissance in California]: 

U. S. Pacific R. R. Expl., 33d Cong. 2d sess., S. Ex. Doc. 78 and H. Ex. Doc. 91, 

vol. 5, pt. 2, p. 186, 1857. 

95 Stock, Chester, Cenozoic gravigrade edentates of western North America, with 

special reference to the Pleistocene Megalonychinae and.Mylodontidae of Rancho 

La Brea: Carnegie Inst. Washington Pub. 331, pp. 118-119, 1925. 

86 Jordan, D. S., and Hannibal, Harold, Fossil sharks and rays of the Pacific slope 

of North America: Southern California Acad. Sci. Bull., vol. 22, p. 65, pis. 9,10,1923. 

w Idem, p. 63. 

C8 Hay, O. P., The Pleistocene of the western region of North America and its 

vertebrated animals: Carnegie Inst. Washington Pub. 322 B, p. 173, 1927. 

Remington Kellogg are probably from Sharktooth Hill 

in Kern County. 

CALCAREOUS ALGAE 

Calcareous algae are abundant in the Lomita marl 

and make up a large proportion of the algal bed at 

Hilltop quarry. Mesophyllum? is recorded from Lo 

mita quarry. 99 

ENVIRONMENT SUGGESTED BY FOSSILS 

The Pleistocene marine faunas of the San Pedro 

district, with relatively few exceptions, consist of 

species that are still living. They should, therefore, 

yield information that would permit reasonably certain 

conclusions concerning the environment in which they 

lived, provided it be assumed that the species lived in 

the same environment that they now do. In view of 

the relatively short lapse of time involved, this assump 

tion is reasonable and is the basis for the following dis 

cussion, not only for the species that show no change in 

morphological characters available to paleontologists 

but also for species that are not known to be living 

though closely related to living forms. Nevertheless 

it should be realized that the assumption does not take 

into consideration possible changes in physiological 

characters that may not be correlated with changes in 

morphological characters but that may affect distribu 

tion and habits. 1 Furthermore, in a tectonically un 

stable region such as coastal southern California marked 

changes in distribution of land and sea may have taken 

place recently without leaving much clue in the present 

geographic pattern but affecting the distribution of 

marine organisms. 

The following discussion is based almost entirely on 

the mollusks, for they are the most abundant fossils and 

are perhaps better known, than the others. 

The shallow-water mollusks of the Pacific coast of 

North America and their distribution are now fairly 

well known. The fauna at depths of more than 100 

fathoms has been sampled at scattered localities and has 

been described. The fauna at moderate depths, 

especially from 50 to 100 fathoms, is less known than 

either the shallow-water fauna or the deep-water fauna. 

Collections from dredgings. at moderate depths from, 

the islands off southern California and an area off San 

Diego are, however, fairly numerous. Local collectors 

are continually adding material, particularly from 

dredgings in the channel between San Pedro and Cata- 

lina Island. The Albatross occupied well over 100 

stations at depths of 10 to 100 fathoms, mostly 25 to 

100 fathoms, off the islands a'nd off San Diego. The 

mollusks from these dredgings by the Albatross are 

scattered through the systematic west coast collection 

in the National Museum. Dall described some of the 

striking species, but for the most part this material is 

still unidentified. It was used as far as practicable in 

the identification of the Pleistocene mollusks of the San 

Pedro district. If the material were worked up and 

species listed by stations with data covering the depth, 

temperature, and character of bottom, the results 

would go a long way toward filling the gap in the 

knowledge of the moderate-depth fauna of southern 

California. The hauls from depths of about 50 to 75 

fathoms off Point Loma, at the entrance to San Diego 

Bay, are particularly rich and appear to be significant 

89 Howe, M. A., Eocene marine algae (Lithothamnieae) from the Sierra Blanca 

limestone: Oeol. Soc. America Bull., vol. 45, pp. 515, 517, 1934. 

' Woodring, W. P., op. cit. (U. S. Geol. Survey Prof. Paper 190), p. 12,1938.

in interpreting the Pleistocene paleoecology of the San 

Pedro district. 

Numerous local lists of shallow-water mollusks are 

available for localities up and down the Pacific coast. 

They do not help much in paleoecological studies, how 

ever, for most of them, lack other than geographic data. 

During recent years intensive ecological studies have 

boon made at a few localities studies such as those of 

the San Juan Island region, 2 Elkhorn Slough 3 (a marine 

estuary off Monterey Bay), and a rocky coast at Mon- 

toroy Bay. 4 Studies covering different environments at 

numerous localities and at the same localities at different 

times are needed to furnish an adequate basis for paleo 

ecological interpretations. It may be pointed out that 

> Sholforcl, V. 15., and others, Sonic marinebiotic communities of the Pacific coast 

of North America, parti, General survey of thecommunitesiEcologtcalMonographs, 

vol. C, No. 3, pp. 249-332, figs. 1-10,1936. Wlsinor, N. M.. and Swanson, J. H., Some 

marine biotlc communities of the Pacific coast of North America, part 2, A study of 

the animal communities of a restricted area of soft bottom in the San Juan Channel: 

Idem. pp. 333-354 figs. M-15, 1935. 

« Mac Olnltlo, O.K., Ecological arpccts of a California marine estuary: Am. Mid 

land Naturalist, vol. 10, pp. 029-705, 21 figs., 3 maps, 1935. 

« Howatt, W. O.. Ecological suidies on selected marine intertidal communities of 

Montcroy Bay, California: idem, vol. IS, pp. 161-200, 2 pis., 15 figs., 1937. 


ecological investigations that are aimed at recognition 

of a complex classification of animal associations without 

a complete census of the population and without data 

on the habits and life histories of the animals are of little 

value for paleoecological interpretations. 

GEOGRAPHIC DISTRIBUTION OF PLEISTOCENE MOLLUSKS 

THAT ARE STILL LIVING 

Most of the 500 species 01 Pleistocene mollusks are 

still living in the latitude of San Pedro. Early investi 

gators soon realized, however, that some of the species 

are locally extinct in that area, some now living farther 

north and others farther south. The distribution of 

the northern and southern species in the Pleistocene 

strata is shown in the following table, which includes 

Pleistocene forms that are not known to be living but 

that are closely related to living forms. Mollusks that 

have not been identified, notably chitons, epitonids, 

pyramidellids, melanellids, turrids, tectibranchs, and 

leptonacids, are not included in this or other tables. 

Pleistocene mollusks locally extinct in the latitude of San Pedro but now living farther north or south, including forms that are not known to 

be living but that are closely related to living forms 

Gastropods: 

Species 

Northern species 

Triphora fossilis Willott. ............... 

Borcotrophon aft. B. ' multicostatus 

(Eschscholtz). 

Polccypods: 

Chlamys islandicus jordanl (Arnold)... 

Mioclontlscus prolongatus (Carpenter). 

Mncorna calcarca (Omelln), small va- 

rinty. 

Panoinya bnrlngianus Dall, small va 

riety. 

Southern species 

Gastropods: 

Vitrlnclla salvanla (Dall)............... 

Pomaulax turbanlcus potrothauma 

(Berry). 

Mltrafultonl E. A. Smith.............. 

Euploura inuriclforniis (Brodorlp and 

Soworby). 

Acanthlna lugubrls (Sowcrby)......... 

See footnotes at end of table. 

Lower Pleistocene 

Lomita marl 

X 

X 

X 

X 

X 

X X 

X 

X 

a 

2 X 


Pleistocene mollusks locally extinct in the latitude of San Pedro but now living farther north or south, including forms that are not known to 

be living but that are closely related to living forms Continued 

Pelecypods: 

Species 

Southern species Continued 

Muliniapallida(BroderipandSowerby)- 


Lomita marl 

X 

-*^ 

.9 'o 

P4 

CO 

S 

a 

£ 


- 

is y 

12 9 8 

1 Recorded from San Pedro sand by Oldroyd, T. S., U. S. Nat. Mus. Proc., vol. 65, 

art. 22, p. 17, 1924. His specimens, which were not examined, should be compared 

with A. acuteliraia. \ 

2'Willett, George, Southern California Acad. Sci. Bull., vol. 36, p. 62, 1937. 

3 Arnold, Ralph, California Acad. Sci. Mem., vol. 3, p. 317, 1903. 

< Willett, George, op. cit., p. 63. 

'Arnold, Ralph, op. cit., p. 250 ("gradlis"). 

6 Idem, p. 243. ' 

1 

Upper Pleistocene 

Terrace deposits 

6 5 4 

v 

3 2 

X' 

X 

X 

X 

Palos Vp.rdes 

sand 

X 

"X 

10 x 

X 

X 

X 

11 X 

12 X 

X 

X 

7 Idem, p. 246. 

8 Idem, pp. 248-249 (var. pleistocenensis). 

8 Idem, pp. 104-105 ("dmtatus"'). 

10 Idem, p. 108. 

n Idem, pp. 159-160. 

12 Idem, p. 175 ("exoleta"). 

13 Idem, pp. 139-140. 

Present known range 

San Diego (?); San Ignacio Lagoon, Lower 

California, to Costa Rica. 

Closely related to P. cdtaractes, Gulf of Cali 

fornia, and perhaps indistinguishable from 

that form. 

Cedros Island, Lower California, to Ecuador. 

Closely related to 0. megodon proper, Gulf of 

California to Peru. 

A small race or a closely related species San 

Diego (?); Scammon's Lagoon, Lower Cali 

fornia. 

Closely related to C. "varians" from Cape San 

Lucas and La Paz, Lower California. 

San Diego to Panama. 

Magdalena Bay, Lower California, to Panama. 

Magdalona Bay, Lower California, to Ecuador. 

Scammon's Lagoon, Lower California, to Peru. 

Cedros Island, Lower California, to Peru. 

Magdalena Bay, Lower California, to Panama . 

Scammon's Lagoon, Lower California, to Peru. 

Species that are how living at or close to the southern or northern limits of their range in the latitude of 

San Pedro also may be regarded as northern and southern species. They are as follows: 

> 

Pleistocene mollusks now living at or close to southern or northern limits of their range in the latitude of San Pedro or that are related to 

such Recent species 

Gastropods: 

Species 

Northern species 

v> 

Tegula montereyi ("Fischer" Kiener)... 

Tegula marcida (Gould) ["pulligo"]..... 

Calliostoma ligatum (Gould) ["costa- 

tum"]. 

Calliostoma virgineum (Dillwyn) ["an- 

nulatum"]. 

penter) . 

Pelecypods: 

Katherinella subdiaphana (Carpenter). 

Gastropods: 

Southern species 

See footnotes at end of table. 


marl Lomita 

X 

(?) 

i X 

"x" 

X 

v 

'o 

PH 

I 

e 

. £ 

1 X 

(?) 

3 X 

X 

X 

"X 

X 

10 x 

X 

X 

X 

sand San Pedro 

"X 

X 

(?) 

X 

7 X 

"X 

10 x 

X 

X 

12 X 

12 

(?) 

Upper Pleistocene 


9 8 6 5 

X 

X 

4 

' 

X 

X 

3 

X 

2 

X 

X 

Palos Verdes 

sand 

X 

X 

X 


Pleistocene mollusks now living at or close to southern or northern limits of their range in the latitude of San Pedro or that are related to 

such Recent species Continued 

Species 

Southern species Continued 

Gostropods Continued. 

Trltonalla clrcumtoxta aurautia 

(Stoarns). 

Polccypods: 

0 


marl Lomita 

, 

X 

X 

X 

X 

(?) 

X 

X 

4-a 

.3 

o 

OH 

£ 

X 

X 

' X 

(?) 

» X 

X 

X 

X 

sand Pedro San 

13 X 

X 

X 

X 

">X 

16 X 

X 

;« x 

x 

21 X 

X 

v 

x 

12 9 8 6 

i Arnold, llnlph, California Acad. Sci. Mom., vol. 3, p. 341, 1903. Clark, Alex, 

San DICRO Soe. Nat. History Trans., vol. 7, NQ, 4, table op. p. 30, 1931. Willett, 

George, Southern California Aoad. Sci. Bull., vol. 36, p. 04,1937. 

" Arnold, Ralph, op. cit. 

' Arnold, Ralph, op. clt., p. 326. Clark, Alex, op. cit. 

< Arnold, Itulph, op. cit., p. 330. 

8 Clark, Alox. op. cit. ("mamiUaris"). 

o Arnold, Ralph, op. clt., p. 307 ("mamwillaris.") 

' Idem, pp. 286-287. 

8 Idem, p. 228. 

Idem, p. 245. 

10 Idem, p. 241 ("corrugata"). 

" Thoro are no specimens In the National Museum from localities between Cata 

lina Island and Magdalena Bay, Lower California. 

During Pleistocene time the Palos Verdes Hills 

formed an island. That unknown factors correlated 

with a marine insular habitat may affect the distribu 

tion and abundance of some specie's is suggested by the 

occurrence in the Palos Verdes Hills of species that now 

are more abundant along the islands off the southern 

California coast than along the adjoining mainland or 

are unreportcd along the mainland. These species 

include Tegula brunnea, T. montereyi, T. marcida 

["pulligo"], Calliostoma ligatum ["costatum"], C. vir- 

gineum ["annulatum"], Liotia jenestrata, L. acuticostata, 

Amphithalamus indusus, Alvania acutelirala rosana, 

and Jaton gemma. 

DEPTH DISTRIBUTION OF PLEISTOCENE MOLLUSKS THAT 

AJRE STILL LIVING 

Most of the species of mollusks found in the Pleisto 

cene strata are now living in shallov water, less than 10 

Upper Pleistocene v 


X 

X 

X 

5 

X 

X 

4 

X 

v 

X 

(?) 

X 

' X 

X 

3 

X 

X 

2 

X 

X 

X 

X 

X 

X 

Palos Verdes 

1sand 

X 

X 

X 

18 X 

X 

X 

(?) 

20 X 

X 

X 

X 

X 

X 

X 

X 

X 

Present known range 

Catalina Island to San Diego. 

San Pedro to Magdalena Bay, Lower Califor 

nia. 

Probably identical with forms ranging from 

Santa Barbara Islands to Lower California. 

San Pedro to San Bartolome Bay, Lower 

California. 

Closely related to Ft. asperum lomaense, Cata 

lina Island to San Diego, and perhaps indis 

tinguishable from that form. 

Closely related to C. pedroana proper, San 

Pedro to Point Abreojos, Lower California. 

San Pedro to San Diego. 

Closely related to C. gloriosa, San Diego. 

San Pedro to Coronado Islands, near San 

Diego. 

San Diego. 

San Pedro to Lower California. 

Do. 

Santa Barbara Islands to San Diego. 

Newport Bay, Calif., to Lower California and 

Gulf of California. 

" Catalina Island to Panama. ^ 

Catalina Island (?); Lower California to Gulf 

of California. 

Santa Barbara Islands to Scammon's Lagoon, 

Lower California. 

San Pedro to Scammon's Lagoon, Lower Cali 

fornia. 

San Pedro to San Diego. 

San Pedro to Puerto Libertad, Mexico. 

Catalina Island to Gulf of California. 

, Santa Barbara Islands to San Diego. 

San Pedro to. Peru. 

Santa Barbara Islands to San Diego. 

San Pedro to Point Abreojos, Lower California. 

Santa Monica, Calif., to Gulf of Tehuantepec, 

Mexico. 

San Pedro to Panama. 

Do. 

Do. 

» Oldroyd, T. S., U. S. Nat. Mus. Proc., vol. 65, art. 22, p. 21,1924. 


" Idem, p. 291. Clark, Alex, op. cit. 

» Bartsch, Paul, U. S. Nat. Mus. Proc., vol. 40, pp. 331-332, 1911. Oldroyd, T. S. 

op. cit., p. 15. 

18 Bartsch, Paul, op. cit., pp. 345-346. Oldroyd, T. S., op. cit. 

" Willett, George, Southern California Acad. Sci. Bull., vol. 36, p. 62, 1937. 

> 8 Bartsch, Paul, U. S. Nat. Mus. Proc., vol. 33, pp. 250^251, 1907. 

i» Arnold, Ralph, op. cit., p. 289. 

2° Idem, p. 230. 

21 Idem, p. 222 ("varia"). 

fathoms, along the California coast or in water that 

ranges from shallow to a depth of about 25 fathoms. A 

considerable number are known to occur only at moder 

ate depths, 10 to 100 fathoms. None of the species are 

now confined to deep water, more than 100 fathoms, 

but about half of the moderate-depth species range 

into deep water, some to depths as great as 1,000 

fathoms. The species of moderate depth and moderate 

to deep-water depth are listed in the following table, in 

which the known depth range is based for the most part 

on material in the National Museum. The marine 

terrace deposits older than the Palos Verdes sand are 

not included in the table, as those deposits do not con 

tain such species, with the exception of an imperfect 

specimen,. probably Jaton santarosanus, which was 

collected from deposits on the second terrace at locality 

105. That species has a known depth range of 16 to 82 

fathoms.

90 


Pleistocene mollusks now living at moderate depths and at moderate to deep-water depths off the California coast or that are closely related 

to Recent forms having that depth range 

Gastropods: 

Pelecypods: 

Species 

Lomita 

marl 

1 Arnold, Ralph, California Acad. Sci. Mem., vol. 3, p. 341, 1903. Clark, Alex, 

San Diego Soc. Nat. History Trans., vol. 7, No. 4, table op. p. 30, 1931. Willett, 

George, Southern California Acad. Sci. Bull., vol. 36, p. 64,1937. 

2 Arnold, Ralph, op. cit. . ~ 

»Idem. Oldroyd, T. S., U. S. Nat. Mus. Proc., vol. 65, art. 22, p. 21,1924. 

4 Arnold, Ralph, op. cit. 

' Arnold, Ralph, op. cit., pp. 327-328. 

6 Willett, George, op. cit., p. 63, pi. 25. 

7 Arnold, Ralph, op. cit., p. 291. Clark, Alex, op. cit. 

8 Willett, George, op. cit., p. 62. 

The number of species in the preceding table would 

be considerably larger if all the mollusks were identified. 

Turrids of the genera Propebela ["Lora"], "Taranis," 

and Borsonella occur in the Lomita marl and Timms 

Point silt but are rare or absent in the other Pleistocene 

units. At the present time these genera belong to the 

moderate-depth and moderate-depth to deep-water 

groups. 

LOMITA MARL, 

The Lomita marl includes several faunal associations, 

which are interpreted as different depth associations 

ranging from shallow water to about 100 fathoms. 

A shallow-water facies representing a depth of 10 

fathoms or less is identified at locality 61, near Lomita 

quarry. At locality 61 the. fossils occur in gravel and 

coarse-grained calcareous sand, many of the specimens 

being broken and worn. This is the only locality where 

an'oyster, Ostrea megodon cerrosensis, was found in 

the Lomita marl, and none of the species characteristic 

of moderate depths are present. A heavily sculptured 

form of Turritella pedroensis and Olivella biplicata 

are abundant. 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

xxxx 

xxxxxxxxxxx 

X 

X 


Timms 

Point 

silt 

XXXXXXXX 

xxxxxxxxxxx xxxxx 

X 

X 

. X 

X 

X 

xxxxxxx 

San 

Pedro 

sand 

XXXXX 

6 X 

X 

X 

X 

xxxxxxxx 

X 

X 

X' 

X 

17 x 

X 

X 

X 

X 

X 

Upper 

Pleisto 

cene, 

Pales 

Verdes 

sand 

4 X 

X . 

X 

X 

X 

10 x 

X 

"X 

X 

8 

X 

1 

Present known depth range off 

.California coast (fathoms) 

30-67. 

48. . 

34-110. 

16-95. 

Probably identical with P. caryophylla, 67-81. 

53-822. 

20. 

32-239. 

81. 

South of Puget Sound range of genus is 68-243. 

67-71. 

30-53. 

Probably identical with forms ranging from 50-181. 

Closely related to B. asperum lomaense and perhaps indis 

tinguishable from that form, which ranges from 20-71. 

50-155. 

48-795. 

32-60. 

80-1,081. 

30-218. 

68-211. 

80-389. 

71-376. 

Related evidently to B. pacificus; 67-92. 

50-202. 

Probably identical with A. rhyssa, 53-81. 

48-110. 

55-1, 090. 

16-233. 

25-200. 

30-80. 

Closely related to P. stearnsii diegensis, 14-266. 

21-110. 

Related to P. bistriatus, 822. 

40-200. 

20. 

45-48. 

25-110. 

62-276. 

Related evidently to C. pacifica. 30-506. 

16-167. 

30. 

Apparently identical with a small race, 13-51. 

13-270. 

16-108. 

16-51. 

Arnold, Ralph, op. cit., pp.-286-287. 

10 Idem, pp. 224-225. 

» Idem, p. 228. 

13 Idem, p. 253 ("tenuisculptus"). 

18 Idem, p. 252 ("scalariformis")., Clark, Alex, op. cit. 

14 Arnold, Ralph, op. cit., p. 251 '("multicostatus"), p. 252 ("scalariformis"). 

» Idem, pp. 252-253. Clark, Alex, op. cit. 

16 Arnold, Ralph, op. cit., pp. 252-253. 

i' Arnold, Ralph, U. S. Geol. Survey Prof. Paper 47, pp. 126-127, 1906 ("riversi"). 

is Crickmay, C. H., Canadian Field Naturalist, vol. 43, No. 5, p. 93, 1 fig., 1929. 

The algal bed at Hilltop quarry is thought to repre 

sent a depth of between 25 and 50 fathoms. The 

following species are particularly abundant in that bed: 

Most abundant mollusks in algal bed of Lomita marl at 

Hilltop quarry (localities 53, 5Sa) 

Gastropods:_ ( 

Pupillaria optabilis (Carpenter). 

Pomaulax undosus (Wood). 

Pachypoma gibberosum (Dillwyn). 

Hornalopoma carpenter! (Pilsbry). 

Bittium rugatum Carpenter. 

Bittium attenuatum Carpenter. 

Bittium asperum (Gabb). 

Bursa californica (Hinds). 

Kelletia kelletii (Forbes). 

Mitrella tuberosa (Carpenter). 

Amphissa versicolor Dall. 

Conus californicus Hinds. 

Pelecypods: 

Glycymeris profunda (Dall). 

Cyclocardia aff. C. occidentals (Conrad). 

Ventricola fordii (Yates).

There are no shallow-water Littorinas, Anomias, 

mussels, Aequipectens, oysters, or large chamids in 

the algal bed, but the following moderate-depth species 

are present: 

Moderate-depth species in algal bed of Lomita marl at Hilltop 

quarry (localities 58, 5Sa) 

Gastropods: 

Acmaea funiculata (Carpenter)? 

Puncturella delosi Arnold. 

Solariclla rhyssa Dall. 

Homalopoma subobsoletum (Willett). 

Alvania acutelirata rosana Bartsch. 

Bittium rugatum Carpenter. 

Bittum asperum (Gabb). 

Fusitriton oregonensis (Redfield). 

Neptunea tabulata (Baird). 

Admete gracilior (Carpenter). 

Pelecypods: 

Pectcn stearnsii Dall. 

Kucrassatella fluctuata (Carpenter). 

Cyclocardia aft. C. occidentalis (Conrad). 

The algal bed represents evidently an exceptional 

environment. Though calcareous algae are abundant 

in some layers of the Lomita elsewhere, they do not 

elsewhere play such an overwhelming part among the 

.constituents. Seven species of mollusks, notably 

Pomaulax turbanicus petrothauma and Tritonalia cory- 

phaena, were not found elsewhere. 

The calcareous sand and gravel at locality 54g, con 

stituting unit 7 of the section in the canyon adjoining 

Hilltop quarry, is thought to represent the same depth 

range as the algal bed. For unknown reasons calcareous 

algae are much less abundant than in the algal bed. 

The fossils in calcareous sand and marl at other locali 

ties indicate essentially the same depth range, between 

25 and 50 fathoms. All the Lomita moderate-depth 

species are present in those strata, with the exception 

of Pseudamussium, Hyalopecten, Propeamussium, and 

Thracia trapezoides. In some layers of both calcareous 

sand and marl, such as the calcareous sand at locality 

42d, only small and minute shells, particularly herbi 

vorous gastropods, and young shells are present, 

suggesting current sorting. The most perfectly pre 

served fossils were collected from the dump of the 

central shaft of the Whites Point tunnel (locality 57). 

Bittium rugatum, Turritella pedroensis, "Nassa" mendica 

cooperi, Olivella biplicata, Conus californicus, and 

Cyclocardia aff. C. occidentalis are abundant at locality 

57. Three species of Boreotrophon are present. 

The glauconitic foraminiferal sand and foramim'feral 

calcareous sand in the lower part of the section exposed 

in the canyon adjoining Hilltop quarry and forming the 

exposed section at Lomita quarry are thought to repre 

sent a greater depth, between 50 and 100 fathoms. 

Cyclocardia barbarensis is generally abundant in those 

strata (localities 54, 54a, 54c,. 54e, 54f, 62b). Cyclo 

cardia off C. occidentalis occurs, however, in some layers 

(localities 54a, 54c). In the dark-colored glauconitic 

sand at Lomita quarry (locality 62b) Cyclocardia 

barbarensis is the only abundant mollusk, and it is 

associated with Pseudamussium n. sp., Hyalopecten 

vancouverensis, and Propeamussium alaskensis, an asso 

ciation suggesting a depth of about 100 fathoms. The 

marl in San Pedro containing Thracia trapezoides 

(localities 37, 41) also represents probably a depth 

greater than 50 fathoms. 

Wherever more than one inferred depth facies is 

represented in the same section, the deeper facies 

underlies the more shallow facies. This relation is well 

shown in the section exposed in the canyon near Hilltop 

602787 ,45 7 


quarry, where Cyclocardia barbarensis-bQ&rmg glau 

conitic foraminiferal sand and foraminiferal calcareous 

sand thought to represent a depth of between 50 and 

100 fathoms, is overlain by calcareous sand and gravel 

characterized by fossils whose depth range is inferred 

to be between 25 and 50 fathoms. The large-cobble 

calcareous gravel at the top of the section represents 

doubtless a shallow facies, but no fossils were found in 

it. The shallow-water gravel and calcareous sand at 

locality 61 is younger evidently than the 50-fathom to 

100-fathom facies at Lomita quarry; intervening strata 

are not exposed. 

As shown in the tables on pages 87-89, the Lomita 

marl contains 12 identified northern species, 6 of which 

are locally extinct, but are living farther north. The 

northern Fusitriton oregonensis, Chlamys islandicus 

jordani, Patinopecten caurinus, Thracia trapezoides, 

and the essentially northern Neptunea tabulata all of 

which occur in the Lomita marl have been considered 

characteristic of the Timms Point silt. On the con 

trary the Lomita contains 20 identified southern species. 

Of the southern species still living only one, Macron 

aethiops, is more than 100 miles north of its present 

range. Pomaulax turbanicus petrothauma and Ostrea 

megodon cerrosensis, which are not known to be living, 

are closely related to species living hundreds of miles 

farther south. An early statement 8 that the Lomita 

marl includes a fauna of warmer facies than the fauna 

of the Palos Verdes sand is now considered erroneous. 

The temperature of the water was probably essentially 

the same as at the present time in this region. Inas 

much as the sediments were deposited on the leeward 

side of an island, the temperature of the shallower 

water between the island and the mainland may have 

been higher than at the present time, owing to protec 

tion from upwelling cold water. It is not known, 

however, whether the leeward side of Catalina and 

other nearby islands is so protected. Gale 6 assigned 

the Lomita marl to the first interglacial stage. This 

matter is considered under the heading "Glacial-inter- 

glacial assignments," page 100. 

The Lomita sediments at most localities indicate 

clear water. An environment evidently comparable to 

that of parts of the Lomita has been found on the lee 

ward side of Catalina Island, where calcareous sedi 

ments are accumulating on a shelf at a depth of about 

40 to 50 fathoms. 7 A sample of the calcareous sedi 

ments from a depth of 45 fathoms off Avalon is avail 

able through the kindess of Professor Shepard. The 

proportion of detrital nonorganic material, estimated to 

be 25 percent, is larger than in much of the Lomita. 

The principal organic constituents in approximate 

order of decreasing abundance are as follows: Foramini- 

fera, calcareous algae, mollusks, echinoid spines, Bryo- 

zoa. Mollusks are represented by about 50 species. 

With few exceptions, notably some valves of Cyrilla 

munita, the specimens are bleached, worn, and broken. 

As hi much of the Lomita, the specimens are small, con 

sisting of adult small shells and young shells or small 

fragments of larger species. Species of considerable size, 

such as "Nassa" mendica cooperi?, Glycymeris sp., 

Eucrassatella fluctuata?, and Pratulum centifilosum?, 

are represented, but the specimens are minute young 

shells or fragments not more than a few millimeters 

* \Voodring, W. P., Warm-water faunas of the so-called Pliocene of San Pedro (ab 

stract): Geol. Soc. America Bull., vol. 41, pp. 211-212,1930. 

6 Grant, U. S., IV, and Gale, H. R., op. cit. (San Diego Soc. Nat. History Mem., 

vol. 1), p. 71,1931. 

: Shepard, F. P., and Wrath, W. F., Marine sediments around Catalina Island: 

Jour. Sedimentary Petrology, vol. 7, pp. 45, 48, 1937.


long. The faunal association resembles that of much 

of the moderate-depth facies of the Lomita. Boreo- 

trophon, Admete, Thyasira, and Axinopsis, which are 

abundant generally in that facies of the Lomita, are, 

however, not represented. 

Along the north border of the Palos Verdes Hills, 

west of the Gaffey anticline, the Lomita calcareous 

sediments contain a considerable amount of silty sand 

and sand. The fauna is, however, essentially the same 

as in purer calcareous sand farther east. 

TIMMS POINT SILT 

The Timms Point silt contains several faunal asso 

ciations that are not strikingly different. They are 

inferred to represent a moderate-depth range of between 

50 and 100 fathoms. . 

At Timms Point pockets of calcareous silt at the base 

of the formation contain a fauna of small and young 

shells indistinguishable from that in calcareous sand 

of the Lomita marl. This material may .represent 

detrital constituents from the Lomita marl, but the 

fossils are as fresh as those in the undisturbed Lomita 

marl. It represents more probably a nondetrital facies 

during the early stage of the marine transgression. The 

size sorting of the fossils suggests current sorting. 

The remainder of the section at Timms Point contains 

a fauna characterized by the abundance of the moderate- 

depth and northern species listed on pages 87-89. This 

association is thought to represent a depth close to 100 

fathoms, a conclusion reached by Bagg 8 from a study 

of the Foraminifera. The northern Thyasira disjuncta 

and Mya truncata have been found in unit 2 but not in 

unit 1. The slight faunal distinction between units 1 

and 2 is probably of doubtful value, for Trachycardium 

guadragenarium, formerly thought to be characteristic 

of unit 1, and Pandora grandis, thought to be charac 

teristic of unit 2, occur together at locality 34 on Harbor 

Boulevard. The stratigraphic relations at locality 34 

are uncertain, but the strata represent probably unit 2. 

On Deadman Island Crickmay 9 found Thyasira .dis 

juncta only in his zone 5, which is therefore faunally 

similar to unit 2 so far as the occurrence of that species 

is concerned. The occurrence of Pandora grandis at 

locality 44 on Second Street likewise suggests unit 2. 

The Timms Point silt is identified doubtfully on 

lithologic grounds at locality 52, immediately west of 

Gaffey Street. The few fossils collected are inconclu 

sive, however, as they might represent the Lomita, 

Timms Point, or San Pedro. A Timms Point fauna at 

locality 66, on the north border of the hills near Agua 

Magna Canyon, suggests unit 2 at Timms Point, as it 

includes Mya truncata and Pandora grandis. 

A marked feature of the Timms Point fossils is the 

prevalence of moderate-depth species, most of which 

occur also in the Lomita marl, and the scarcity or 

absence of shallow-water species. The only oyster is 

a minute shell from locality 66. There are no Anomias, 

mussels, or large chamids. The specimens of Olivella 

biplicata, though locally abundant, are worn and 

broken, and the few specimens of Conns californianus 

are likewise worn and broken, suggesting transportation 

from an area of shallow water. 

Owing to the relatively large .number of northern 

species, the northern aspect of the Timms Point fossils 

8 Bagg, R. M., Jr., Pliocene and Pleistocene Foraminifera from southern California: 

U. S. Oeol. Survey Bull. 513, p. 13,1912. 

' Crickmay, C. H., The anomalous stratigraphy of Deadman's Island: Jour. 

Geology, vol. 37, pp. 626-627. 1929. 

has been emphasized repeatedly. Arnold 10 considered 

the fauna boreal, Smith u thought the temperature of 

the water was about the same as that of Puget Sound, 

and Gale 12 assigned the Timms Point silt to the second 

glacial stage. This matter is considered under the 

heading "Glacial-interglacial assignments," page 100. 

The Timms Point silt is inferred to represent the 

same depth range as the lower part of the Lomita marl. 

Whether the difference hi faunal associations may be 

accounted for by the clearer water indietaed by the 

Lomita is not known. All except one of the locally 

extinct northern species that give the Timms Point 

fauna its individuality are pelecypods, the presence or 

absence of which may be controlled by the character 

of the bottom. 

SAN PEDRO SAND 

The San Pedro sand contains several well-marked 

faunal associations, which like the associations in the 

Lomita marl are attributed to different depth facies. 

A shallow-water facies is recognized along and near 

Harbor Boulevard at localities 49, 49a, and 50. At 

these localities the fossils include Cerithidea californica, 

.Macron aethiops kellettii,."Cancellaria" tritonidea, Ter- 

ebra pedroana, Melampus olivaceus, Anomia peruviana, 

Ostrea lurida, and large sand dollars, most of which were 

not found in the San Pedro sand in San Pedro. A shal 

low-water Anomia-Ostrea facies, characterized by the 

abundance of Anomia peruviana and Ostrea lurida, is 

represented on the south limb of the Gaffey syncline at. 

localities 58a and 59 and in less characteristic form at 

locality 56. Tegula ligulata was found in the San Pedro 

sand only at localities 58a and 59. All the shallow- 

water species mentioned and the other species repre 

sented at those localities occur also in the younger Palos 

Verdes sand. In fact, this Palos Verdes-like shallow-water 

facies of the San Pedro sand is so similar to the usual 

Palos Verdes facies that there is some doubt about the 

age assignment, the stratigraphic evidence being incon 

clusive. At localities 49 and 58a, however, fossiliferous 

sand and gravel containing southern species character 

istic of the Palos Verdes overlie the strata identified as 

the San Pedro sand. The Palos Verdes-like facies rep 

resents evidently protected shallow water lying in the 

lee of the growing Gaffey anticline. It includes, like 

the usual Palos Verdes facies, tide-flat species Ceri 

thidea californica and Melampus olivaceus. 

Localities 47 and 47a in San Pedro and Oldroyd's 

nearby Nob Hill locality 13 are triought to represent 

shallow water. The water was deeper, however, than 

at the localities just described, or species from depths 

greater than 10 fathoms were washed in by storm waves, 

as Oldroyd 14 inferred. Whether the fresh-water Hy- 

drobia protea from locality 47a and the fresh-water 

pulmonates recorded by Arnold lived in streams on the 

Pleistocene Palos Verdes Hills island or were derived 

from the mainland is not known. If they lived on the 

island, the climate was more humid than at present. 

At localities 30 on Deadman Island, 48 in north 

western San Pedro, 58 on Western Avenue, and 64 

and 65 on the north border of the hills along Bent Spring 

Canyon, the San Pedro sand includes moderate-depth 

species not found elsewhere in that unit. Those 

1° Arnold, Ralph, The paleontology and stratigraphy of the marine Pliocene and 

Pleistocene of San Pedro, Calif.: California Acad. Sci. Mem., vol. 3, p. 16, 1903. 

" Smith, J. P., Climatic relations of the Tertiary and Quaternary faunas of the 

California region: California Acad. Sci. Proc., 4th ser., vol. 9, p. 151, 1919. 

12 Grant, U. S., IV, and Gale, H. R., op. cit., p. 71. 

is Oldroyd, T. S., The fossils of the lower San Pedro fauna of the Nob Hill cut, 

San Pedro, Calif.: U. S. Nat. Mus. Proc., vol. 65, art. 22, 39 pp., 2 pis., 1924. 

" Idem, p. l.

localities therefore are inferred to represent a moderate 

depth, probably between 25 and 50 fathoms. These 

species are as follows: 

Moderate-depth species found in San Pedro sand at localities SO, 

48, GS, 64, and 66 but not elsewhere in that unit 

Gastropods: 

Puncturolla cooped Carpenter __ ... __ ... 

Turoica caffoa (Gabb)......................... 

Klassurn californictim (Dall and Bartsch) ».-.. 

Noptunoa tabulata (Baird).. _ .......... _ . 

Polccypods: 

Nucula all. N. cardara Dall. __ . ___ ........ 

Eucrassatolla fluctuata Carpenter __ ... __ . 

Thyasira gouldil (Plilllppl).... ................ 

Axlnopsis vlrldls Dall.. . __ . __ ..... _ . 

30 

X 

1 X 

X 

X 

X 

X 

X 

X 

X 

48 

X 

X 

I 

jocalit 1? 

' Arnold, Ralph. California Acad. Scl. Mom., vol. 3, pp. 327-328, 1903. 

8 Not known to bo living. Associated with intermediate-depth species in Lomita 

marl and Timms Point silt. 

8 A northern species associated with intermediate-depth species in Lomita marl 

and Timms Point silt. 

At locality 64 the fossils occur in silty sand contain 

ing lenses of coarse sand and gravel resting on Miocene 

strata on the north flank of the Gaffey anticline. At 

locality 65 nearby they occur in marly silty sand over 

lying about 100 feet of coarse sand and gravel. At 

both localities the faunal association closely resembles 

that in the Lomita marl at numerous places. The 

strata at locality 64 are in the stratigraphic position 

of the Lomita marl and Timms Point silt; those at 

locality 65 are at the exposed top of the San Pedro 

58 

X 


64 

X 

X 

65 

y 

sand. The sand containing moderate-depth species at 

locality 58 underlies the shallow-water Anomia-Ostrea 

facies of locality 58a. The fossils from locality 73a, 

in the fifth ravine west of Hawthorne Avenue, represent 

apparently shallower water than those just described. 

The San Pedro sand contains 6 locally extinct north 

ern species but no locally extinct southern species far 

north of its present range, with the exception of Arnold's, 

record of Trachycardium procerum, which may perhaps 

be questioned. It contains both northern and south 

ern species now at or close to the limits of their range 

in the latitude of San Pedro. Arnold 15 considered the 

fauna of the San Pedro sand to be transitional cool- 

water; Smith 16 considered it cool-water and thought.it 

corresponded to the time of maximum glaciation; Gale 17 

assigned it to the second interglacial period. This 

matter is discussed under the heading "Glacial-inter- 

glacial assignments," page 100. 

MARINE TERRACE DEPOSITS OLDER THAN PALOS VERDES 

SAND 

Fossils have been found in marine deposits on 8 of 

the 12 main terraces older than the first or lowest ter 

race. With the exception of a few localities, the fossils 

represent a more uniform facies than those already 

described. The usual facies and the only facies now 

known from the twelfth to fifth terrace, inclusive, con 

sists of species that live on rocks and in tide pools but 

includes species living below low-tide line. This facies 

has been designated a tide-pool facies. 18 It is more 

appropriate, however, to designate it a facies that rep 

resents both rock-cliff and tide-pool environments. 

The most abundant species in this facies and their 

present habitat are as follows: 


16 Smith, J. P., op. cit., pp. 136-137. 

" Grant, U. S., IV, and Gale, H. B., op. cit. (San Diego Soc. Nat. History Mem., 

vol. 1), p. 71, 1931. 

18 Woodring, W. P., Fossils from the marine Pleistocene terraces of the San Pedro 

Hills, Calif.: Am. Jour. Sci., 5th ser., vol. 29, p. 297,1935. 

Most abundant species in rock-cliff and tide-pool facies of marine terrace deposits older than Palos Verdes sand and their present habitat 

Gastropods: 

Acnuica limatula Carpenter. 

Acmaea scabra (Could).... 

Acrmiea asmi (Middendorff). 

Haliotis cracherodii Leach.. 

Fissurella volcano Reeve.____________ 

Tegula funebralis (Adams)______._-_- 

Tegula gallina (Forbes)______________ 

Pseudorotella invallata (Carpenter).... 

Pseudorotella supravallata (Carpenter). 

Homalopoma carpenter! (Pilsbry) _ _ _ _ . 

Homalopoma bacula (Carpenter) ___... 

Littorina planaxis Philippi, small form. 

Littorina scutulata Gould.___________ 

Barleeia haliotiphila Carpenter._______ 

Truncatella stimpsoni Stearns.--..---- 

Truncatella californica Pfeiffer._______ 

Syncera translucens (Carpenter). .__ 

Spiroglyphus lituella (M6rch)_________ 

Hipponix antiquatus (Linne)________ 

Hipponix tumens Carpenter._________ 

Oadinia reticulata (Sowerby)__.-.____ 

Pelecypods: 

Septifer bifurcatus (Conrad)...._-____ 

Glans subquadrata (Carpenter) _______ 

Epilucina californica (Conrad)________ 

Species Present habitat 

Rock, intertidal. . 

Rock, from upper edge of spray to low-tide line. 

On Tegula. 

In crevices and under rocks, intertidal and below low-tide 

line. 

Rock, intertidal. 

Rock, intertidal and tide pools. 

Rock, at high-tide line and intertidal. 

; 

Tide pool, under loose rocks and among eel grass roots. 

Tide pool, under loose rocks. 

Rock, in spray zone. 

Rock; intertidal. 

In "moss" on abalones. 

"Under loose rocks near high-tide line. 

In vegetation just above high-tide line. 

Rocks, interdial. 

Tide pool, in rock crevices. 

Rock, in crevices, intertidal. 

Tide pool, in rock crevices and under loose rocks. 

Attached to under side of rocks, intertidal. 

Tide pool, in sand between rocks.

94 GEOLOGY AND PALEONTOLOGY OF PALOS VEKDEg HILLS, CALIFORNIA 

Gastropods greatly outnumber pelecypods in the 

rock-cliff and tide-pool facies, the average ratio of 

pelecypod species to gastropod species in 28 collections 

being 1 : 5.2. In no collection are there more than 7 

species of pelecypods. 

The fossils from the twelfth terrace at an altitude of 

1,215 feet above sea level are representative of the 

rock-cliff and tide-pool facies. This collection is: of 

exceptional interest, as it represents the greatest alti 

tude at which Pleistocene marine terrace fossils have 

been found along the California coast. The species are 

a,s follows: 

Fossils from marine deposits on twelfth terrace, altitude 1,215 feet above sea level (locality 75) 

'Gastropods: 

Acmaea limatula Carpenter______________________ 

Acmaea scabra (Gould)_________________________ 

Acmaea pelta "Eschscholtz" Rathke__L___________ 

Acmaea insessa Hinds?_____-_---_____---______. 

Haliotis cracherodii Leach.______________________ 

Fisurella volcano Reeve_________________________ 

Lucapinella callomarginata ("Carpenter" Dall)?____ 

Diodora aspera ("Eschscholtz" Rathke)___________ 

Norrisia norrisi (Sowerby)_______________________ 

Tegula gallina (Forbes)_-__-_____-____--_______. 

'Tegula brunnea (Philippi)?______-_.___--________ 

Pupillaria succincta (Carpenter)__________________ 

Pomaulax undosus (Wood)?_________. ___________ 

Homalopoma carpenter! (Pilsbry)__---__-_______. 

Homalopoma bacula (Carpenter)__________________ 

Homalopoma paucicostatum fenestratum (Bartscli). 

Littorina planaxis Philippi, small form____________ 

Littorina scutulata Gould-______________________ 

Bittium armillatum Carpenter___________________ 

Bittium interfossa (Carpenter)______________ ___. 

Cerithiopsis williamsoni (Arnold)__________________ 

Seila montereyensis Bartsch_____________________ 

'Triphora pedroana Bartsch_ _____________________ 

Aletes squamigerus Carpenter.__--__-_---________ 

Hipponix antiquatus (Linne)___-----___--________ 

Hipppnix tumens Carpenter.______________________ 

Crepidula aculeata (Gmelin) __ ___---_--_____^-___ 

Crepipatella lingulata (Gould)__..-__-__--________ 

Harfordia monksae (Dall)?______..______-________ 

"Fusinus" luteopictus Dall?_ _^-__-______________ 

Mitra idae Melvill___-___-____--_--_-----__-_-_- 

"Nassa" mendica cooperi Forbes_________________ 

Tritonalia interf ossa (Carpenter) _________________ 

Tritonalia gracillima (Stearns)?___-__-___________ 

Amphissa versicolor Dall____ ______________ ______ 

Olivella biplicata (Sowerby)______________________ 

Pseudomelatoma torosa (Carpenter)?_____________ 

Mangelia cf. M. rhyssa (Dall)_ ________________ 

Mitromorpha filosa (Carpenter)__________________ 

Mitromorpha gracilior ("Hemphill" Tryon)________ 

Mitromorpha aspera (Carpenter)_________________ 

Conus californicus Hinds.____________ __________. 

Gadinia reticulata (Sowerby)_____________________ 

Pelecypods: 

Septifer bifurcatus (Conrad)____..----_--________. 

Glans subquadrata (Carpenter) _______________ 

Epilucina californica (Conrad) ________________ 

Species Abundance and condition 

The fossils recorded by the Chaces 19 from deposits on 

the second terrace near Point Fermin (locality 94) also 

represent the rock-cliff and tide-pool facies. The 

abundance of chitons is, however, exceptional. 

Most of the species that are now abundant along 

rocky stretches of the coast of the Palos Verdes Hills are 

present in the rock-cliff and tide-pool facies. Acmaea 

digitalis and Mytilus adamsianus are notable exceptions, 

and Mytilus californicus is rare among the fossils. On 

the contrary, the fossils include shallow-water species 

that live below low-tide line, species that live at moder 

ate depths in the latitude of San Pedro (Acmaea mitra, 

Diodora ,aspera), species that are almost extinct locally 

though abundant a little farther north (Tegula June-, 

bralis), northern and southern species that are clos.e to 

" Chacc, E. P., and E. M., An unreported exposure of the San Pedro Pleistocene: 

Lorquinia, vol. 2, No. 6, pp. 41-43.1919. 

Common, worn. 

Abundant, well-preserved. 

Common, worn- 

Rare, I worn small. 

Common, 1 well-preserved, others worn fragments. 


Rare, 1 small fragment. 

Rare, 1 worn. 

Common, small, broken. 

Abundant, apex generally broken. 

Rare, 1 worn, broken. 

Rare, well-preserved. 

Rare, columellar fragments. 

Common, broken and fragments. 

Rare, 1 wellrpreserved, 2 broken. 

Common, broken. 

Abundant, mostly somewhat worn. 

Abundant, some' welll-preserved, others broken. 

Common, worn or broken. 

Common, 1 well-preserved, others broken. 

^Rare, broken or worn. 

'Common, broken1 and worn. 

Common, broken and somewhat worn. 

Abundant, pieces. 

Abundant, mostly well-preserved. 

Abundant, mostly welflr-preserred. 

Rare, worn. 

Rare, worn. 

Rare, 1 worn fragment. 

Rare, 1 well-preserved!, very small. 

Rare, 1 broken and worn. 

Rare, 1 small, broken, worn). 

Common, small, broken.. 

Rare, 2 apertural fragments. 

Common, broken and: worn. 

Abundant, broken or worn, or both. 

Rare, 2 small, broken, worm. 

Rare, 2 somewhat worn. 

Rare, 1 worn. 

Rare, 1 broken, worn. 

Rare, 2 well-preserved,, 1 broken, worn. 

Abundant, worn, or worn and broken." 

Rare, somewhat worn. 


Common, well-preserved, or somewhat worn. 

Common, well-preserved, or somewhat worn and broken. 

the present limits of their range, a locally extinct 

northern species, and a locally extinct southern species. 

Two localities are notable exceptions to the prevailing 

terrace facies. At Bluff Cove, 69 species of gastropods 

and 19 of pelecypods were collected from deposits on the 

fourth terrace (locality 86). In addition to expectable 

terrace species this collection includes Terebra pedroana, 

Bulla gouldiana, Haminoea, Crassinella branneri, 

Lucinisca nuttallii, Macoma nasuta, Macoma secta, 

arid Cryptomya californica, all of which are well-pre 

served. These sp ecies indicate protected shallow wate r. 

The faunal association is. therefore a mixture of rocl.T 

cliff, tide-pool, and protected shallow-water facies. 

The protected shallow-water species were transported 

presumably from a locality nearby. A similar mixed 

faunal association was found on the second terrace in the 

Malaga Cove residential district (locality 105). At that

locality 70 species of gastropods and 39 of pelecypods 

were collected from coarse sand trapped in a niche and 

sealed, by boulders. The fossils include Rissoina 

kelseyi, R. pleistocene,, Crucibulum spinosum, Trivia 

solandri, Mitra, fultoni, Jaton santarosanus?, Nucula 

suprastriata, Sacella taphria, Yoldia, Glycymeris cor- 

teziana, Anomia peruviana, Botulina "opifex", Crenella, 

Pecten vogdesi, Ostrea lurida, Crassinella nuculiformis, 

Diplodonta sericata,, Semele decisa, Chione succincta, 

and Trigoniocardia biangulata, in addition to usual 

terrace species. Most of the exceptional species indi 

cate protected shallow water, but a few suggest water 

of moderate depth. At Hilltop quarry (locality 93) a 

few poorly preserved fossils collected from deposits on a 

terrace identified as the third, but possibly representing 

the second, include Turritella pedroensis, Bursa cali 

fornica?, and " Cancellaria" tritonidea?. This is the 

only locality where those species were found in terrace 

deposits older than the Palos Verdes sand. All the 

specimens are broken and battered and may be detrital. 

The distribution of northern and southern terrace 

species is shown in the tables on pages 87-89. The one 

northern species now locally extinct is from the rock- 

clift' and tide-pool facies of the fourth and second 

terraces. The eight southern locally extinct species 

are, from the fourth and second terraces and with two 

exceptions arc from the unusual localities 86 and 105 

just described. The exceptions are Acanthina lugubris 

from rock-cliff and tide-pool facies on the fourth terrace 

at localities 82, 84, and 85, and from the same facies on 

the second terrace at localities 94 and 106, and " Chione" 

picta reported orally by Chace from a protected shallow- 

water facios on the second terrace at Fifteenth Street 

near Leland. Northern species at or close to the 

southern limit of their present range were found on the 

fifth to second terraces, inclusive, and similar southern 

species on the sixth to second, inclusive. Owing to the 

presence of several chitons now rare as far south as 

San Pedro, Berry 20 thought that the deposits on the 

second terrace near Point Fermin are to be correlated 

with the San Pedro sand. This matter is discussed 

under the heading " Glacial-interglacial assignments," 

page 100. 

PALOS VER»ES SAND 

The 38 fossil localities representing the Palos Verdes 

sand, the marine deposits on the first or youngest 

terrace, are on the leeward (east and northeast) side of 

the hills. The prevailing faunal association, and the 

only association from localities 110, 111, and 112 nor-th- 

ward and northwestward to locality 142, consists prin 

cipally of species that indicate protected shallow water. 

Locally extinct southern species, notably CTassinella 

branneri, Crassinella nuculiformis, and Trachycardium 

procerum, are characteristic of this facies. During 

ralos Verdes time shallow-water bays evidently ex 

tended into the island formed by the Palos Verdes Hills 

from the strait separating the island from the mainland. 

Tide-flat species, Cerithidea californica and Melampus 

olivaceus, occur at numerous localities. Most of the 

material is not in place and represents current-strewn 

debris. It is generally necessary to sort great quanti 

ties of broken shells and fragments to find well-preserved 

shells. Macoma and Macoma-"Paphia" layers at locali 

ties 113 and 114 and nearby in northeastern San Pedro 

represent protected shallow-water species that are essen- 

80 Berry, S. S., Fossil chitons of western North America: California Acad. Sci. Proc. 

4th ser., vol. 11, pp. 408-409,1922. 


tially in place. Rock-cliff and tide-pool species are 

generally rare, though most of the species in that facies 

on the older terraces occur also in the Palps Verdes sand. 

Their scarcity in the Palos Verdes sand is attributed to 

the prevalence of soft Miocene and Pleistocene rocks 

along much of the Palos Verdes coast on the leeward 

side of the hills. Fresh-water snails Valvata humeralis 

californica, Amnicola longingua, Hydrobia protea, and 

pulmonates of the genera Helisoma, (jyraulus, and 

Physa are rare constituents. If these snails lived in 

streams on the island, the climate was more humid than 

at present. 

The mixed faunal association at Arnold's lumber 

yard locality (locality 113)., more thoroughly explored 

than any other Palos Verdes locality, has been discussed 

by Miller. 21 Marine mollusks, mostly broken shells in 

a matrix of coarse-grained sand and gravel, form the 

bulk of the fossil material. Remains of sting rays are 

fairly common. Fossil shore and ocean birds (loon, 

grebe, albatross, shearwater, fulmar, cormorant, goose, 

mallard, teal, surf scooter, diving goose, gull, and 

murrelet) and mammals (seal, sea lion, and whale), all 

represented by rare fragmentary remains, are'expect 

able in marine strata. Fresh-water mollusks and mud 

turtle are fresh-water constituents. Land animals are 

represented by rare fragmentary remains of birds 

(vulture, eagle, quail, and meadowlark) and mammals 

(canid, felid, rodent, ground sloth, horse, cervid, came- 

lid, bison, and mammoth). It is inferred that this 

material was deposited in shallow current-swept marine 

water. Most of the fresh-water and land animals, 

except birds, were probably derived from the mainland 

and represent presumably drift carcasses stranded on 

the shore of the island formed by the Palos Verdes Hills 

during Palos Verdes time. 

A beach facies, in which fossils occurred in cross- 

laminated sand, was formerly represented at locality 

109 in San Pedro, at Palos Verdes and Eighth Streets. 

The fossils, all more or less worn and broken, include 

numerous specimens of small gastropods, "Nassa" 

perpinguis, Mitrdla carinata, Olivella biplicata, and 

Olivella pedroana. None of the southern species char 

acteristic of the protected shallow-water facies were 

found at this locality, but the collection consists of only 

48 species. 

An exceptional faunal association occurs at localities 

108 (Arnold's Crawfish George's locality) and 107. 

Both localities are on the east coast, near Cabrillo 

Beach, and are farther south than other 'Palos Verdes 

localities. None of the characteristic southern species 

occur at these localities. On the contrary, the collections 

include Fusitriton oregonensis, Exilioidea rectirostris, 

Boreotrophon aff. B. multicostatus, Nucella lamellosa, and 

Amphissa columbiana, all northern species not found at 

other Palos Verdes localities. The northern Boreo 

trophon pedroanus occurs at locality 108 and also at 

locality 121, where it is associated with the southern 

Crassinella and Trachycardium procerum. A similar 

mixed association was represented at Deadman Island, 

where Crickmay 22 found the northern or essentially 

northern Fusitriton oregonensis ["Argobuccinum"], Nep- 

tunea tabulata [" Chrysodomus"], Boreotrophon "pacifi- 

cus" [" Trophon"], Nucella lamellosa [" Thais"}, and 

Amphissa columbiana associated with the southern 

Crassinella branneri. 

21 Miller, L. H., Further bird remains from the upper San Pedro Pleistocene: 

Condor, vol. 32, pp. 116-117, 1930. 

M Crickmay, C. H., op. cit. (Jour. Ocol., vol. 37), pp. 631-632, 1929.


Owing to the prevalence of southern species in the 

Palps Verdes at most localities, Arnold 23 thought that 

during Palos Verdes time the temperature of the water 

was as warm as at San Pedro at the present time and 

probably warmer. Smith 24 estimated that the tem 

perature was 4° F. higher than at present and that the 

fauna is probably interglacial, and Gale 2S assigned it to 

the last interglacial period. This matter .and the 

exceptional fauna! association at localities 107 and 108 

are considered under the heading " Glacial-interglacial 

assignments," page 100.° 

AGE AND CORBELATION 

CORRELATION WITHIN PALOS VERDES HILLS 

Wherever the Lomita marl and Timms Point silt are 

found they are at the base of the Pleistocene strata. 

In one area, central San Pedro, the Timms Point silt 

overlies the Lomita marl. The Lomita marl is inter 

preted as representing deposition in clear water during 

a period of varying duration from place to place begin 

ning with the early stage of the Pleistocene transgression 

and resulting in calcareous sediments ranging in thick 

ness from a few inches to about 275 feet. The greatest 

thickness of calcereous -sediments is in the Gaffey 

syncline, which was protected from the flood of granitic 

sand derived from the north by the growing Gaffey 

anticline. 26 The Timms Point silt is interpreted as 

representing deposition in less clear water during a 

period also of varying duration, beginning with the 

early stage of the Pleistocene transgression. In central 

San Pedro the deposition of silt began after the deposi 

tion of calcareous sediments ended. Though represent 

ing varying duration and despite the superposition in 

central San Pedro, the Lomita marl and Timms Point 

silt are thought to be essentially synchronous on both 

stratigraphic and paleontologic grounds. The faunas 

of these two formations have much in common, owing 

doubtless to the prevailing moderate-depth facies of 

both formations. The principal faunal differences are 

attributed to the absence of shallow-water and 25- 

fathom to 50-fathom facies in the Timms Point silt 

and to the presence, in that formation of northern 

pelecypods. The calcareous silt occurring in pockets 

at the base of the Timms Point silt at Timms Point is 

lithologically and faunally indistinguishable from parts 

of the Lomita marl.' The marl in the lower part of the 

Lomita in central San Pedro is probably the equivalent 

of the lower part of the Timms Point silt at Timms 

Point. Both marl and silt contain the northern 

Thracio, trapezoides, not found elsewhere in the Lomita. 

Much of the San Pedro sand is younger than the 

Lomita marl and Timms Point silt, but locally parts of 

the San Pedro are clearly of the same age as those 

formations. Fossiliferous San Pedro sand in San Pedro 

is younger than the Lomita and Timms Point of that 

area. Fossils occur, however, at the base of the San 

Pedro sand immediately above the contact with Mio 

cene mudstone, at locality 64, on the north flank of the 

Gaffey anticline, along Bent Spring Canyon. The 

fossiliferous silty sand at that locality and overlying 

sand and gravel are without any reasonable doubt the 

equivalent of calcareous strata of the Lomita marl on 


Pleistocene of San Pedro, Calif.: California Acad. Sci. Mem., vol. 3, p. 29, 1903. 

24 Smith, J. P., Climatic relations of the Tertiary and Quaternary faunas of the 

California region: California Acad. Sci. Proc., 4th ser., vol. 9, p. 137,1919. 

2(1 Grant, U. S., IV, and Gale, H. R., op. cit. (San Diego Soc. Nat. History Mem., 

vol. 1), p. 73, 1931. 

28 Reed, R. D., Geology of California, p. 259, Am. Assoc. Petroleum "Geologists. 

Tulsa, Okla., 1933. 

the opposite flank of the Gaffey anticline. Despite the 

difference in the character of the sediments, the faunal 

association in the San Pedro sand at locality 64 is 

virtually indistinguishable from that in calcareous 

Lomita sediments indicating a depth of between 25 and 

50 fathoms. Furthermore, the same faunal association 

is found nearby at locality 65 in marly silty sand at the 

very top of about 100 feet of San Pedro sand and gravel. 

This does not mean necessarily that the intervening 100 

feet of sand and gravel were deposited at depths of 

between 25 and 50 fathoms, for the fossiliferous strata 

at locality 65 may represent a period when rate of sub 

sidence outran rate of deposition of sand and gravel. 

The occurrence of the fossils in silty sand or marly silty 

sand at localities 64 and 65 indicates a different environ 

ment from that of the intervening clean coarse sand 

and gravel. 

The marine terrace deposits, even those on the oldest 

terraces, are thought to be younger than the lower Pleis 

tocene formations. If it be assumed that the entire 

present area of the Palos Verdes Hills acted as a unit 

during the intermittent emergence that produced the ter 

races, the present east and north borders of the hills, where 

the lower Pleistocene strata are found at or near sea 

level, were submerged to a depth of at least 1,300 feet 

when the emergence began. No sediments in the lower 

Pleistocene formations are interpreted as representing 

a depth as great as that. The Timms Point silt and the 

lower part of the Lomita marl are interpreted, however, 

as representing depths of between 50 and 100 fathoms 

(300 to 600 feet). So far as inferred depth is concerned, 

such sediments qualify as being contemporaneous with 

some of the intermediate terraces. It may be argued 

that the terrace deposits are younger than the defor 

mation assigned to the middle Pleistocene. The 

absence of deformation of intermediate and oldest 

terraces is not opposed, however, to this possible 

correlation, for. the lower Pleistocene strata, aside from 

tilting resulting probably from uplift, are not deformed 

except along the north border of the hills, where the 

youngest terrace itself is mildly or moderately deformed. 

The presence of large cobbles and boulders in the Lomita 

marl where it rests on its basement and the occurrence 

of a shallow-water facies in that formation are opposed 

to the correlation. In view of these relations it is 

inferred that the thin veneer of deep-water and moder 

ate-depth sediments deposited during the relatively 

brief episodes when the oldest and intermediate terraces 

were formed was removed by marine erosion during the 

formation of successively younger terraces. 

AGE 

The formations in the San Pedro district that are 

considered of Pleistocene age are assigned to that epoch 

because they contain a fauna more modern than that of 

Coast Range formations assigned to the upper Pliocene. 

The division of Pleistocene into lower, middle, and 

upper parts is relative and more or less arbitrary. It 

is adopted for convenience and is based on events in 

the geologic history of the Palos Verdes Hills. Both 

lower and upper Pleistocene strata may include deposits 

of middle Pleistocene age. 

It was formerly thought that the marine Pleistocene 

formations contain no extinct genera of mollusks. 

Elassum and Calicantharus are, however, not known 

to be living. Elassum is associated with species of 

moderate-depth facies and may be found to be living 

when the moderate-depth fauna of southern California

is better known. Calicantharus is associated with 

species of shallow-water 'and moderate-depth facies. 

Inasmuch as the shallow-water mollusks of southern 

California and adjoining regions are fairly well known, 

CaliccLntharus is quite certainly extinct in shallow 

water. As it is much larger than Elassum, it would 

probably be known by this time if it were living at 

moderate depths. 

The percentage of species that are not known to be 

living is low, not more than 5 to 10 percent. The 

percentage is, however, of little value, for it depends on 

what is meant by the expression "not known to be 

living." Many species and varieties generally placed 

Gastropods: 

Species 

Pomaulax turbanicus pctrothauma 

(Berry). 

Elassum californicum (Dall and 

Bartsch). 

"Nnssa" fossata coilotera Woodring, 

n. vnr. 

Tritonalia coryphaona Woodring, n. sp. 

Borcotrophon cf. B. paciflcus (Dall).--- 

Borcotrophon aft. B. multicostatus 

(Eschscholtz). 

Borcotrophon aft. B. stunrti (Smith)... 

Borcotrophon cf. B. raymoudi (Moody). 

Pelccypods: 

* 


marl Lomita 1 

X 

X 

X 

X ' 

X 

X 

XXXX X 

X 

X 

X 

silt Timms Point 

"X 

X 

(?) 

"X 

X 

8 X 

X 

11 X 

X 

'< X 

X 

(?) 

i'X 

X 


Pleistocene mollusks not known to be living 

San Pedro 1 sand X 

X 

X 

X 


inclusive, represent one facies, rock-cliff and tide-pool, 

and the number of species in that facies is small, not 

more than about 60. The apparently extinct species 

from the fourth, third, and second terraces are from the 

exceptional localities 86, 93, and 105, with the exception 

of Cerithiopsis arnoldi fossilis. The Palos Verdes sand 

is the only terrace deposit that has a fauna.of large 

size, about 250 species, comparable to that of the 

Lomita, Timms Point, and San Pedro. It includes, 

however, a much smaller number of moderate-depth 

species than the lower Pleistocene faunas. 

LOWER PIEISTOCENE 

The Lomita marl, Timms Point silt, and San Pedro 

sand are assigned to the lower Pleistocene. They 

constitute a well-defined stratigraphic and chronologic 

unit. Owing to the presence of apparently extinct 

species generally considered characteristic of the 

Pliocene, Arnold 27 and Smith 28 assigned the Timms 

Point silt to the upper Pliocene, and Grant and Hert- 

lein 29 refer the Lomita marl and possibly part of the 

Timms Point to the upper Pliocene. The species 

generally considered characteristic of the Pliocene are 

as follows: , 

Fossils apparently extinct that are generally considered characteristic 

of Pliocene, which occur in strata of San Pedro district assigned 

to lower Pleistocene 

Pelecypods: 

Species 

Lomita 

marl 

(?) 

X 

X 

X 


Timms 

Point 

silt 

(?) 

X 

X 

San 

Pedro 

sand 

None of the preceding species are recorded from the 

Palos Verdes sand, with the exception of'Arnold's record 

of Crepidula ^princeps ["grandis"], an occurrence not 

now subject to verification owing to the destruction of 

Deadman Island. 

If the Lomita marl is assigned to the upper Pliocene, 

it follows, from the interpretations adopted in the pre 

sent report, that the Timms Point silt and also a varying 

thickness of the San Pedro sand, depending on the 

faunal facies, and the entire exposed thickness at Bent 

Spring Canyon 'also ar'e to be assigned to the upper 

Pliocene. That is, the division between Pliocene and 

Pleistocene would have no satisfactory faunal or stra 

tigraphic basis in the San Pedro district. If, on the 

contrary, the preceding species are regarded as survivors 

from the Pliocene and the locally extinct Anadara 

proper and the extinct Lyropecten are considered char 

acteristic of the upper Pliocene, 30 the division between 

Pliocene and Pleistocene in the Coast Range marine 

section has a more satisfactory faunal basis. Faunal 

criteria for distinguishing marine Pliocene and Pleisto 

cene strata are necessarily local and may be selected on 

» Arnold, Ralph, The paleontology and stratigraphy of the marine Pliocene and 

Pleistocene of San Pedro, Calif.: California Acad. Sci. Mem., vol. 3, p. 16,1903. 

" Smith, J. P., Climatic relations of the Tertiary and Quaternary faunas of the 

California region: California Acad. Sci. Proc., 4th ser., vol. 9, pp. 150-151,1919. 

29 Grant, U. S., IV, and Hertlein, L. Q., Pliocene correlation chart: California Div. 

Mines Bull. 118, pt. 2, pp. 201-202, 1941. 

so Woodring, W. P., Stewart, Ralph, and Richards, R. W., Geology of the Kettle- 

man Hills oil field, Calif.: U. S. Geol. Survey Prof. Paper 195, p. H4,1940 [1941]. 

(?) 

a basis of greatest practical utility. The suggested 

faunal division has the practical advantage of agreeing 

with diastrophic history to the extent that as thus de 

limited the Pleistocene begins with a marine transgres 

sion both in the San Pedro district and on the borders 

of the Ventura Basin. In an area of continuous Plio 

cene-Pleistocene marine deposition such as the western 

part of the Ventura Basin there are bound to be transi 

tional strata, and the lower part of the Palos Verdes 

Hills strata assigned to the lower Pleistocene also is 

more or less transitional. Regardless of age designa 

tions paleontologists are in essential agreement concern 

ing correlation of the faunal zones. 

Of the identified mollusks, the following were found 

only in each of the three lower Pleistocene units: 

Mollusks found only in Lomita marl 

Gastropods: 

Acmaea ochracea Dall. 

Solariella rhyssa Dall. 

Vitrinella sylvania (Dall). 

Pomaulax turbanicus petrothaurna (Berry). 

"Amphithalamus" lacunatus Carpenter? 

Cerithiopsis cf. C. gloriosa Bartsch. 

Cerithiopsis willetti Bartsch, n. var.? 

Caecum grippi Bartsch. 

Macron aethiops (Reeve). 

Tritonalia coryphaena Woodring, n. sp. . 

Acteon breviculus Dall. 

Williamia peltoides (Carpenter). 

Pelecypods: 

Chlamys opuntia (Dall). 

Ostrea megodon cerrosensis Gabb. 

Ventricola fordii (Yates). 

Mollusks found only in Timms Point silt 

Gastropods: 

Pupillaria cf. P. salmonea (Carpenter). 

Macheroplax cf. M. varicosa (Mighels and Adams). 

Velutina laevigata (Linne") ? 

Boreotrophon cf. B. raymondi (Moody). 

Pelecypods: % 

Thyasira disjuncta (Gabb). 

Macoma calcarea (Grnelin), small var. 

Mya truncata Linne'. 

Panomya beringianus Dall, small var. 

Pandora grandis Dall. 

Mollusks found only in San Pedro sand 

Gastropods: 

Vitrinella thomasi Bartsch. 

Cyclostremella coronadoensis (Arnold). 

Cerithiopsis antemunda Bartsch. 

The most distinctive Lomita marl species are apparently 

extinct (Pomaulax turbanicus petrothauma, Tritonalia 

coryphaena, Chlamys opuntia, Ostrea megodon 

cerrosensis}, belong to the moderate-depth group (Solariella 

rhyssa, Acteon breviculus), or represent evidently 

an exceptional environment (Ventricola fordii). The 

most distinctive Timms Point species are northern 

(Velutina laevigata, all the pelecypods) or represent the 

moderate-depth group (Macheroplax). The three species 

from the San Pedro sand are not particularly 

distinctive. The faunal similarity between the Lomita 

marl and Timms Point silt is shown by the following 

table, in which species found only in those units are 

listed: 

Mollusks found in Lomita marl and Timms Point silt but not in 

other Pleistocene units 

Gastropods: 

Solariella peramabilis Carpenter. 

Pelecypods: 

Cyrilla munita Dall. 

Hyalopecten vancouverensis (Whiteaves). 

Mercenaria perlaminosa Conrad. 

Thracia trapezbides Conrad.

The species in the preceding list belong in the 

moderate-depth group, with the exception of the appar 

ently extinct Mercenaria perlaminosa. 

Little significance can be attached to the apparently 

restricted occurrence of the species in the preceding 

lists, except insofar as faunal facies has a restricted 

distribution. The effect of faunal facies is well shown 

by the table on page 93, which lists 19 species found in 

the San Pcd.ro sand only at localities inferred to repre 

sent a moderate-depth facies. All except one of the 19 

species occur in the Lomita or Timms Point, and all 

except 3 occur in both. 

UPPER PLEISTOCENE 

The marine terrace deposits are assigned to the upper 

Pleistocene. They are thought to be considerably 

younger than the lower Pleistocene strata. Duration of 

the time interval inferred to have intervened, between 

deposition of the lower Pleistocene and planation of the 

oldest terrace is, however, not known. That interval is 

considered arbitrarily to represent approximately the 

middle third of Pleistocene time. There is no faunal 

basis for referring the marine terrace deposits to more 

than one division of the Pleistocene, though it is 


improbable that terrace deposits of lower Pleistocene 

age could be distinguished from those of upper Pleis 

tocene age on faunal grounds. 

Fossils from the terraces that represent a rock-cliff 

and tide-pool facies are indistinguishable regardless of 

whether they are from the twelfth or second terrace, 

with the exception that a southern species (Acanthina 

lugubris) was found on the fourth and second terraces. 

That facies.is not known to occur, however, on the first 

terrace. Deposits on the fourth to first terraces are the 

only terrace deposits now known to contain a protected 

shallow-water facies, a facies that, includes southern 

species in the faunas from those deposits. The occur 

rence of certain southern species affords a basis for 

distinguishing a protected shallow-water facies of at 

least the fourth to first terraces from the same facies in 

the next older Pleistocene strata in which that facies 

occurs the San Pedro sand. It is, however, of doubt 

ful value as a basis for correlation, for the duration of the 

unknown conditions that determined the northward 

extension of range of the southern species is not known. 

They were formerly not known to occur in terrace 

deposits older than the Palos Verdes sand. 

The following identified species were found only in 

terrace deposits older than the Palos Verdes sand: 

Mollusks found only in upper Pleistocene marine terrace deposits older than Palos Verdes sand 

Species 

Gastropods: 

Acmaca persona "Eschscholtz" Rathke. _____________ __________ 

Haliotis cracherodii Leach___________.__ ___________ __________ 

PseudorotelJa supra vallata (Carpenter) __ ___ _ ____ ___________ 

Alvania almo Bartsch_____ ________ ___ ____________________ 

Rissoina cosmia (Bartsch) _____________ _______________________ 

Truncatella stimpsoni Stearns_-----_-__--_-_____- __ __________ 

Fartulum orcutti (Dall) _______________________________________ 

Mitra fultoni E. A. Smith____________________________._.______ 

Jaton santarosanus (Dall) _____________________________^_______ 

Tr.\tonalia circumtexta aurantia (Stearns) ____._---_-___---_-____ 

Tritonalia gracillima (Stearns) ?_______________________________. 

Acanthina lugubris (Sowerby)___--------_-----------__- _.-___ 

Pelecypods: 

Botulina "opifex (Say)"_____ _______ ___________________________ 

Milneria kelseyi Dall. _______________________ ____ _____________ 

Trigoniocardia biangulata (Sowerby) __-_______--__-_-_---_____ 

Identified species found only in the large Palos 

Verdes fauna arc as follows. This list would be larger 

if Arnold's records included in the tables on pages 

87-89 wore added. 

Mollusks found only in upper Pleistocene Palos Verdes sand 

Gastropods: 

Tcgula raarcida (Gould) [''pulligo"]. 

GalJiostoma eximium (Reeve). 

Neverifca reclusiana imperforata Dall. 

"Nassa" fossata coilotera Woodring, n. var. 

"Nassa" delosi Woodring, n. sp. 

"Nassa" cerritensis Arnold. 

Nucella biserialis (Blainville). 

Forreria belcheri (Hinds). 

592787 45- 

12- 

X 

X 

X 

9 

X 

X 

8 

(?) 

X 

6 

(?) 

X 

Terrace 

5 

(?) 

Pelecypods: 

Anadara perlabiata (Grant and Gale). 

Dosinia ponderosa (Gray). 

Amiantis callosa (Conrad). 

Chione gnidia (Broderip and Sowerby). 

"Chione" picta Dall. 31 

Trachycardium procerum (Soerby). 32 

Trachycardium elatum (Sowerby). 

A considerable number of additional species were 

found in terrace deposits but not in the lower Pleisto 

cene strata. 

81 Reported orally by Chace from second terrace on Fifteenth Street near Leland« 

32 One specimen reported by Ralph Arnold from San Pedro sand at Deadman Island 

(Arnold, Ralph, op. cit. (California Acad. Sci. Mem., vol. 3), p. 139,1903). 

X 

X 

4 

Xx 

X 

X 

X 

X 

X 

X 

3 

X 

X 

X 

X 

2 

X 

X 

X 

X 

X 

(?) 

X 

X 

X


Mollusks found in upper Pleistocene terrace deposits, including Palos Verdes sand, but not in lower Pleistocene strata 

Species 

Gastropods : ' 

Tegula aureotincta (Forbes) _ _ . ___ _ __ ____ ___ 

Erato columbella Menke____ ._ _ __ __ _-_ 

Pelecypods : 

Nucula suprastriata Arnold __________ __ ____ 

Pecten vogdesi Arnold. ___ __ ___ _________ 

Crassinella nuculiformis Berry _ _____ __ _.__ ____ 

The most distinctive species of the terrace deposits 

older than the Palos Verdes sand are representative 

of the rock-cliff and tide-pool facies. Trigoniocardia 

biangulata is a southern species, close to the present 

northern limit of its range, from the exceptional second 

terrace locality 105. The most characteristic Palos 

Verdes species are southern species either well north 

of their present northern limit or close to it. Pecten 

vogdesi, Crassinella branneri, Crassinella nuculiformis, 

arid Diplodonta sericata are additional southern species 

of the Palos Verdes found also in deposits on the fourth 

and second terraces at the exceptional localities 86 or 

105. The Palos Verdes list includes one northern 

species close to the present southern limit of its range 

(Tegula marcida). The apparently restricted occur 

rence of terrace fossils, like the occurrence of the lower 

Pleistocene species, is evidently controlled principally 

by facies restriction. 

GLACIAL-INTERGLACIAL ASSIGNMENTS 

If the strata in the San Pedra district are Pleistocene, 

they are presumably synchronous with Pleistocene 

Pleistocene unit 

Palos Verdes sand.. 

San Pedro sand .... 

\ 


Lomita marl. ...... 

12 

X 

9 8 6 

X 

X 

X 

Terrace 

5 

X 

4 

.X 

X 

X 

X 

X 

X 

3 

X 

X 

2 

X 

X 

X 

(?) 

X 

X 

--X X 

X 

X 

X 

X 

1 

(Palos 

Verdes 

sand) 

glacial and interglacial stages. There is, of course, 

no direct evidence of synchroneity, for Pleistocene 

glaciation is not certainly recognized in southern Cali 

fornia below altitudes of about 10,000 feet. Eaton's 

views 33 represent those of geologists who assign glacia 

tion to the upper Pleistocene and, therefore, consider 

the lower Pleistocene marine strata preglacial. In the 

present report Pleistocene time is accepted by definition 

as beginning with the advance of the first continental 

ice sheet and ending with the withdrawal of the last, 

an admittedly unsatisfactory definition for the Coast 

Range marine section. 

The occurrence of northern species, particularly in 

the Timms Point silt, and of southern species, particu 

larly in the Palos Verdes sand, has stimulated considera 

tion of temperature facies and glacial-interglacial 

assignments. Opinions are summarized in tabular 

form as follows: 

33 Eaton, 'J. E., Divisions and duration of the Pleistocene in southern California: 

Am. Assoc. Petroleum Geologists Bull., vol. 12, pp. 132-133, 1928. 

Estimated temperature facies and glacial-interglacial assignments of Pleistocene strata of San Pedro district 

Arnold, 1903 » 

As warm as at 

present time 

or warmer. 

Cold-water, transitional 

from 

earlier northern. 

Assigned to upper 

Pliocene. 

Decidedly 

northern or 

boreal. 

Smith, 1919 2 

Temperature about 66° F., 

about 4° higher than at 

present. Probably interglacial. 

Temperature probably 

about same as that of 

Puget Sound, 50° F. 

Probably corresponds to 

time of maximum galciation. 

Assigned to upper Pliocene. 

Temperature probably 

about same as that of Puget 

Sound, 50° F. 

Hay, 1927 3 

Aftonian interglacial 

stage. 

Nebraskan glacial 

stage. 

Glacial period was 

approaching. 

1 Arnold, Ralph, California Acad. Sci. Mem., vol. 3, pp. 16, 20, 29, 1903. 

2 Smith, J. P., California Acad. Sci. Proc., 4th ser., vol. 9, pp. 136-137, 151, pi. 9, 

1919. 

3 Hay, 0. P., Carnegie Inst. Washington Pub. 322B, pp. 166-173,1927. 

< Crickmay, C. H., Jour. Geology, vol. 37, pp. 622-632, 1929. 

Crickmay, 1929 *" 

Only about 5 percent of species 

in Arnold's upper San Perdo 

of Deadman Island are 

autochthonous, and they 

indicate a temperature like 

that of San Pedro at present. 

Arnold's lower San Pedro of 

Deadman Island represents 

climate as warm as that of 

San Pedro at present or 

slightly warmer. Coldwater 

species derived from 

older strata. 

6 zones of different temperature 

facies only 1 of which, 

zone 5, is decidedly coldwater 

and doubtless represents 

a glacial stage. 

Gale, 1931 s 

Later part of third 

interglacial stage 

(Sangamon). 

Early part of second 

interglacial stage 

(Yarmouth). 

Second glacial stage 

(Kansan). 

First interglacial 

stage (Aftonian), 

assigned to Las 

Posas zone. 

Grant, 1937 « 

X 

X 

X XXXXX 

X 

X X 

X 

X X 

X 

X 

Mean annual sea surface 

temperature about 63° 

F. Present mean annual 

sea surface temperature 

at San Pedro 

61° F. 

Temperature fluctuating, 

possibly 50° to 60° F. 

Mean annual water temperature 

possibly 50° 

to 52° F. 

Temperature about 60° 

to 62° F. 

« Grant, U. S., IV, and Gale, H. R., San Diego Soc. Nat. History Mem., vol. 1, 

pp. 71-74, table 3 (p 75), 1931. 

6 Grant, U. S., Am. Assoc. Petroleum Geologists, Program 22d Ann. Meeting, pp. 

69, 71,1937.

It is apparent from the preceding table that opinions 

concerning the temperature facies vary widely. The 

writers cited agree, however, that the Timms Point 

fauna represents cool water, or at least includes a 

cool-water zone, and is doubtless glacial, and most of 

them agree that the Palos Verdes fauna represents 

warm water and is doubtless interglacial. Assignment 

to definite glacial and interglacial stages is so speculative 

that it is not considered further. 

That interpretation of the temperature facies is not 

a, simple matter is evident from the varying opinions. 

If the Timms Point fauna and San Pedro sand fauna 

represented a southward displacement of the isotherms 

of 1,500 miles and the Palos Verdes fauna represented 

a northward displacement of about 650 miles, as Smith 

thought, there would be no argument about the matter. 

It is quite clear that the faunas of the Timms Point 

and the San. Podro are not Puget Sound faunas and 

that the Palos Verdes fauna is not a Magdalena Bay 

fauna, despite the presence of species now riving in 

those areas and not at San Pedro. All the faunas 

considered by the writers cited contain both northern 

and southern species. Most of the writers who have 

considered the matter relied on the preponderance of 

one group and ignored the other. Crickmay 3V who. 

protested justly against such treatment, thought the 

problem could be resolved to at least a certain extent 

by careful zoning and discrimination of detrital 

(derived) fossils and fossils that lived at the time the 

sediments were deposited (autochthonous). Detrital 

fossils are expectable particularly in the Palos .Verdes 

sand, which in extensive areas bevels fossiliferous 

lower Pleistocene strata. Before Deadman Island was 

destroyed the Pleistocene strata exposed there yielded 

fossils that were buried in sediments accumulating off 

shore. Many San Pedro extra-limital records of 

Recent mollusks are based doubtless on these detrital 

fossils. Crickmay's criteria for the recognition 

of detrital fossils are, however, of doubtful value. 

Should broken and worn specimens be represented in 

a collection of otherwise well-preserved specimens, the 

broken and worn specimens may very well be detrital. 

Unequivocal examples of such occurrence are not 

recognized in the collections at hand. Crickmay's 

opinion 35 that 95 percent of the species in the sand and 

gravel of the Palos Verdes at Deadman Island are 

detrital because they are represented by wave-worn or 

broken specimens is considered erroneous. A large 

proportion of specimens that occur in gravel are cer 

tain to be worn and broken regardless of whether they 

are detrital or not. His opinion 30 that all the speci 

mens of Cerastoderma nuttallii ["Cardium corbis"] in 

the Timms Point silt and San Pedro sand of Deadman 

Island arc detrital and derived probably from a hypo 

thetical cold-water zone does not take into considera 

tion the corroding of Cerastoderma shells, which is due 

presumably to peculiarities of shell structure. Fossil 

Cerastodermae are generally corroded. Nevertheless 

the uncorroded and perfectly fresh specimen of the 

essentially northern Cerastoderma, nuttallii shown on 

plate 34, figures 16 and 17 was collected from the San 

Pedro sand at Deadman Island in association with the 

equally well-preserved specimen of the essentially 

southern Trachycardium quadragenarium shown in 

figures 18 and 19 on the same plate. 

84 Crickmay, C. H., The anomalous stratigraphy of Deadman's Island, Calif.: 

Jour. Geology, vol. 37, pp. 618-621. 

« Idem, p. 632. 

8« Idem, p. 630. 


A ready solution of the problem of the occurrence 

of northern and southern species in the same strata is 

not apparent. Consideration of the following subjects 

may, however, aid in reaching a solution. It will be 

observed that none of the writers cited considered the 

terrace faunas older than the Palos Verdes sand, as 

those faunas were unknown to them. 

FAUNA! FACIES 

Comparison of the same faunal facies is an essential 

requirement for interpretation of temperature facies 

in terms of latitude. Several faunal facies are repre 

sented in the Pleistocene strata. A shallow-water 

facies is recognized in the Lomita marl, San Pedro sand, 

and Palos Verdes sand. A particular type of shallow- 

water facies (rock-cliff and tide-pool) is recognized in 

terrace deposits older than the Palps Verdes sand. The 

shallow-water facies of the Lomita marl contains an 

apparently extinct oyster (0. megodon cerrosensis] 

closely related to a Recent southern species. The 

shallow-water faunas in the San Pedro sand and in the 

Palos Verdes sand are so similar that there is some doubt 

about the age assignments. Nevertheless they have 

been discriminated, whether correctly or not, by the 

presence of southern species in the Palos Verdes sand 

and their absence in the San Pedro sand. The rock- 

cliff and tide-pool facies of the twelfth to fifth terraces, 

inclusive, contains no species entirely beyond its present 

range but includes northern and southern species close 

to the limits of their range. The same facies on the 

fourth to second terraces, inclusive, includes northern 

and southern species of both groups. 

A moderate-depth facies is thought to characterize 

much of the Lomita marl and Timms Point silt and 

also the San Pedro sand at a few localities. The cool- 

water aspect of the Timms Point fauna and locally of 

the faunas of the Lomita and San Pedro is attributed 

in large measure to this depth facies. The Timms 

Point silt contains Puget Sound species, but many 

Timms Point species do not range as far north as 

Puget Sound, and others are not found in shallow water 

hi Puget Sound. 

MIXED FAUNA! FACIES 

Most fossil assemblages, at least most large Tertiary 

and Pleistocene marine assemblages, represent death 

associations, not life associations. Though it is fre 

quently difficult or impossible to recognize members 

of different life associations in a mixed fossil assemblage, 

some aspects of this matter deserve consideration. 

The shallow-water Olivella biplicata and Conus 

californicus are represented in Timms Point collections. 

The. specimens are, however, worn and broken. Inas 

much as shallow-water to moderate-depth and moder 

ate-depth species in the same collections also are 

represented by some broken or worn specimens, the 

evidence is inconclusive that the shallow-water species 

did not live with the others. 

The rock-cliff and tide-pool facies of terrace faunas 

older than the Palos Verdes sand includes species that 

live below low-tide line in the latitude of-San Pedro. 

For that reason Berry 37 thought that the chiton fauna 

from the Chaces' locality on the second terrace near 

Point Fermin is like that living along the shore of 

Monterey and San Luis Obispo Counties farther north. 

The Chaces 38> thought, .however, that the species of 

mollusks now living below low-tide line were carried 

in by storm waves and mixed with tide-pool species. 

a' Berry, S. S., op. cit. (California Acad. Sci. Proc., 4th ser., vol. 11), p. 409,1922. 

ss Chace, E. P., and E. M., op. cit. (Lorquinia, vol. 2, No. 6), p. 43,1919.


That explanation is preferred to Berry's interpretation. 

The fauna from the fourth terrace at locality 86 and 

that from the second terrace at locality 105 represent 

mixed rock-cliff and tide-pool and off-shore shallow- 

water associations with the probable addition of some 

moderate-depth species at locality 105. This mixture 

is attributed to storm-wave and along-shore current 

transportation. The off-shore shallow-water species 

include southern species found also in the Palos Verdes 

sand. 

The unusual Palos Verdes fossils from localities 107 

and 108 (Arnold's Crawfish George's locality) may 

represent a mixed shallow-water and moderate-depth 

association. Inasmuch as these localities faced the open 

ocean during Palos Verdes tune whereas the localities 

containing the usual Palos Verdes association faced the 

strait separating the- island from the mainland, it has 

been suggested that the northern and moderate-depth 

species from localities 107 and 108 were transported 

into shallow-water by storm waves. 39 Mollusks that live 

below low-tide line are washed up frequently on beaches 

during storms. The usual finds represent species that 

live just below low-tide line or at depths of a few 

fathoms. Species that are not known to live at depths 

of less than 10 fathoms are also found rarely after storms. 

They represent evidently unusual occurrences, such as 

those found clinging to the holdfast of long kelp stalks. 

Jaton santarosanus, which has been dredged at depths 

of 16 and 82 fathoms but is not known to live at 

shallower depths, is reported to have been found on 

kelp washed in by storm waves. That species is repre 

sented probably by an imperfect specimen from the 

second terrace at locality 105. Storm transportation 

could not account, however, for the occurrence at 

locality 108 of Fusitriton oregonensis and Exilioidea 

rectirostris, the present known minimum depth of which 

at the latitude of San Pedro is 80 fathoms, unless these 

species lived at shallower depth during Pleistocene time. 

Contrary to expectation on the hypothesis of storm 

transportation, markedly northern and intermediate- 

depth forms have not been found in terrace deposits on 

the exposed south and west coasts. The unusual species 

from localities 107 and 108 may be detrital fossils 

derived from the lower Pleistocene strata in which they 

are known to occur. Nevertheless, in physical condition 

they are indistinguishable from other species collected 

at those localities. If they are detrital, they are expect 

able in greater abundance at localities farther north 

where the Palos Verdes sand rests on lower Pleistocene 

strata. A specimen of Boreotrophon pedroanus from 

locality 121 is the only representative of the northern 

and moderate-depth group in the Palos Verdes of that 

area. Arnold 40 realized that the fauna from his Crawfish 

George's locality is exceptional, but he did not discuss 

its unusual features. Owing to the unusual faunal 

association, the deposits at that locality have been 

referred to the Timms Point silt 41 and San Pedro 

sand. 42 

EFFECTS OF CHANGES IN OUTLINE OF COAST 

The Pleistocene elephants found on the Channel 

Islands, 43 off the coast northwest of the Palos Verdes 

Hills, indicate that during a still undetermined part 

" Woodring, W. P., op. cit. (Am. Jour. Sci., 5th ser., vol. 29), p. 304, 1935. 


Pleistocene of San Pedro, Calif.: California Acad. Sci. Mem., vol. 3, p. 26,1903. 

« Ashley, O. H., The Neocene stratigraphy of the Santa Cruz Mountains of Cal 

ifornia: California Acad. Sci. Proc., 2d ser., vol. 5, p. 341,1895. 

42 Berry, S. S., op. cit. (California Acad. Sci. Proc., 4th ser., vol. 11), p. 411, 1922 

43 Stock, Chester, Exiled elephants on the Channel Islands, Calif.: Sci. Monthly, 

vol. 41, pp. 205-214, 10 figs., 1935. 

of Pleistocene tune these islands were joined 'to the 

present western terminus of the Santa Monica Moun 

tains. During early Pleistocene time northern species, 

such as Patinopecten caurinus, had a range extending 

southward at least to the San Pedro district. If the 

peninsula came into existence after the lower Pleisto 

cene strata were deposited, the northern species may 

have become extinct locally owing to changes in oceanic 

circulation and then were not reestablished in the area 

of local extinction after disappearance of the peninsula. 

The. peninsula would protect coastal-water to the 

south from southward-drifting cold water, as has been 

suggested by Gale. 44 A land mass farther south a 

relic of ancient Catalinia joining the islands of Cata- 

lina, Santa Barbara, San Nicolas, and San Clemente 

also would have an effect in providing a suitable habitat 

for the markedly southern species characteristic of the 

Palos Verdes Hills. Land areas off the coast of 

southern California are, however, probably not later 

than middle Pleistocene, for marine terraces on the 

Channel Islands and on the islands farther south, 

except Catalina, show partial or complete submergence, 

presumably during late Pleistocene time. At all events 

Santa Monica is the northernmost known locality for 

the occurrence of southern species characteristic of the 

Palos Verdes sand, indicating that the inferred penin 

sula was in existence during late Pleistocene time and 

that it had a profound effect on the distribution of 

marine animals. 

EFFECTS OF LOCAL TEMPORARY CHANGES IN OCEAN TEMPERATURE 

The occurrence of northern or of southern species in 

strata characterized by the preponderance of species of 

the other group may be due to local changes in ocean 

temperature caused by, temporary changes in oceanic 

circulation. Local fluctuations of this character re 

sult in the distribution of marine animals but not of 

breeding communities beyond their normal range, 

particularly in temperate regions. The reported occur- 

ence of the southern 'Anadara multicostata in Balboa 

Bay, almost 100 miles north of its usual northern limit, 

may be an example of a temporary extension of range. 

POSSIBLE CHANGES IN GEOGRAPHIC AND DEPTH RANGE SINCE PLEISTOCENE 

TIME 

Perhaps paleontologists are mistaken in attempting 

to interpret these Pleistocene faunas in terms of the 

present geographic range of the species still living and 

of closely related Recent forms. If it' be assumed that 

the range of some species has changed since Pleistocene 

time owing to changes in physiological characters not 

correlated with changes in available morphological 

characters, difficulties would vanish. That this matter 

is not entirely speculative is indicated by the occurrence 

in the Pliocene strata at Elsmere Canyon of a form of 

the circumboreal Mya truncata,*5 a northern species 

characteristic of the Timms Point silt. At Elsmere 

Canyon it is associated with the essentially northern 

Fusitriton oregonensis and with Lyropecten and other 

forms considered of warm-water aspect. Changes in 

depth range may also have taken place since Pleistocene 

time. Extensive changes of that character would in 

validate conclusions based on present depth range. It 

is improbable, however, that changes in either geo- 

44 Grant, U. S., IV, and Gale, H. R., Catalogue of the marine Pliocene and Pleisto 

cene Mollusca of California: San Diego'Soc. Nat. History Mem., vol. 1, pp. 39, G4,1931 

45 Arnold, Ralph, New and characteristic species of fossil mollusks from the oil 

bearing Tertiary formations of southern California: U. S. Nat. Mus. Proc., vol. 32 

p. 527, pi. 50, fig, 1, 1907.

graphic or depth range have taken place in many of the 

species of a large fauna like that of the Timms Point 

silt and the moderate-depth facies of the Lomita marl. 

INTERPRETATION OF TEMPERATURE FACIES IN TERMS OF POSSIBLE 

GLACIAL AND INTEROLACIAL ASSIGNMENTS 

In summary it may be said that interpretation of the 

temperature facies in terms of possible glacial and inter- 

glacial assignments is so complicated by other possible 

factors that assignments are questionable. It is not 

unreasonable to expect faunal changes in the San Pedro 

district due to glaciation and deglaciation, even though 

it is 1,500 miles south of the southern limit of sea-level 

Pleistocene glaciers. Faunal stratification in the sedi 

ments of areas as far from glaciated regions as the 

equatorial Atlantic is interpreted in terms of inter- 

glacial, glacial, and post-glacial succession. 48 The 

occurrence in Pleistocene strata at Tom.ales Bay, im 

mediately .north of San Francisco Bay, of species north 

of their present range, including Chione undatella and 

Tr achy car dium quadragenarium," suggests an intergla- 

cial fauna. The shallow water faunas of the Lomita 

iriarl, San Pedro sand, deposits on the fourth to second 

terrace, inclusive, and the Palos Verdes sand may be 

interglacial despite apparently conflicting evidence. 

The Timms Point fauna can hardly be interpreted as 

a shallow-water glacial fauna; it may be a moderate- 

depth glacial or interglacial fauna. The faunas from 

the twelfth to fifth terraces, inclusive, might be con 

sidered interglacial. Inasmuch, however, as they do 

not include a southern species (Acanthina lugubris) 

found in the same facies on the fourth and second ter 

races they might be interpreted as glacial. A shallow- 

water northern fauna of the character expectable 

during a glacial stage is not recognized in the entire 

succession of 12 Pleistocene faunas. 

Perhaps the importance of the moderate-depth, 

association has been overemphasized in the present 

report because it was undervaluated previously in 

interpretations of the Pleistocene faunas of the San 

Pedro district. Some writers have briefly discussed 

this matter. Crickmay 48 considered the possibility 

that at least parts of the Timms Point silt represent 

moderate depths. He thought his zone 3 may have 

been deposited in water between 50 and 100 fathoms 

deep and that his zone 4 suggests a depth of 100 fathoms 

or perhaps more estimates agreeing closely with those 

for the entire Timms Point silt in the present report. 

According to Reed, 49 most of the Lomita Foraminifera 

indicate a depth of 50 to 100 fathoms. Grant 60 

thought the Lomita fauna indicates a depth of possibly 

100 to 300 feet (approximately 15 to 50 fathoms). A 

marked feature of the Lomita and Timms Point faunas 

and locally of the San Pedro is the occurrence of species 

or closely related forms known only from Albatross 

dreclgings at depths of 67 to 81 fathoms off Point Loma 

near San Diego (Puncturella delosi, Solariella rhyssa, 

Homalopoma subobsoletum) and of species from Alba 

tross dredgings at depths of 55 to 110 fathoms in the 

same area and 48 to 155 fathoms off the California 

«> Schott, \V., DieForaminiferon indem equatorialen Teil des Atlantischen Ozeans: 

Doutsohen Atlantischen Exped. Meteor, 1925-27, Wiss. Ergebnisse, vol. 3, pt. 3, pp. 1'20- 

130.1935. 

«' Dlckorson, 11. E.. Tertiary and Quaternary history of the Petaluma, Point Reyes, 

and Santa Rosa Quadrangles: California Acad. Sci. Proc., 4th ser., vol. 11, pp. 559-570, 

1922. 'Mason, H. L., Pleistocene floras of the Tomales formation: Carnegie Inst. 

AVashington Pub. 415, pp. 85-87,104-105, tables op p. 104,1934. 

« Crickmay. C. H., op. cit., pp. 624, 626. 


represented, and the probability of finding one or more 

of these few southern species in a small collection of 

fossils from cores or ditch samples is remote. 

Signal Hill. Sand, gravel, and silt underlying 

strata correlated with the Palos Verdes sand at Sig 

nal Hill, near Long Beach, have recently been found 

to be fossiliferous and are correlated with the San 

Pedro sand. 54 

Santa Monica. Pleistocene mollusks, mostly of 

moderate-depth facies, occur in deformed strata at 

localities near Santa Monica. 55 The faunal association 

suggests the Lomita and Timms Point and also parts 

of the San Pedro sand. 

Ventura Basin. An exceptionally thick continuous 

and uniformly deformed section of 20,000 feet of marine 

Pliocene and Pleistocene strata is represented in the 

western part of the Ventura Basin. The part of this 

.section assigned to the Pleistocene is about 6,000 feet 

thick and overlies .Angara-bearing upper Pliocene. 

Various names have been proposed or used for the 

Pleistocene strata: Santa Barbara formation or Santa 

Barbara horizon, upper part of Pico formation, Saugus 

formation, San Pedro formation, Baton's Hall Canyon 

formation, Pressler's Las Posas formation and Kalorama 

member, and his Long Canyon horizon. Lists of fossils 

have been published by Arnold, 56 Eaton, 57 Waterfall, 58 

and Pressler, 59 and selected species were mentioned by 

Bailey. 60 

According to Bailey's description, 61 the lower part 

of the Pleistocene strata assigned by him to the Santa 

Barbara formation, Waterfall's upper Pico, and Pres 

sler's Santa Barbara horizon and his Kalorama member 

of his Las Posas formation is 2,900 to 3,500 feet thick 

and consists principally of muds tone and shale. Locally, 

lenses of sand and gravel or sandstone and conglomerate 

are at the base and at higher horizons. The lower part 

of the section contains northern and moderate-depth 

species, including Patinopecten caurinus, Thracia trape- 

zoides, and Pandora glacialis, the first two of which occur 

in the Lomita marl and Timms Point silt. In view of the 

recent rinding of sand and gravel at considerable depths 

off the California coast, the occurrence of these species 

locally in sandy and pebbly strata cannot be regarded-as 

conclusive evidence of shallow-water deposition. 62 The 

upper part of the section assigned by Bailey 63 to the 

San Pedro formation, Kew's and Waterfall's Saugus, 

Baton's San Pedro and Hall Canyon formations, and 

Pressler's Las Posas formation and his Long Canyon 

horizon is 3,000 to 3,500 feet thick and consists 

principally of coarse-grained sand and gravel, or sand 

stone and conglomerate, with some sandy silt, silty clay, 

and clay. It contains a shallow-water fauna essentially 

like that of the shallow-water facies of the San Pedro 

sand. Bailey 64 found that toward the north and north 

east, around' the plunging axis of the Ventura anticline 

and Ventura syncline, a tongue of sandstone 300 feet 

M DeLong, J. H. Jr.,The paleonotolgy and stratigraphy of the Pleistocene at Signal 

Hill, Long Beach, Calif.: San Diego Soc. Nat. History Trans., vol. 9, No. 25, pp. 

229-252, 4 figs., 1941. 

" Arnold, Ralph, op. cit. (Calif. Acad. Sci. Mem., vol. 3), p. 56. Hoots, H. W., 

Geology of the eastern part of the Santa Monica Mountains, Los Angeles County. 

Calif.: U. S. Oeol. Survey Prof. Paper 165, p. 120,1931. 

«6 Arnold, Ralph, op. cit., p. 55. 

87 Eaton, J. E., Divisions and duration of the Pleistocene in southern California: 

Am. Assoc. Petroleum Geologists Bull., vol. 12, pp. 126-129, 1928. 

58 Waterfall, L. N.. A contribution to the paleontology of the Fernando group, 

Ventura County, Calif.: California Univ., Dept. Geol. Sci., Bull., vol. 18, table op. 

p. 78, 1929. 

" Pressler, E. D., The Fernando group of the Las Posas-South Mountain district, 

Ventura County, Calif.: idem, pp. 336-338,1929. 

6(1 Bailey. T. L., Lateral change of fauna in the lower Pleistocene: Geol. Soc. Am. 

Bull., vol. 46, pp. 495-497, 1935. 

.el.Bailey, T. L., op. cit., pp. 492-494. 

62 Bailey, T. L., op. cit., p. 494. 

«' Bailey, T. L., op. cit., pp. 490-492. 

«4 Bailey, T. L., op. cit., pp. 494-497. 

below the top of his Santa Barbara formation and 

another tongue of sandstone and conglomerate 550 feet 

lower contain fossils characteristic of his San Pedro 

formation. The close correlation between lithology and 

faunas shows as conclusively as* such matters can be 

shown that the faunas represent different environmental 

associations, and it is reasonably certain that they 

represent different depth associations, as Bailey 65 

thought. 

The 6,000-foot section in the western part of the 

Ventura Basin is considered the essential equivalent 

of 'the lower Pleistocene formations of the San Pedro 

district, but it includes probably younger strata. As 

in the San Pedro district, a moderate-depth facies is 

prevalent in the lower part of the section and a shallow- 

water facies in the upper part. Also as in the San 

Pedro district, the two facies interfinger. Arnold 68 

correlated fossiliferous strata in the shallow-water facies 

of the Ventura Basin with the Palos Verdes sand. 

Baton's objection 87 to that correlation on stratigraphic 

and physiographic grounds is justified. The absence 

of southern species characteristic of the Palos Verdes 

sand cannot be regarded as an objection to Arnold's 

correlation, as they are unknown also in younger 

marine terrace deposits that on stratigraphic and 

physiographic grounds are the probable equivalent of 

the Palos Verdes sand. 

In the Las Posas Hills, on the south border of the 

basin, lower Pleistocene strata unconformably overlap 

the Sespe formation, indicating events similar to those 

in the Palos Verdes Hills, where lower Pleistocene 

deposits unconformably lap onto different parts of the 

Miocene. 

Santa Barbara and Rincon Point. Santa Barbara 

and Rincon Point, between Santa Barbara and Ven 

tura, are located along the north border of the Ventura 

Basin. At both localities the Santa Barbara forma 

tion unconformably overlaps formations older than 

Pliocene (Monterey shale or Sespe formation). Incom 

plete lists of fossils from Santa Barbara, the type 

locality of the Santa Barbara formation, have been 

published by Arnold. 68 At both localities 69 the for 

mation may be divided into a lower Pecten bellus zone 

and an upper Patinopecten caurinus zone. The lower 

zone indicates a shallow-water facies, the, upper zone 

a moderate-depth facies, that is, the age relations of 

the two facies are the opposite of those near Ventura 

and in the San Pedro district. Santa Barbara is the 

type locality of many species found in the lower Pleis 

tocene strata of the San Pedro district, notably Tere- 

bratalia hemphilli, Pnncturella delosi, Bittium rugatum, 

Bittium armillatum, Bittium asperum, Crepidula prin- 

ceps, Barbarqfusus barbarensis, Callicantharus Jortis 

(type locality inland from Santa Barbara), Admete 

gracilior, Cyclocardia occidentalis, and Mercenaria perla- 

minosa. These species occur in the Lomita marl or 

Timms Point silt, or both; some occur also in the San 

Pedro sand. Pecten bellus, based on material from 

Santa Barbara, is not represented in the collections at 

hand but is reported from the Lomita marl. 70 The 

Santa Barbara formation is considered the essential 

equivalent of the lower Pleistocene strata of the San 

65 Bailey, T. L.. OD. cit., pp. 496, 499. 

8« Arnold, Ralph, op. cit., p. 54. 

« Eaton, J. E., op. cit.. p. 124. 

68 Arnold, Ralph, op. cit., p. 52. Geology and oil resources of the Summerland 

district, Santa Barbara County, Calif.: U. S. Geol. Survey Bull. 321, p. 32, 1907. 

For a recent discussion of the Santa Barbara formation see Keen, A. M., and 

Bentson, Herdis, Check list of California Tertiary marine Mollusca: Geol. Soc. Am., 

Special Paper 56, pp. 11-15,1944. 

8«Bailey, T. L., op. cit., p. 494. 

"Grant, U. S., op. cit., p. 71.

Pedro district. The close faunal similarity between 

the Patinopecten caurinus zone and the Lomita, Timms 

Point, and moderate-depth facies of the San Pedro is 

doubtless an expression of a similar moderate-depth 

facies. The Santa Barbara formation is generally 

assigned to the upper Pliocene, or the. lower part to 

the upper Pliocene and the upper part to the lower 

Pleistocene. 

San Francisco 'Peninsula. The upper part of the 

Merced formation of the San Francisco Peninsula 71 is 

generally considered of Pleistocene age. The fauna is 

perhaps too small for a satisfactory comparison with 

the Pliocene .Anarfara-bearing main part of the Merced 

or for a comparison with the Pleistocene faunas of the 

San Pedro district. 

UPPER PLEISTOCENE 

Marino terraces along the California coast are with 

little doubt the equivalent of terraces in the Palos 

Vordos Hills assigned to the upper Pleistocene. Simi 

larity in physiographic history may furnish a basis for 

correlation. Faunal data are likely to be inconclusive. 

Terrace deposits containing southern species were for 

merly and quite naturally correlated with the Palos 

Verdos sand. At least some of the southern species 

characteristic of the Palos Verdes sand are now known 

to have been living in the San Pedro district as early as 

the time when the fourth terrace was formed. Whether 

they wore living still earlier in this district is not known 

now, as a suitable faunal facies has not been found on 

torraoos older than the fourth. The absence of southern 

species in the rock-cliff and tide-pool facies on terraces 

older than the fourth and the presence of a southern 

species (Acanthina lugubris) in that facies on the fourth 

and second terraces suggest, however, that the time 

when southern species lived in this district may have 

begun when the fourth terrace was formed. 

San Diego and nearby localities. Pleistocene terrace 

fossils from San Diego and nearby localities have been 

listed and discussed by Arnold, 72 Berry, 73 Stephens, 74 and 

Webb. 76 Arnold's and Stephens' lists include southern 

species characteristic of the Palos Verdes sand ("Nassa" 

cerritensis, Crassinella branneri, Diplodonta sericata, 

Dosinia ponderosa, and Trachycardium procerum), and 

Arnold pointed out the faunal similarity. Webb 

listed 102 species from localities on the windward 

(western) side of Point Loma, which was an island 78 at 

the time when the terrace was formed. The Point 

Loma fossils arc characteristic of a rock-cliff and tide- 

pool facios, but the fauna is somewhat larger than that 

in the same facios in the Palos Verdes Hills. As in the 

Palos Verdos Hills, the fossils include off-shore species, 

suggested by Webb to have been washed in, and one 

locally extinct northern species (Tegula montereyi), 

found on the fifth to first terraces in the Palos Verdes 

Hills. A southern species (Acanthina lugubris) is listed 

by Berry from a Point Loma locality. None of the 

southern species listed by Arnold and Stephens are 

represented in the Point Loma collections, though the 

deposits are presumably of the same age. The southern 

species arc, however, from localities on the leeward 

'i For the latest list of fossils see Martin/Bruce, The Pliocene of middle and north 

ern California: California Univ. Dept. Qeol. Bull., vol. 9, pp. 229-230,1916. 

" Arnold, Ralph, op. cit. (Calif. Acad. Sci. Mem., vol. 3), pp. 58-64. 

" Berry, S. S., Fossil cliitous of western North America: California Acad. Sci. Proc., 

4th sor., vol. 11, p. 413,1922. 

74 Stephens. Frank, Notes on the marine Pleistocene deposits of San Diego County, 

Calif.: San Diego Soc. Nat. History Trans., vol. 5, No. 16, pp. 245-250,1 flg.. 1929. 

M Wobb, 11. W., Paleontology of the Pleistocene of Point Loma, San Diego County, 

Calif.: Idem, vol. 8. No. 24, pp. 337-348,1937. 

'* Stephens, Frank, op. cit., flg. 1. 


side of the Pleistocene Point Loma island 77 and 

represent a different facies. 

Capistrano Beach. Willett 78 listed and discussed 

recently 153 species of Pleistocene mollusks from Cap 

istrano Beach, between San Diego and Long Beach. 

He estimated that the fossiliferous strata were deposited 

in shallow water at a depth of probably less than 5 

fathoms. Owing to the presence of a few species not 

living hi shallow water in this latitude at the present 

time, he thought that the water was colder than it now 

is. The fossils may, however, represent a mixed asso 

ciation. It is not clear from Willett's description 

whether the fossiliferous strata are terrace deposits, but 

they presumably are. If they are terrace deposits, his 

suggestion that they are of San Pedro age may need 

reconsideration. 

Los Angeles Basin subsurface section. Upper Pleisto 

cene strata in the Los Angeles Basin subsurface section 

are mentioned under the heading "Lower Pleistocene." 

Signal Hill. Arnold 79 described 160 species of mol 

lusks from Pleistocene strata on Signal Hill, or Los 

Cerritos, near Long Beach, and the stratigraphy and 

paleontology of that area have been discussed recently 

by De Long. 80 The fossils described by Arnold and 

listed by De Long include southern species characteris 

tic of the Palos Verdes sand "Nassa" cerritensis, 

Crassinella branneri, Dosinia ponderosa, Chione gnidia, 

Trachycardium procerum, and Trachycardium elatum 

Signal Hill being the type locality of the first two spe 

cies mentioned. The abundance of Amiantis callosa 

also suggests the Palos Verdes sand. Arnold correlated 

these strata with the Palos Verdes, and that correlation 

has been repeated by De Long. Eaton, 81 not realizing 

that the Palos Verdes sand is mildly or moderately de 

formed along the north border of the Palos Verdes Hills, 

objected to the correlation on the grounds that the 

strata on Signal Hill are deformed and was inclined to 

assign them to the lower Pleistocene. On physio 

graphic, stratigraphic, and faunal grounds the strata at 

Signal Hill and the Palos Verdes sand are essential 

equivalents. The Palos Verdes sand and overlying 

nonmarine terrace deposits dip down to the level of the 

Los Angeles Plain at the north border of the Palos Ver 

des Hills, and the strata at Signal Hill have a similar 

physiographic position. Whether the fossiliferous strata 

in the two areas are exactly, synchronous is uncertain, 

for several terraces may have been formed in the rapidly 

emerging Palos Verdes Hills area while one terrace was 

forming in the Newport-Long Beach area. Correla 

tions of individual Pleistocene terrace deposits would 

represent a far greater refinement than, ordinary Qoast 

Range correlations a refinement that may never be 

attained by ordinary methods, 

Play a DelRey. In a recent publication 82 Willett listed 

and discussed a large and interesting fauna of 296 

species of Pleistocene mollusks from a locality on Lin 

coln Avenue, two miles northeast of Playa Del Hey. 

The fossils include the following southern species found 

in the Palos Verdes sand or on the second and fourth 

terraces: Mitra jultoni, "Nassa" cerritensis, Centrifuga 

keana, Nucella biserialis, Forreria belcheri, Pecten 

vogdesi, Crassinella branneri, Crassinella nuculiformis 

" Webb, E. W., op. cit., p. 341. 

'5 Willett, George, Report on Pleistocene molluscan fauna at Capistrano Beach, 

Orange County, Calif.: Southern California Acad. Sci. Bull., vol. 36, pp. 105-107,1938. 

" Arnold, Ralph, op. cit., pp. 30-32. 

so De Long, J. J. Jr., op. cit. 

«' Eaton, J. E., op. cit., p. 135. 

« Willett, George, An upper Pleistocene fauna from the Baldwin Hills, Los Angeles 

County, Calif.: San Diego Soc. Nat. History Trans., vol. 8, No. 30, pp. 379-406 

pis. 25, 26.1937. . .


(" varians"), Mulinia pallida modesta, Trachycardium 

procerum, Trachycardium elatum, and Trigoniocardia 

biangulata. They include also two southern species not 

known to occur in the San Pedro district, Engina strongi 

and " Cancellaria" bullata. According to Willett's inter 

pretation, the fossils lived on a sandy bottom at a depth 

of 10 to 12 fathoms near the mouth of a bay or slough, 

the source of tide-flat and fresh-water species. Ten 

northern and mo derate-depth species, represented by 

more or less fragmentary and much eroded specimens, 

are interpreted by Willett as detrital fossils. Three of 

the northern and moderate-depth species are found in 

the Palos Verdes sand at Arnold's Crawfish George's 

locality. Aside from the occurrence of northern and 

moderate-depth species, the fauna from tne locality 

near Playa Del Rey closely resembles that from Signal 

Hill, and the strata near Playa Del Key are considered 

the essential equivalent of the Palos Verdes sand. At 

the northwest border of the Palos Verdes Hills the first 

terrace dips down to the Los Angeles Plain and extends 

northward along the coast to Playa Del Rey under a 

cover of dune sand. At the northwest border non- 

marine terrace deposits rest directly on the terrace plat 

form, marine deposits being absent. Willett correlated 

the fossiliferous sand with Tieje's Centinela gravel, 83 

which Tieje considered younger than strata he identified 

as the Palos Verdes sand. Inasmuch as Tieje's Centi 

nela gravel and the strata he identified as the Palos 

Verdes sand were not found in the same section, they 

may be of the same age. 

Santa Monica. Marine sand lying on the platform 

(Davis' Dume platf orm) 84 of the lowest terrace along the 

coast of the Santa Monica Mountains contains at a 

locality near the head of Potrero Canyon, 85 2% miles 

from the Santa Monica business district, a fauna like 

that described by "Willett from the locality near Playa 

Del Rey. The southern species Trachycardium pro 

cerum is recorded from the locality near Santa Monica. 

An enormous collection from this locality, gathered dur 

ing a period of many years by Dr. F. C. Clark, is now 

in the Department of Geology of the University of 

California at Los Angeles. According to a communica 

tion from Prof. U. S. Grant, of that institution, the 

collection includes other southern species, namely, 

Engina strongi, Nucella bistrialis, Acanthina lugubris, 

Dosinia ponderosa, and Chione gnidia. The marine 

terrace deposits at the localities near Santa Monica and 

Playa del Rey are doubtless of the same age, but in the 

intervening area the terrace platform is evidently below 

sea level owing to slight deformation. 

Search for marine fossils in deposits lying immediately 

above the rock platform farther inland along the foot 

of the Santa Monica Mountains is justified, for the 

smooth profile of the platform, exposed in street and 

highway cuts, suggests marine planation. 

The fossiliferous gravel in the northwestern part of 

Palms, 86 4}£ miles east-northeast of the Santa Monica 

business district, may be of the same age as the fossil 

iferous sand in Potrero Canyon, but thefaunal evidence 

is meager and inconclusive. 

Localities northwest oj Santa Monica. The southern 

species occurring in late Pleistocene terrace deposits at 

San Diego, Signal Hill, the Palos Verdes Hills, Playa 

83 Tieje, A. J., The Pliocene and Pleistocene history of the Baldwin Hills, Los 

Angeles County, Calif.: Am. Assoc. Petroleum Geologists Bull., vol. 10, p. 510, 1926. 

8 < Davis, W. M., Glacial epochs of the Santa Monica Mountains, Calif.: Oeol. 

Soc. America Bull., vol. 44, pp. 1101-1104, 1933. 

85 Hoots, H. TV., Geology of the eastern part of the Santa Monica Mountains, Los 

Angeles County, Calif.: TJ. S. Geol. Survey Prof. Paper 165, pp. 121-122, 1931. 

»Idem, p. 122. 

Del Rey, and Santa Monica have not been found at lo 

calities farther north. Grant 87 concluded that mol- 

lusks from terraces at altitudes of 500 and 700 feet in 

the Ventura district indicate a temperature environ 

ment essentially like the present environment at Ven 

tura. Mollusks from the thin veneer V)f marine sand 

lying on the platform of the lowest terrace at Carpen 

teria, 10 miles east of Santa Barbara, are interpreted by 

Grant and Strong 88 as indicating a marine temperature 

slightly cooler than the present one along the coast of 

Santa Barbara County. The nonmarine cover overly 

ing the marine sand contains fossil vertebrates and 

plants. It may be essentially contemporaneous with 

the marine deposits or may be considerably younger. 

According to Oldroyd and Grant, 89 mollusks from 

marine deposits on the lowest terrace near Goleta, 10 

miles west of Santa Barbara, including the northern 

and moderate-depth Fusitriton oregonensis, indicate a 

temperature probably cooler than the present one. The 

age relations of the terrace deposits at these localities, 

and at localities still farther north, to the Palos Verdes 

sand appear to be indeterminable. Despite the differ 

ence in f aunal association they may be of the same age, _ 

or they may be older or younger. 

PLEISTOCENE TO RECENT SERIES 

NONMARINE TERRACE COVER 

STRATIGRAPHY AND MTHOLOGY 

Poorly sorted or unsorted rudely stratified sand, rub 

ble, and gravel overlie marine deposits on terraces in the 

Palos Verdes Hills or in their absence lie immediately 

on the platform. These- deposits are designated the 

nonmarine terrace cover. They represent cliff talus 

rubble, stream fan and channel material, and rill and 

slope wash. This debris was derived from the cliff 

backing a terrace and the highland farther inland, and 

it accumulated after emergence of the terrace. The 

origin and physiographic aspects of the nonmarine cover 

of terraces along the California coast were first clearly 

described by Davis 90 in his account of the terraces along 

the Santa Monica Mountains, the next highland area 

up the coast from the Palos Verdes Hills. Its physio 

graphic aspects in the Palos Verdes Hills are discussed 

under the heading "Physiography," page 113. 

Deposits of the nonmarine cover are steeply banked 

against the cliff at the rear of a terrace, and they slope 

toward the seaward edge with decreasing dip and thick 

ness. Toward the rear of a terrace their thickness is as 

much as 100 feet, but an exposed thickness greater than 

50 feet is exceptional. As shown in figure 15, the cover 

may extend uninterruptedly across more than one ter 

race and effectively conceal the sea cliff between 

successive platforms. 

The bulk of the cover on a terrace accumulated soon 

after emergence of the terrace. According to the age 

classification adopted for the terraces, the cover im 

mediately overlying marine deposits or resting on the 

platform is of upper Pleistocene age. Ever since emer 

gence of the terrace accumulation of nonmarine debris 

has continued, however, at least at the rear of a 

terrace, and at places deposits of markedly different 

w Grant, U. S., in Putnam, W. C., Geomorphology of the Venjara region, Calif.: 

Geol. Soc. Am. Bull., vol. 53, pp. 699-700, 1942. 

88 Grant, U. S., and Strong,,A. M., Fossil mollusks fron the vertebrate-bearing as 

phalt deposits at Carpenteria, Calif.: Southern California Acad. Sci. Bull., vol. 33, 

pp. 7-11,1934. 

ss Oldroyd, T. S., and Grant, U. S., IV, A Pleistocene molluscan fauna from near 

Goleta, Santa Barbara County, Calif.: Nautilus, vol. 44, pp. 91-94, 1931. 

90 Davis, W. Mi, Glacial epochs of the Santa Monica Mountains, Calif.: Geol. Soc. 

America Bull., vol. 44, pp. 1055-1056,1058-1061, figs. 5, 6, 1933.

age extend over an entire terrace. There is, there 

fore, every gradation between Pleistocene deposits 

and deposits still accumulating. On the other hand, 

the highest terraces have lost much or virtually all 

of their original cover through erosion. 

The statement that the nonmarine cover on a terrace 

accumulated after emergence of the terrace needs the 

following qualification. In the event that talus rub 

ble accumulated against the cliff formed by marine 

planation, and was not removed prior to emergence, 

that part of the cover antedates emergence and is con 

temporaneous with marine deposits on the terrace. In 

deed, a mixture of contemporaneous marine deposits 

and talus rubble was observed at several localities, and 

marine constituents were found in talus rubble. 

The best exposures of the nonmarine cover are along 

the present sea cliff and in highway cuts. It forms 

steep or vertical slopes that are rilled and fluted. It 

is generally characterized by a reddish-brown color, 

which is due to a coating of iron oxide on sand grains 

and larger constituents, the result of oxidation of iron 

compounds. Soil formed by the cover is also reddish- 

brown. It resembles soil of similar color formed on 

basaltic rocks but is more sandy than residual basaltic 

soil. The nonnmrine terrace cover is shown 011 the 

geologic maps (pis. 1, 14, 21) at localities where, it .is 

thick enough and of sufficient extent to completely 

conceal underlying formations! 

The greatest observed thickness of nonmarine 

terrace cover is exposed in the present sea cliff along 

Portuguese Bend at and near locality 99, where it is 

about 100 feet thick. The basal foot or two, overlying 

marine fossilifcrous gravel and shingle a foot or two 

thick/ consists of small stones, pebbles, and sand. The 

remainder is made up of reddish-brown sand that in 

cludes lenses of poorly rounded and angular stones. 

. Banking of rudely stratified rubble and sand against 

the cliff at the rear of the fourth terrace is well shown 

at the south end of the cut at Bluff Cove, on Palos 

Verdes Drive West. It is also shown at the rear of 

the second terrace in a highway cut north of Point 

Fermin, near locality 94. At that locality about 25 

feet of rubble, decreasing in coarseness upward, is 

banked against the face of the cliff, which has a slope 

of 60°. The upper surface of the rubble dips 20°. 

The rubble is overlain by 15 feet of reddish-brown 

sand. A worn fragment of a marine snail (Olivella) 

was found in the rubble 10 feet from the face of the 

cliff. 

Examples of a mixture of talus rubble and contem 

poraneous marine deposits toward the rear of a terrace 

are described under the heading "Marine terrace de 

posits," pages 53-55. Marine material derived from 

earlier terraces or more probably hurled by storm waves 

far above hightide line 'was observed at the rear of the 

second terrace at the locality near Point Fermin just 

described; on the west side of Gaffey Street, near 

Thirty-ninth (locality 95), a few worn and broken 

shells were found in rubble 5 to 6 feet thick banked 

against the cliff at the rear of the terrace; and at lo 

cality 97, on the north side of Thirty-seventh Street, 

near Averill, worn and broken shells and echinoid 

spines were collected from talus rubble 10 feet thick. 

The rubble lies against the face of the cliff, which has 

a slope of 60°. 

FOSSILS 

Marino fossils are rare in the nonmarine terrace 

cover and are thought to be extraneous. They repre 

107 

sent rock-cliff and tide-pool species that are abundant 

in the marine terrace deposits. Remains of land mam 

mals were found in the nonmarine cover of the first 

terrace at two localities. Horse molar teeth fragments 

were found repeatedly at a locality on the north limb 

of the Gaffey anticline, 2,000 feet southeast of the inter 

section of Palos Verdes Drive East and Western Avenue. 

A bison foot bone, identified by Dr. Chester Stock, 

was collected in San Pedro, on the north side of Third 

Street 150 feet west of Pacific, where the nonmarine 

cover rests directly on the platform of Miocene mud- 

stone. Ground sloth remains from the nonmarine 

cover on the first terrace at Second and Beacon Streets 

have been described as Megalonyx milleri. 91 . Mr. 

M. Stockton, formerly superintendent of the Dicalite Co., 

reports that an' elephant tusk and camel bone were 

found in a lens of gravel and rubble exposed in the 

workings of that company. 

PLEISTOCENE (?) SERIES 

STREAM TERRACE GRAVEL 

The bench on the east side of Gaffey Street, 2,000 

feet north of the intersection of Harbor Boulevard and 

Pacific Avenue, is underlain by gravel composed prin 

cipally of flat schist pebbles 1 to 3 inches long. This 

material is considered as stream gravel deposited by 

the stream draining the schist area, the present George 

F Canyon. The contact between the gravel and the 

nonmarine cover on the first terrace is not exposed. The 

gravel probably truncates the cover, however, and is 

therefore probably younger than the cover. The ad 

joining higher bench is probably a stream terrace, but 

no stream terrace deposits were recognized on it. The 

southeastward-sloping bench farther inland on the 

north side of George F Canyon may also represent a 

stream terrace, but the strata forming the bench are not 

exposed. 

Stream terrace gravel forms a little bench along the 

lower course of Agua Magna Canyon about 30 feet 

above the stream floor. The gravel consists mostly of 

poorly rounded and angular pieces of cherty shale and 

sandstone, one sandstone slab being about 15 feet long. 

RECENT SERIES 

DUNE SAND 

The strip of dune sand extending along the coast 

southward from Playa'Del Rey, 12 miles north of 

Malaga'Cove, overlaps the northwest end of the Palos 

Verdes Hills. The limits of the dune sand in the 

Palos Verdes Hills are uncertain, as it grades into the 

first terrace nonmarine cover, which underlies it and 

furnished presumably some, or most, of the material for 

it. The dune sand has a cover of vegetation, even in 

areas where the natural vegetation is not greatly dis 

turbed, and is no longer actively moving except near 

the edge of the sea cliff, where vegetation is scanty. 

E. F. Walker, of the Southwest Museum, has found 

three human culture levels in' the dune sand at Malaga 

Cove and a fourth level in the uppermost 3 feet of the 

underlying nonmarine terrrace cover. 92 At that locality 

the nonmarine cover of the first terrace, 25 feet thick, 

lies directly on Miocene and Pliocene formations and is 

81 Lyon, O. M.. Megalo-nyx milleri, a new Pleistocene ground sloth from southern 

California: San Diego Soc. Nat. History Trans., vol. 9, No. 6, pp. 15-30, pi. 1, flgs. 

1-7, 1938. 

M Walker, E. F., Sequence of prehistoric material culture at Malaga Cove, Calif.: 

Masterkey, vol. 11, No. 6, pp. 210-214, 2 flgs., 1937.

108 

overlain by 25 to 30 feet of dune sand (fig. 7). The 

uppermost 3 feet of the nonmarine terrace cover con 

taining the oldest culture is contaminated with much 

black organic material. The first terrace is considered 

of late Pleistocene age, and the cover on it at this 

locality, at a considerable distance from the highlands 

to the south that furnished the debris, is also considered 

late Pleistocene. As shown in figure 7 and plate 26, the 

terrace is arched over the strongly deformed Tertiary 

formations and slopes toward the highland source of 

the nonmarine cover. The deposition of the cover ante 

dates, of course, deformation of the terrace and its cover. 

If the human inhabitants responsible for the lowest cul 

ture level lived during the deposition of the uppermost 

3 feet of the cover, that culture represents a considerable 

antiquity late Pleistocene according to the age classifica 

tion adopted in the present report. If, on the contrary, 

the lowest culture represents human occupancy after 

deposition of the cover but before deposition of the 

dune sand, its antiquity is correspondingly less. Dur 

ing a field conference at the site in the spring of 1938 

Mr. Walker and Dr. Hildegarde Howard, of the Los 

Angeles Museum, reported that the material collected 

from this culture level includes mineralized bones'of the 

extinct diving goose Chendytes lawi, which occurs in the 

Palos Verdes sand in San Pedro, and nonmineralized 

bones of species of birds and other animals now living. 

Whether the remains of the extinct goose at Malaga 

Cove represent an animal that was a contemporary of 

the human inhabitants or represent older material con 

centrated at the culture site by natural or human 

agencies is not known. In view of the occurrence of 

nonmineralized remains of species of animals . now 

liying, however, the extinct goose is probably older than 

the human inhabitants. 

The other three culture levels are in the dune sand. 

Glass trade beads were found a't the top of the up 

permost level, about 5 feet below the top of the dune 

sand. 

The dune sand is considered of Recent age. All except 

the uppermost part antedates the historic period. The 

age of the remainder is a matter of inference based on 

the succession of geologic events and the uncertain 

dating of the Pleistocene record. The present inactivity 

of the dunes suggests that they were formed during a 

period when the present protective cover of vegetation 

was lacking. Whether the change from actively moving 

dunes to inactive dunes is to be correlated with a change 

from greater to less aridity or is to be correlated with 

unknown changes resulting in 'cutting off of the supply 

of sand is a matter that deserves consideration in any 

attempt to work out a succession of events in the post- 

Pleistocene history of the Pacific coast and its human 

inhabitants. The three culture levels in the dune sand 

at Malaga Cove indicate a considerable time span. 

ALLUVIUM 

Alluvium, presumably of Recent age, was mapped 

along the lower course of some streams, especially 

George F Canyon and the stream that flowed in the 

valley followed by Gaffey Street. Narrow bands of 

alluvium, too narrow to be mapped, are found also along 

many streams at the north border of the hills and 

elsewhere. As explained under the heading "Physiog 

raphy," page 117, at the north border of the hills the 

nomnarine cover lying on the first terrace does not dip 

under modern alluvium but continues as the upper part 

of the older alluvium of the Los Angeles -Plain. 

BASALTIC ROCKS OF MIOCENE AGE 

Intrusive basaltic rocks occur in the lower and middle 

parts of the Altamira shale member of the Monterey 

shale but are not known to penetrate younger units. 

Most of the igneous bodies are sills, ranging in thickness 

from a foot to several hundred feet, or irregular bodies 

more or less concordant to the bedding. A thick sill 

may be seen on the south limb of the Bluff Cove anti 

cline in a cut. on Palos Verdes Drive West and another 

on the Miraleste anticline in cuts on Palos Verdes Drive 

East. At some localities tongues of basalt extend into 

the sedimentary rocks, as shown on plate 6, C, a view 

near Point Vicente. 

The underlying and overlying sedimentary rocks are 

generally altered in a zone of variable thickness ranging 

from less than a foot to several feet. Cherty shale is 

altered to more dense nearly black chert containing 

scattered crystals of ankerite, and altered limestone is 

dark and hard. At many places both basalt and sedi 

mentary rocks are brecciated, irregular tongues of basalt 

are numerous, the basalt contains inclusions of cherty 

shale and limestone, the sedimentary rocks contain 

inclusions of basalt, and limestone dikes penetrate 

brecciated basalt. One of these localities, in the sea cliff 

northward from Point Vicente, was described by 

Macdpnald,93 who concluded that the relations indicate 

intrusion near the sea floor under a thin cover of Miocene 

sediments. Perhaps a better example of intrusion into 

a thin cover of nearly unconsolidated sediments is 

afforded by the reefs exposed at low tide 0.35 mile 

northwest of Whites Point. At that locality masses of 

basalt are embedded in a limy and sandy matrix con 

taining poorly preserved marine mollusks, Foraminif era, 

and small fragments of basalt. Some of the basalt may 

have reached the surface in the form of a submarine flow. 

The b,asalt is generally much weathered and altered. 

The weathered rock is dark brown and soft and at 

some localities is powdery and characterized by bright 

hues of yellow, pink, and lavender. The fresh rock is 

dark gray to black. A fresh specimen from a highway 

cut 0.6 mile east of Point Vicente is an almost black 

basalt composed principally of labradorite and augite, 

the larger phenocrysts being labradorite. Magnetite 

is relatively rare, pyrite is common. A thin film of 

opal lines cavities and fills some of the smaller inter 

stices. Dolomite fills some of the larger cavities within 

the opal film. Another specimen collected from mate 

rial excavated in the highway cut at Bluff Cove is a 

basalt or diabase. The rock is greenish gray, owing to 

a large amount of interstitial cmoritic material. Lab 

radorite and .augite form a more nearly equigranular 

texture than in the specimen just described, but some 

of the larger augite crystals show ophitic intergrowth 

with the labradorite. Pyrite is present, but magne 

tite is relatively rare. Interstitial opal and cavity- 

filling dolomite are less abundant than in the other 

specimen. Part of the chloritic material shows indices 

of refraction and a birefringence too high for common 

chloritic minerals and may represent an iron-rich vari 

ety of chlorite. The petrology of the basalt immedi 

ately north of Point Vicente was described by Mac- 

donald. 94 

The greatly weathered igneous rock resting on the 

schist or close to the schist in the main schist area in- 

« Macdonald, Q. A., An intrusive peperite at San Pedro Hill, Calif.: California 

Univ., Dept. Geol. Sci., Bull., vol. 24, pp. 329-338, 6 flgs., 1939. 

« Macdonald, G. A., op. cit., pp. 332-334.

eludes volcanic agglomerate or breccia that appears to 

be in part of andesitic composition. 

STRUCTURE 

STRUCTURAL HISTORY 

Miocene. The pre-Miocene and early Miocene 

structural history of the Palos Verdes Hills is unknown 

except insofar as it is inferred from the strati graphic 

record and the history of nearby regions. 95 The ab 

sence of Cretaceous, early Tertiary, and early Miocene 

formations suggests that during those periods the 

present Palos Verdes Hills were part of an extensive 

schist highland. The northward overlap of middle 

Miocene deposits indicates progressive subsidence of 

the schist highland during Miocene tune. The differ 

ent members of the Monterey shale in the Palos Verdes 

Hills, of late middle Miocene to late upper Miocene age, 

are conformable to each other. In the Santa Monica 

Mountains early upper Miocene deposits (lower part 

of Modelo formation, or Monterey shale of some geo 

logists) rest with marked discordance on middle Mio 

cene deposits (Tppanga formation), aside from, local 

exceptions. 08 This period of deformation has not been 

recognized in the Palos Verdes Hills. 97 In the Point 

Fennin area the upper part of the Altamira shale mem 

ber of the Monterey, which, is correlated with the 

lower part of the Modelo of the Santa Monica Moun 

tains contains coarse-grained schist debris. Strata of 

that age are not known to rest on the schist in the Palos 

Verdes Hills. The decrease in coarseness and thick 

ness of the schist debris northward from Point Fermin 

indicates derivation from a now submerged schist area 

farther south. The great quantity of schist detritus, 

which is less abundant in underlying strata in the 

Point Fermin area, suggests deformation of the schist 

area during early upper Miocene time. These schist- 

bearing sediments are of the same age as strata resting 

on schist in the Playa Del Rey and adjoining oil fields. 

The middle Miocene San Onofre-like schist breccia at 

Bluff Cove may represent debris derived from a local 

schist area. 

Late Pliocene deformation. At Malaga Cove the 

lower Pliocene Repetto siltstone disconformably overlies 

the upper Miocene Malaga mud stone member of the 

Montorey (pi. 10, A; fig. 7). Elsewhere in the Palos 

Vordes Hills the relations between those two units are 

uncertain, owing to difficulty in distinguishing bedding 

in meager exposures of massive mud stone and equally 

massive siltstone. Upper Pliocene deposits, represented 

in the Los Angeles Basin by the Pico formation, are 

not recognized anywhere in the Palos Verdes Hills. 

Wherever the relations are clearly shown, the lower 

Pleistocene strata, consisting of the Lomita marl, Timms 

Point silt and San Pedro sand, rest unconformably on 

underlying formations. This relation is particularly 

well shown in the combined surface and subsurface 

(Whites Point tunnel) structure section E E' of 

plate 1. At the only localities where the lower Pleisto 

cene strata rest on the lower Pliocene Repetto, localities 

in the western part of the Gaffey anticline and Gaffey 

" .For a discussion of the pro-Miocene and Miocene history of the Los Angeles 

Basin and its borders see Reed, R. D., and Hollister, J. S., Structural evolution of 

southern California, pp. 115-124, 133-135, Am. Assoc. Petroleum Geologists, Tulsa, 

Okla., 1930. 

'»Hoots, H. W., Geology of eastern part of Santa Monica Mountains, Los Angeles 

County, Calif.:U. S. Geol. Survey Prof. Paper 165, pi. 17, (structural sections), 1931 

w Rood and Hollister (op. cit., fig. 44. p. 119) show an unconformity in the Palos 

v Vordes Hills at the base of the Valmonte diatomite member of the Monterey and 

correlate the Valmonte with the lower part of the Modelo formation of the Santa 

Monica Mountains. .This unconformity was not recognized during the field work 

on which the present report is based, and the Valmonte is considered younger than 

the lower part of the Modelo of the Santa Monica Mountains 

STRUCTURE 109 

syncline, the relations are uncertain, owing to the 

massive character of the Repetto. At Malaga Cove 

sand doubtfully identified as the San Pedro unconform 

ably overlies 'the upper Miocene Malaga mudstone. 

The well-defined relations at Malaga Cove show 

that no deformation took place there before deposition 

of the lower Pliocene Repetto siltstone. The equally 

well-defined relations of structure section E E' show 

that strong deformation took place in the northeastern 

part of the hills before deposition of the lower Pleisto 

cene formations. In view of the small size of the area 

involved, these relations are considered representative 

of the northern part of the hills. It follows then that 

the deformation took place during late Pliocene time. 

This was the period of strongest deformation in the 

known geologic history of the Palos Verdes Hills, at 

least in the northern part of the hills and also by infer 

ence elsewhere in the hills where lower Pleistocene 

strata are not now present. 

The subsurface section in the Wilmington oil field.98 

a few miles east of the Palos Verdes Hills, also shows a 

period of deformation during late Pliocene time. 

Middle Pleistocene deformation. The lower Pleisto 

cene formations are deformed and are overlain uncon 

formably by the upper Pleistocene Palos Verdes sand 

or by slightly older marine terrace deposits also con 

sidered of upper Pleistocene age. In San Pedro the 

lower Pleistocene strata are tilted northeastward at 

angles ranging from a degree or two to 22° (pi. 15, 

A, B). Inasmuch as the dip decreases away from the 

hills, even in single exposures as on Second Street and 

on the destroyed Deadman Island, and inasmuch as no 

folds are known in the area covered by Pleistocene 

strata in San Pedro, the deformation in that area is 

regarded as the result .of uplift of the hills. Indeed, 

an undetermined part of the relatively steep dips 

adjoining and close to the Miocene basement represents 

probably depositional dips. Along the Gaffey anticline 

and syncline, however, the lower Pleistocene strata are 

folded (sections D D', E E', pi. 1) and along the 

north border of the hills farther west they are strongly 

deformed (pi. 20; fig. 13; pi. 1, section B B'}. 

According to the age assignments of the formations 

above and below the unconformity, this deformation 

is middle Pleistocene. It is thought to antedate the 

oldest marine terraces, which are assigned to the upper 

Pleistocene. 

The middle Pleistocene deformation in the Palos 

Verdes Hills, which is of the same age as strong defor 

mation in the Ventura Basin and presumably elsewhere 

in the Coast Ranges, has been emphasized in recent 

discussions of Coast Range deformation, 99 whereas the 

stronger pre-Pleistocene, that is, late Pliocene, deforma 

tion is not considered in those discussions. 

Late Pleistocene and Recent deformation. In San 

Pedro the upper Pleistocene Palos Verdes sand, con 

stituting the marine deposits on the youngest terrace, 

and the overlying nonmarine terrace cover have the 

expectable gentle seaward dip. Along the Gaffey anti 

cline and Gaffey syncline those deposits are gently 

folded (pi. 1, sections D Df , E E'}, and along the 

north border of the hills west of the Gaffey anticline 

they are moderately deformed, dipping northward at 

angles of as much as 26° (fig. 13; pi. 1, sections B B', 

« Bartosh. E. J., Wilmington oil field. Los Angeles County, Calif.: Am. Assoc. 

Petroleum Geologists Bull., vol. 22, p. 1056, fig. 3,1938. 

" Stille, Hans, Der derzeitige tektonische Erdzustand: Preuss. Akad Wiss., Phys.- 

math. Kl., Sitzungsber., 1935, pp. 205-206. (Translation under title "Present tectonic 

state of the earth": Am. Assoc. Petroleum Geologists Bull., vol. 20, p. 868, 1936.) 

Reed, R. D., and Hollister, J. S., op. cit., p. 49, 1936.

110 


C C'}\ that is, the relative degree of deformation in 

those areas is the same as for the lower Pleistocene for 

mations. The post-Palos Verdes deformation along the 

north border of the hills is of late Pleistocene or Recent 

age, more probably the former. Elsewhere in the Palos 

Verdes Hills deformation in the form of successive epi 

sodes of uplift took place during late Pleistocene time. 

A later, presumably not only Recent but quite mod 

ern, episode of post-Palos Verdes deformation is prob 

ably represented by slight deformation of alluvium 

along the crest of the Gaffey anticline. In fact, the 

anticline may still be growing. 

REGIONAL RELATIONS 

The Palos Verdes Hills form a conspicuous uplift at 

the south border of the Los Angeles Basin. In the 

schist basement and also in the immediately overlying 

sediments the boundary between the hills and the basin 

is thought to be marked by a fault. A fault at that 

boundary is generally shown on small-scale structural 

maps, 1 and a fault zone is shown on the fault map of 

California issued in 1922 by the Seismological Society of 

America. The inferred subsurface fault has been desig 

nated the San Pedro fault. 2 A major structural feature 

corresponding to the .inferred subsurface fault has not 

been found at the surface. The north border of the hills 

is, nevertheless, the most mobile region in the entire 

area. Late Pliocene deformation was strong in that 

region, middle Pleistocene deformation was stronger 

there than in other parts of the hills, and late Pleistocene 

and Recent deformation other than uplift are recognized 

only in that region. Furthermore, wells drilled along 

the north border of the hills encounter sheared and 

steeply dipping Pliocene and Miocene strata. Two 

wells in that area are reported to have penetrated 

Miocene strata, then Pliocene, and then Miocene again, 

indicating an anticlinal fold overturned northward or 

a reverse fault dipping steeply southward. 

If the inferred fault along the north border of the hills 

is a structural reality, it is presumably not pre-Miocene. 

The Miocene section in the Palos Verdes Hills is some 

what thinner than that in the part of the Los Angeles 

Basin between the hills and the syncline immediately 

south of the Newport-Inglewood uplift but includes 

strata older than any known in that part of the basin. 

The northward overlap of successively younger parts of 

the Miocene on the schist basement in the Palos Verdes 

Hills continues to the Torrance oil field, where upper 

Miocene strata rest on the schist. 3 Also in the El 

Segundo and Playa Del Rey oil fields, farther north, 

upper Miocene overlies schist. (For location of areas 

mentioned see fig. 1.) Middle Miocene strata may be 

present in the syncline between the Torrance and El 

Segundo anticlines, but that possible exception does not 

affect the comparative history of the Palos Verdes. Hills 

and the adjoining part of the Los Angeles Basin. Nor 

is it probable that the inferred fault is of pre-Pliocene 

age, as has been claimed. 4 The stratigraphic data on 

1 Ferguson, R. N., and Willis, C. O., Dynamics of oil-field structure in southern 

California: Am. Assoc. Petroleum Geologist Bull., vol. 8, fig. 1 (p. 578), 1924. Clark, 

B. L., Tectonics of the Coast Ranges of middle California: Qeol. Soc. America 

Bull., vol. 41, pi. 16 (op. p. 770), 1930 [1931J; Age of primary faulting in the Coast 

Ranges of California: Jour. Geology, vol. 40, p. 400, fig. 1, 1932; Folding of the Cali 

fornia Coast Range type illustrated by a series of experiments: Idem, vol. 45, fig. 

16 (pp. 314-315), 1937. Willis. Bailey, San Andreas rift in southwestern California: 

Jour. Geology, vol. 46, fig. 1 (p. 1018), 1938. 

* The San Pedro fault zone of Willis (op. cit.) is a different inferred subsurface fea 

ture generally designated the Newport-Inglewood fault or fault zone. 


Petroleum Geologists Bull., vol. 20), fig. 3 (p. 140), 1936. 

< Clark, B. L., Age of primary faulting in the Coast Ranges of California: Jour.' 

Geology, vol. 40, p. 400, 1932. 

which that opinion was based are erroneous. Though 

the lower Pliocene section in the Palos Verdes Hills is 

much thinner than in che adjoining part of the basin, it 

includes equivalents of a considerable part of the thick 

basin section and consists of deposits of deep-water 

facies. The inferred fault does not antedate presum 

ably the late Pliocene deformation. 

The relatively straight steep submarine slope parallel 

to the trend of the Palos Verdes Hills 2 to 4 miles off the 

south coast, Shepard and Emery's San Pedro escarp 

ment, 5 suggests a fault, as indicated on some of the 

small-scale structural maps already cited. The in 

ferred fault is more hypothetical than that just described. 


In general the greater part of the Palos Verdes Hills 

is characterized by relatively simple structure, the 

major folds being broad and gentle, but in certain areas 

the entire north border, the area between western San 

Pedro and Palos Verdes Drive East, and a small area on 

the south coast at Whites Point and nearby the struc 

ture is complex, the folds being narrow, steep, and 

locally overturned. Apparently simplicity in some 

areas may be due to lack of adequate exposures. In 

areas of generally simple structure sea-cliff and highway 

exposures show an abrupt change to local complex 

structure. These .local exceptions do not affect, how 

ever, the broad classification of areas of simple and 

complex structure. 

Only a few of the strike and dip measurements de 

termined and plotted in the field are shown on the 

geologic map (pi. 1). It would be confusing rather than 

helpful to show a great number of these measurements 

on a map of the scale of plate 1. Local details could not 

be shown on a map of any scale in areas where the 

structure is markedly different at different levels in a 

vertical plane at a single exposure. That there are 

many such areas is apparent in even a casual examina 

tion of highway cuts' and natural exposures. The folds 

shown on plate 1 were selected to represent the trend of 

folds considered of more than local extent. Some of 

them may be misinterpreted, and folds of equal extent 

may be omitted. 

Owing to the failure to find persistent recognizable 

lithologic units through hundreds of feet of Miocene 

strata, only a few faults are shown on plate 1. Faults 

and brecciated zones were recognized at numerous other 

localities in both surface exposures and the Whites 

Point tunnel. At places the displacement at those 

localities is demonstrably slight, at other places it may 

be scores or hundreds of feet. 

. The folds and the few faults shown on plate 1 have a 

general northwestward trend roughly parallel to the 

trend of the hills. In two areas, however, the trend is 

notably different. Near the north border in the north 

western part of the hills the structural features trend 

westward, in the Bluff Cove and adjoining areas they 

trend southwestward. The structurally highest anti 

clines are in the east-central part and at Bluff Cove. In 

both areas the general direction of plunge is eastward. 

NORTH BORDER OF HILLS 

The north border of the hills includes the entire area 

of lower Pleistocene deposits with the exception of the 

« Shepard, F. P., and Emery, K. O., Submarine topography ofl the California coast: 

Geol. Soc. America Special Papers 31, chart 1,1941.-

San Pedro district, where those strata dip northeast 

ward, at a rate decreasing in that direction. 

The GaiTey anticline and accompanying Gaffey syn- 

cline are the most extensive structural features along 

the north, border of the hills. They have a northwest 

ward trend parallel to the border and plunge south 

eastward. The relatively wide band of the Malaga 

mudstone member of the Monterey along Agua Magna 

Canyon suggests that the anticline and syncline may 

emerge in that area. They evidently do not affect, 

however, the nonmarme terrace cover between Agua 

Magna Canyon and Bent Spring Canyon. Eastward 

from Bent Spring Canyon the Palos Verdes sand and 

overlying nonmarine cover are gently folded, the lower 

Pleistocene Lomita marl and San Pedro sand are more 

strongly folded, and the Malaga mudstone and presum 

ably olso the Rcpetto siltstone are still more strongly 

folded, as shown in structure sections D D' and-E1 E' 

of plate 1; that is, the anticline and syncline are per 

sistent structural features, and deformation took place 

along them during each period of deformation. In the 

Whites Point tunnel and at nearby outcrop localities 

the Malaga mudstone is complexly folded and probably 

faulted in the core of the anticline, more complexly then 

can be shown on structure section E E' of plate 1. 

Owing to inadequate exposures it is not known whether 

the structure is complex in the area represented by 

structure section D D'. On Western Avenue a minor 

thrust fault along the contact between lower Pleistocene 

and Miocene formations on the south lunb of the anti 

cline displaces the base of the nonmarine cover on the 

lowest terrace (pi. 17, B). At that locality the lower 

Pleistocene strata appear to dip more steeply than the 

Miocene, owing presumably to truncation of a minor 

fold in the Miocene strata. Between Palos Verdes 

Drive East and Gaffey Street the surface slope, formed 

by the nonmarine cover, is virtually a dip slope. East 

of Gaffey Street the surface slope does not agree with 

the dip of the youngest formations or there are two 

anticlinal bulges, one closer to the border of the hills 

than the crest of the Gaffey anticline farther west. 

During construction of the part of the Whites Point 

tunnel where the Malaga mudstone was penetrated 

along the Gaffey anticline, particularly on the south 

limb of the anticline, the floor of the tunnel buckled and 

less marked movement took place on the walls and roof. 

The Malaga mudstone is perhaps the most plastic for- 

.mation encountered in the tunnel, and the squeezing 

ground may have resulted from plastic flow due to 

weight of the overburden. Release of elastically stored 

energy resulting from deformation along the anticline 

may have been a contributing or major factor. 

West of the Gaffey anticline and Gaffey syncline the 

Tertiary and Pleistocene formations are strongly de 

formed. The Miocene and lower Pliocene strata are 

strongly folded, the lower Pleistocene strata dip north 

eastward at angles ranging from a few degrees to almost 

vertical, the upper Pleistocene strata dip in the same 

direction at angles of as much as 26°, and faults affect 

the youngest formations (pi. 1, sections B B', C C'; 

pi. 20, fig. 13). In most of the area between Hawthorne 

Avenue and the strip of dune sand a fault or series of 

closely spaced faults dips steeply northward ,(pl- 1, sec. 

B B'; fig. 13). The vertical displacement, down to 

the north, is the same as in the hypothetical subsurface 

fault bordering the hills. The surface fault zone is, 

however, a minor feature and may not be directly con 

nected with the hypothetical major subsurface fault. 

In the sixth and ninth ravines west of Hawthorne 

STRUCTURE 111 

Avenue the Malaga mudstone rests on sand and gravel 

of the nonmarine terrace cover along a virtually horizon 

tal contact north of the falls that mark the fault, as 

though the mudstone were thrust northward over the 

terrace cover. The relations at those localities are due 

presumably to flowage of water-soaked mudstone. The 

upper part of the mudstone south of the fault is lubrica 

ted by water that seeps through the overlying sand and 

moves northward along the contact between sand and 

mudstone. 

Strong deformation of Miocene and lower Pliocene 

formations along the north border of the hills is well 

shown in the sea cliff at Malaga Cove (pis. 10, A, 11, 12; 

fig. 7). At that locality, however, doubtfully identified 

lower Pleistocene strata and the nonmarine cover on the 

lowest terrace are mildly deformed. Two steeply dip 

ping faults are visible in the Miocene strata, and a third 

fault is probably concealed. Farther north three 

minor faults, two of which are shown on plate 12, A, B, 

displace the base of the San Pedro (?) sand 10 to 15 feet 

vertically and extend down'into the Malaga mudstone 

along bedding planes dipping 75° northward. The 

hanging wall is displaced upward, but the relative 

relations of 'hanging wall and footwall may be due to 

horizontal or oblique movement. 

NORTHWESTERN PART OF HILLS 

The closely spaced steeply tilted folds characteristic 

of the northwest border of the hills extend farther south 

into' the Malaga Cove and Valmonte residential dis 

tricts (pi. 1, sec. B B'). The folds have a westward 

trend, and plunge eastward as they approach the south 

eastward-trending border of the hills. A fault extend 

ing to the border of the hills may separate these west 

ward-trending folds from the northeastward-trending 

and northwestward-tending folds farther south. 

Until persistent lithologic units are found in the Alta- 

mira shale member of the Monterey it would be diffi 

cult, however, to establish a fault on other than 

doubtful physiographic grounds. 

BLUFF COVE AND NEARBY AREAS 

At Bluff Cove and nearby .the structural features 

have a southwestward trend, swinging more toward the 

west. The northeastward-plunging Bluff Cove anti 

cline and the basin-shaped syncline farther inland, in 

which the Valmonte diatomite member of the Mon 

terey shale is mapped, are examples. The syncline just 

mentioned is part of a general synclinal area trending 

almost at right angles to the trend of the hills and bend 

ing westward near the coast.- Faults are recognized 

or inferred to be present in the sea cliff in the Bluff Cove 

(pi. 1, sec. A-A'} and Flatrock Point areas but were not 

detected inland. The minor isoclinal anticline shown 

in figure 6 is thought to be due to localization of move 

ment during deformation along a bentonitic tuff, which 

may have acted as a lubricant. 

AREA BETWEEN WESTERN SAN PEDRO AND PALOS 

VERDES DRIVE EAST 

In the area between western San Pedro and Palos 

Verdes Drive East the. northwestward-trending folds 

appear to bend southward and converge. Where they 

appear to converge, especially along San Pedro Canyon 

and its tributaries, the structure is very complex and 

irregular. The Altamira shale is strongly folded and the 

strata are- crushed and broken. In Averill Canyon 

they are locally overturned westward. Two faults in


this area shown on the geologic map of the preliminary 

paper 6 are omitted on the geologic map of the present 

report (pi. 1), as they are considered too uncertain. 

During construction of the Whites Point tunnel, 

squeezing ground,.manifested by buckling of the tunnel 

floor and movement of the walls and roof, was encoun 

tered in the area under discussion. The movement was 

evidently not due to weight of the overburden, for 

squeezing ground was not encountered farther north, 

where the overburden is as great or greater and the rock 

formations are essentially similar. It was due probably 

to release of elastically stored energy resulting from 

unexplained localization of strong deformation. Minor 

movement detected during construction of the tunnel at 

localities other than the Gaffey anticline and the area 

just mentioned appears to have been related to local 

zones of brecciated rock and fracture planes. 

WHITES POINT AREA 

In the Whites Point area the structure is complex. 

The fan-shaped anticline shown in figure 14 and in part 

SW. 

' /A/ /// / '/ ' /.'''u- x v 

y//j#±£iUll±^ 

The main schist area is in the northern part of a 

broad anticline, on which minor folds are superimposed. 

The crest of the hills in the San Pedro Hill area is 

marked by a shallow syncline. A general synclinal 

area, including the basin-shaped syncline at the head 

of Altamira Canyon, extends farther west along the 

crest of the hills. Toward the coast the synclinal area 

bends westward and merges into the extension of the 

synclinal area east of Bluff Cove. 

The southeastward-plunging Miraleste anticline is a 

well-defined fold in the Miraleste district. Its exten 

sion as one fold as far west as shown on plate 1 may 

not be justified. The southeastward-plunging Point 

Fermin anticline is not well-defined in the area of 

apparently irregular structure west of Fort McArthur 

Upper Reservation. 

The Cabrillo fault is the only fault of considerable 

extent shown on plate 1. At Cabrillo Beach, where 

the fault emerges on the coast, it dips 50° northeast 

ward at the base of the sea cliff and more steeply 

toward the top (pi. 6, D). At that locality cherty and 

mmwwm 

FIGURE .14. Fan-shaped anticline at Whites Point, a, Pleistocene terrace deposits; b, sandstone, conglomerate, and silty shale (middle (?) part of Altamira shale member 

Monterey shale, middle (?) Miocene); c, silty shale, silty sandstone, porcelaneous shale, and limestone (middle (?) and upper parts of Altamira shalo member of 

Monterey shale, middle (?) and upper Miocene). 

on plate 24, B, is exposed along the road on the east 

side of the point. A syncline 0.3 mile farther west is 

overturned southward. Its relations to the southward- 

overturned syncline south of the anticline shown in 

figure 14 are uncertain. The warm sulfur water at 

Whites Point Hot Springs rises presumably along a 

fracture in this area of complex structure. Sharp folds 

were observed in the WTiites Point tunnel between the 

south portal and a locality about 1,600 feet inland from 

the coast (pi. 1, sec. E E'}. These sharp folds stop 

abruptly at a series of shear zones that may mark a re 

verse fault, but that interpretation is uncertain. 

REMAINDER OF HILLS 

In the remaining parts of the Palos Verdes Hills the 

structure is relatively simple, the main folds being 

broad and gentle. Their prevailing trend is north 

west, but in the western part this trend is more west 

ward and the folds merge into the southwestward- 

trending folds of the Bluff Cove and adjoining areas. 

At many places there are sharp minor folds of local 

extent, and locally, as at Bluff Cove (fig. 5), sharp 

minor folds are overturned. An example of local dif 

ferential deformation is shown on plate 7, A. In the 

area shown diatomite and diatomaceous shale are more 

strongly deformed than underlying cherty shale and 

limestone. 

» Woodrlng, W. P., Bramlette, M. N., and Kleinpell, R. M., op. cit. (Am. Assoc. 

Petroleum Geologists Bull., vol. 20), fig. l (pp. 128-129). 

phosphatic shale in the upper part of the Altamira 

member of the Monterey is exposed on the hanging 

wall and buff siltstone in the middle part of the Alta 

mira on the footwall. The displacement at Cabrillo 

Beach is estimated to be between 100 and 200 feet. 

The entire blue-schist detrital facies of the upper part 

of the Altamira, about 300 feet thick at Point Fermin 

but thinning rapidly northward, and an undetermined 

thickness of the middle part of the Altamira are cut 

out. The abrupt termination of the thick basalt sill 

on the north limb of the Miraleste anticline in the 

Miraleste district is interpreted as evidence of a fault 

of similar displacement. No stratigraphic data were 

observed to substantiate the presence of a fault in the 

area between Cabrillo Beach and Miraleste, though at 

least a sharp flexure is evident. A fault of the extent 

shown on plate 1 is therefore hypothetical. A fault 

recognized in the Whites Point tunnel is correlated 

with the Cabrillo fault, as shoAvn in structure section 

E Er of plate 1. The fault so correlated is thought 

to cut off the 195-foot basalt sill penetrated in core 

hole 4.. Other nearby faults recognized in the tunnel 

might, however, with equal plausibility be correlated 

with the inferred surface fault. In a considerable part 

of _the area between Cabrillo Beach and Miraleste the 

inferred fault is drawn near the foot of a prominent 

scarp corresponding roughly to the boundary between 

soft rocks to the north and hard rocks to the south. 

The scarp is thought to mark hard-rock cliffs formed

during cutting of the Pleistocene marine terraces; that 

is, it is thought to be a structural inheritance, not a 

modern fault scarp. Near the coast the scarp is at the 

boundary of the. lowest terrace. It is improbable that 

the scarp in that area is the result of recent displace 

ment of the lowest terrace, for, other considerations 

aside, at Cabrillo Beach the fault is not at the foot of 

the scarp. The minor faults along Agua Negra Canyon 

arc based on mapping of the Miraleste tuff bed. In 

many 'other areas faults or brecciated zones were 

observed, but stratigraphic data are lacking at those 

localities. 

PHYSIO GRAPHY 

Marine terraces are the most striking physiographic 

feature in the Palos Verdes Hills. An old surface of 

considerable relief preserved as a rolling upland along 

the crest and upper slopes of the hills is thought to have 

been formed before the submergence and emergence 

that produced the terraces. 

MARINE TERRACES 

The marine terraces of the Palos Verdes Hills were 

described more than 50 years ago by Lawson, 7 who on 

the basis of the inadequate map then available recog 

nized 11 terraces. Thirteen main terraces are recognized 

in this report. Their designation is slightly different 

from that set forth in a preliminary paper, 8 owing to 

differentiation of the lowest terrace on the windward 

(west and southwest) and leeward (east and northeast) 

slopes and to consolidation of the terraces designated 

fourth and fifth in the preliminary paper. At least two 

other terraces are represented locally, but the total 

number is uncertain, owing to uncertainty in correla 

tions. 

The distribution, designation, and correlation of the 

terraces and profiles are shown on plate 22. It is not 

certain that all the benches so designated on that map 

represent marine terraces. Fossiliferous marine depos 

its, however, have been found on the bench platforms 

at so many localities shown on plates 1 and 22 that the 

benches are with considerable confidence considered 

marine terraces or remnants. Ill-defined benches not 

represented as terraces on plate 22 are doubtless terrace 

remnants, and at other localities terraces are unrecog 

nizable, owing to masking of any topographic expres 

sion. Fossil localities 84, 88, 91, and 92 are known, for 

example, to represent terraces without definite topo 

graphic expression. 

The terraces arc designated by number in ascending 

altitudinal order. This is not a logical arrangement, for 

the first terrace was the last to be formed. Nevertheless 

it is a convenient arrangement, as the lower terraces 

are better preserved and are correlated with greater 

confidence than the upper terraces. Furthermore, the 

thirteenth or highest terrace recognized may not be 

the oldest. The gentle slopes on San Pedro Hill above 

an altitude of 1,425 feet may represent an eroded higher 

terrace formed during complete submergence of the 

hills, as suggested by Lawson. 9 The 13 main terraces 

range in altitude from approximately 100 to 1,300 feet. 

The average interval between them is, therefore, about 

100 feet. The apparent intervals, as determined by the 

surface altitude at the rear of successive terraces, range 

' Lawson, A. C., The post-Pliocene dinstrophism of the coast of southern California: 

California Univ. Dcpt. Gcol. Bull., vol. 1, pp. 122-128, 1893. 

8 Woodrlng, W. P., Fossils from the marine Pleistocene terraces of the San Pedro 

Hills, Calif.: Am. Jour. Sci., 5th ser., vol. 29, p. 295,1935. 

' Lawson, A. C., op. cit., p. 127. 

PHYSIOGRAPHY 113 

from 75 to 200 feet. The actual intervals, as determined 

by the altitudes of the platforms at the rear of successive 

terraces, are for the most part indeterminable. A ter 

race intermediate between the seventh and eighth, 

designated 7a, is recognized inland from Point Vicente 

(pi. 22, profile E E'~), and another intermediate 

between the fifth and sixth, designated 5a, is recognized 

inland from Flatrock Point. 

The terraces are most clearly visible on the windward 

west coast (pis. 8, 22, profiles A-A' to E-E'', 24tf, 25, 26) 

and on the windward southwest coast from the south 

slope of San Pedro Hill to Point Fermin (pi. 22, profile 

G-G'). In both areas the prevailing platform rock is 

hard Miocene cherty shale. The continuity of the 

terraces in the intervening area is broken by the steep 

greatly eroded slope and by landslides. On the leeward 

east and northeast slopes the first terrace truncates 

unconsolidated lower Pleistocene sediments and soft 

Miocene mudstone and diatomaceous shale and is, there 

fore, exceptionally wide. On the leeward east slope in 

San Pedro the fourth and fifth terraces are also wide, as 

the platforms truncate relatively soft Miocene shale, 

the scarp from Miraleste to Cabrillo Beach marking 

in general the boundary between soft rocks and.hard 

rocks. Elsewhere on the leeward slopes, where the 

prevailing platform rock is hard cherty shale, as it is on 

the windward slopes, the terraces, with a few notable 

exceptions, are less well-defined than on the windward 

slopes. 

The apparent merging of terraces, as shown on plate 

22 on both map and profiles, is due to the cover of 

nonmarine debris, designated the nonmarine terrace 

cover, that accumulated on the platform and its marine 

deposits following emergence. This phase of marine 

terrace development along the mountainous California 

coast was first clearly described and analyzed by 

Davis 10 in his description of the terraces along the 

coast of the western Santa Monica Mountains. Non- 

marine deposits on marine terraces had been described 

previously, of course, as by Trask n in his description 

of the terraces along the coast of the Santa Lucia 

Mountains and by Hoots 12 in his description of the 

Santa Monica Plain. The nonmarine cover, described 

under the heading "Nonmarine terrace cover," page 106, 

ranges in thickness from a thin veneer near the sea 

ward edge of a terrace that has not been eroded far 

back to an observed maximum of about 100 feet near 

the rear of a terrace. As shown in figure 15, a thick 

nonmarine cover may extend seaward over the next 

lower terrace, or still lower terraces, forming a multiple 

cover and concealing the sea cliff between successive 

terraces, as was observed by Trask 13 and inferred by 

Davis. 14 An illustration of a multiple cover that con 

ceals the sea cliff between the fourth and third terraces 

may be seen in a highway cut near Point Vicente (plate 

23). Depending on the thickness of the nonmarine 

cover, the surface altitude at the rear of a terrace may 

be close to the platform or may be 100 feet or more 

above it. With few exceptions the nonmarine cover on 

terraces older than the fifth is not shown on the geo 

logic map (pi. 1). On the upper terraces the coyer is 

so thin owing to erosion that it was not differentiated 

from ordinary surficial debris; in fact, at and near the 

10 Davis, W. M., Glacial epochs of the Santa Monica Mountains, Calif.: Qeol. 

Soc. America Bull., vol. 44, pp. 1055-1056, 1058-1061, figs. 5, 6, 1933. 

11 Trask, P. D., Geology of the Point Sur quadrangle, Calif.: California Univ., 

Dept. Geol. Sci., Bull., vol. 16, pp. 158-159,1926. 

12 Hoots, H. W., Geology of the eastern part of the Santa Monica Mountains, Los 

Angeles County, Calif.: U. S. Geol. Survey Prof. Paper 165, pp. 122-123, 1931. 

13 Trask, P. D..op. cit. 

» Davis, W. M., op. cit., pp. 1,086-1,087, figs. 19, 20.


rear of a terrace the uppermost part of the cover is 

ordinary surficial debris. 

Correlations of terrace remnants are doubtful, owing 

to discontinuity on the windward slopes, to poor de 

velopment on much of the leeward slopes, and above 

all to the varying thickness of the nonmarine cover and 

to the masking effect of multiple covers. Terrace 

platforms are well exposed along the present sea cliff 

and in canyons as much as a few hundred feet inland. 

The platform of the first terrace, which covers an ex- 

tensive area, is visible in many natural exposures. 

With few exceptions, natural exposures of platforms 

older than the first were not seen any distance inland 

from the present sea cliff, even in areas where the ter 

races were well-defined. All the fossil localities shown 

on plate 22 more than a few hundred feet inland from 

the present sea cliff represent highway cuts or other 

artificial excavations. In the absence of information 

on numerous platform altitudes at the foot of the sea 

cliff at the rear of terrace correlations are dubious.


Platform of fourth terrace' 

HiP , 

Marine deposits 

\ 

V. 

Fossil locality 84 

' "vesto 

I). 

Platform of third terrace 

CUT ON PALOS VERDES DRIVE SOUTH, NEAR POINT VICENTE, SHOWING PLATFORMS OF FOURTH AND THIRD TERRACES AND INTERVENING 

SEA CLIFF. 

Owing to foreshortening, platform of fourth terrace appears to slope to left.

GEOLOGICAL SUEVEY PROFESSIONAL PAPER 20?" PLATE 24 

A. PALOS VEKDES (?) SAND (b) AND OVERLYING NONMARINE TERRACE COVER (a) 

RESTING UNCONFORMABLY ON MIOCENE SHALE (c) IN CUT ON PALOS VERDES 

DRIVE EAST, NEAR GEORGE F CANYON. 

C. NORTHWARD VIEW ON WEST COAST SHOWING MARINE TERRACES. FOURTH 

TERRACE IN FOREGROUND, FIFTH AND SEVENTH ON SKYLINE. 

B. SOUTH LIMB OF F\N-.-M \I'KD ANTICLINE AT WHITES POINT. 

D. HANGING VALLEY AT HEAD OF VALMONTE CANYON. 

TERRACE DEPOSITS AND STRUCTURAL AND PHYSIOGRAPHIC FEATURES OF THE PALOS VERDES HILLS.


AIIil'LANE VIEW ON WEST COAST OF PALOS VERDES HILLS LOOKING FROM BLUFF COVE SOUTHWESTWARD TOWARD LUNAUA BAY. 

Numbers represent marine terrace designations. (See pi. 22.) Photograph by Fairchild Aerial Surveys. 

PROFESSIONAL PAPER 207 PLATE 25


VIEW ON WEST COAST OF PALOS VERDES HILLS LOOKING SOLTHWESTWARD FROM MALAGA COVE. 

Terrace at top of cliff at the left, the lowest terrace in the Palos Verdes Hills, is deformed; it slopes toward the hills, not away from them. In middle of view and toward right 

it has normal seaward slope. Lowest building on skyline is on fifth terrace, building with tower is on sixth. Photograph by Palos Verdes Estates.


A. UNDRAINED DEPRESSION ALONG CREST OF WESTERN PART OF HILLS. 

B. HANGING VALLEY AT HEAD OF ALTAMIRA CANYON. 

Lip of valley is in right middle foreground. Contrary to appearance it drains to right. 

C. HEAD OF ALTAMIRA CANYON TAPPING HANGING VALLEY SHOWN IN B. 

ROLLING UPLAND ALONG CREST OF PALOS VERDES HILLS.

Those shown on plate 22 are based on relative width of 

terrace treads and on the assumption that the terraces 

are not deformed to any notable extent except along 

and near the north border of the hills, an assumption 

that appears to be justified by benches identified as 

remnants of the seventh terrace. The correlations are, 

however, far from satisfactory, others may be equally 

plausible or more plausible. Recognition of specific 

terraces and their correlation in the Ventura district 

also were found by Putnam 15 to be difficult. 

The thirteenth, twelfth, and eleventh terraces are 

identified with reasonable certainty only on the slopes 

of San Pedro Hill, where they form narrow spur 

benches. The platform of the twelfth terrace is ex 

posed at locality 75 in a cut on Crest Road. The 

marine and nonmarine terrace 'deposits described on 

page 54 are visible at that locality, and the marine 

fossils listed on page 94 were collected there. The 

crest and upper slopes of the hills northwest of San 

Podro Hill include presumably eroded remnants of 

these uppermost terraces. 

The tenth', ninth, and Seventh terraces are well- 

defined on the west slope of the hills, and the tenth, 

ninth, eighth, and seventh are well-represented on the 

slopes of San Pedro Hill. The tenth and ninth are 

ident fied locally on the northeast slope, and the 

eighth and seventh in the greater part of that area. 

The seventh is the widest terrace on the west slope, dis 

regarding apparent merging of the second and third, 

and is the highest terrace identified around the north 

west end of the hills. At most places on the west 

slope the eighth evidently was removed during cutting 

of the wide seventh. On the east and northeast 

slopes the eighth as identified is wider than the seventh, 

for example, in the Miraleste district and along Agua 

Negra Canyon, which cleanly cuts a wide bench cor 

related with the eighth. Perhaps the eighth terrace 

of the east and northeast slopes corresponds to the 

seventh of the west slope, but the correlations adopted 

appear to agree better with identifications of the seventh 

around the northwest end of the hills. Another pos 

sibility is that the eighth and seventh terraces shown 

on plate 22 represent more than two terraces. An 

.intermediate terrace (7a) is recognized inland .from 

Point V:icento. If it is represented on the east and 

northeast slopes, it has not been differentiated. Ac 

cording to surface altitudes at the rear of the seventh 

terrace, it slopes gently southward on the west coast. 

As the relation is uniform and is shown, though to less 

marked degree, by the ninth and tenth, it indicates 

slight tilting. 

The sixth terrace is well-defined at the northwest end 

of the hills (pi. 22, profile A A), is represented by a few 

remnants on the west slope, and is identified on the 

ridge extending southeastward from San Pedro Hill and 

at localities farther west and north,, but is not recog 

nized on the northeast slope. 

The fifth and fourth terraces are well-developed at 

the northwest end and on the west slope of the hills. 

There these terraces form treads of moderate width 

that appear to be tilted slightly southward like the 

higher terraces in that area. A terrace intermediate 

between the fifth and sixth (5a) is recognized at the 

northwest end. On the northeast slope the fourth and 

fifth as identified rise southeastward until in the central 

part of that area they reach altitudes 225 and 250 feet 

higher than at the northwest end. Southeastward and 

i» Putnam, W. C., Ooomorphology of the Ventura region, Calif.: Qeol. Soc. Am' 

Bull., vol. 53, p. 730, 1942. 

115 

southward on the northeast and east slopes the altitude 

drops, and on the southwest coast inland from Whites 

Point it is the same as at the south end of the west slope. 

As the altitudes are not based on platform altitudes, 

misidentifications of terraces and failure to differentiate 

terrace 5a may be involved. Nevertheless the apparent 

arching appears to be uniform. Inasmuch as the upper 

terraces do not show the same relation, the arching is 

to be correlated presumably with proximity to the 

mobile north border of the hills, where the first terrace 

is interpreted as showing similar arching to a more 

marked extent. 

The third is a narrow terrace. It would be grouped 

probably with the minor terraces 7a and 5a were it not 

for its younger age and consequently more perfect 

preservation at more numerous localities on both the 

west and east slopes of the hills. Along most of the 

south coast the fourth merges apparently into the 

second. That this relation is due to a multiple non- 

marine cover is shown by the exposure at fossil locality 

84 near Point Vicente already mentioned (pi. 23). At 

fossil locality 99, on Portuguese Bend, the nonmarine 

cover at a location corresponding approximately to 

the rear of the second terrace is about 100 feet thick, 

the greatest observed thickness. On the east slope 

inland from Fort McArthur Lower Reservation in 

southern San Pedro the third terrace forms a narrow 

steeply sloping bench northward from fossil locality 90 

but no perceptible bench at localities 91 and 92, where 

the platform and the marine deposits resting on it are 

exposed in street cuts. 

The second terrace js the lowest terrace along the 

windward coasts except at Long Point, where a land 

ward remnant of the first terrace represented princi 

pally by»a bare rock platform is identified, and at 

Malaga Cove, where the first terrace is well-preserved. 

In San Pedro the second is differentiated locally from 

the first, but it generally merges apparently into the 

first. It is improbable that the second terrace at Point 

Fermin is the first terrace at Cabrillo Beach uplifted 

along the Cabrillo fault, for at the coast the fault 

emerges on the rise between these two terraces. 

The first terrace is extensive in San Pedro and on the 

northeast border of the hills. In areas where mapped 

marine and nonmarine deposits lie on the platform, 

the terrace map (pi. 22) agrees with the geologic map 

(pi. 1). The platform and the deposits lying on it are 

undeformed in San Pedro. Along the northeast border 

they are gently folded along the Gaffey anticline and 

Gaffey syncline. Farther west they are abruptly bent 

upward at the border of the hills and are at places 

faulted. In both areas of deformation the platform 

and the surface have no longer the usual physiographic 

features of a terrace tread. In fact, the abrupt bending 

at the border of the hills produces the physiographic 

effect of a terrace rise. South of the areas where the 

terrace is deformed the first terrace as identified rises 

northwestward from San Pedro and southeastward 

from Malaga Cove, until it reaches altitudes 275 or 300 

feet greater than in San Pedro and at Malaga Cove. 

Perhaps apparently merging terraces representing the 

second and third as well as the first are confused in 

this apparent arching. The exceptionally great thick 

ness of marine sand and gravel along the north border 

near Hawthorne Avenue (p. 59) may include deposits 

laid down during cutting of the first and one or more 

older terraces. At several localities, however, as along 

Palos Verdes Drive North, only one terrace platform


and only one set of terrace deposits appear to be 

involved. The second and third terraces are, therefore, 

inferred to have been removed along most of the north 

east slope during cutting of the first. The absence of 

an exceptionally high cliff at the rear of the first may 

be due to masking by the nonmarine cover. Unfor 

tunately, in the area between Malaga Cove and 

Valmonte, where the first terrace is thought to rise east 

ward about' 300 feet in a distance of IK miles, the 

terraces are concealed by dune sand. At Malaga Cove 

the first terrace is plainly arched over the strongly 

deformed Miocene and Pliocene formations (pi. 26; 

fig. 7). The platform is, however, not abruptly bent 

downward at the border of the hills, as it. is east of the 

dune sand area. 

ROLLING UPLAND 

The crest and upper slopes of the hills are character 

ized by wide swalelike valleys of gentle gradient that 

stand in marked contrast to the narrow steep-gradient 

canyons at lower levels. The wide valleys and inter 

vening low smoothly rounded divides form a rolling 

upland. Plate 4 shows the upland skyline and the deep 

canyons trenching the upland surface in the area inland 

fro'm Inspiration Point. Other views of the upland are 

-SW. 

Furthermore, it is unlikely that terrace platforms and 

the thin veneer of unconsolidated marine sediments, 

such as those on the platform of the twelfth ten-ace 

at locality 75, would escape destruction during develop 

ment of the surface. The erosion surface was formed 

presumably during the period between the early Plio 

cene submergence and the late Pleistocene submer 

gence. That it was probably the result of erosion of 

an area larger than the present Palos Verdes Hills is 

indicated by the stream profiles of figure 16. If the 

hanging valleys along the upper course of Altamira 

Canyon and Valmonte Canyon were graded to the 

same base level, the hanging valley of Altamira Can 

yon is to be projected a considerable distance to repre 

sent that base level. The high-level terraces may be 

the result of relatively brief periods during which the 

old erosion surface was modified by terracing of exposed 

headlands. Under that hypothesis the ninth and 

tenth terraces are exceptionally well developed on the 

west slope of the hills. That coast of the emerging 

island was, however, evidently most exposed to marine 

erosion, as lower terraces are more uniformly well- 

developed there than in any other part of the hills. 

The rolling upland contains several undrained 

depressions, which are most numerous at the northwest 

FIGUEE 16. Stream profiles showing hanging valleys. A, Valmonte Canyon, north slope of hills. B, Altamira Canyon, south slope of hills. 

shown on plate 27. The swalelike valleys are left hang 

ing where the deep canyons advancing inland tap them. 

Examples of such hanging valleys are shown on plates 

24, D and 27, 5, C. Profiles of Valmonte Canyon and 

Altamira Canyon, shown in those views, are reproduced 

in figure 16. In the eastern part of the hills terrace 

remnants are found at altitudes as great as 1,300 feet 

above sea level. On the west slope the rolling upland 

is limited by the tenth terrace, which is at an altitude 

of 1,050 feet above sea level. On parts of the north 

slope the upland surface is identified at altitudes corre 

sponding to the eighth and seventh terraces. 

As has already been pointed out, 16 the rolling upland 

has the features of an old erosion surface. It is im 

probable that this erosion surface, which has a relief of 

about 700 feet, was developed on a small island emerg 

ing after the almost complete, or complete, submergence 

during which the high-level terraces were formed. An 

erosion surface of this character is not expectable on a 

small island emerging at a relatively rapid rate. 

"> Kew, W. S. W., Geologic and physiographic features in the San Pedro Hills, 

Los Angeles County, Calif.: Oil Bull., vol. 12, No. 5, pp. 517-518, 1926. 

Mile 

end of the hills. Plate 27, A, is a view of the largest 

depression in that area, filled with water after winter 

rains. 'The hanging valley in plate 27, B, also has a 

slight closure, evidently less than 5 feet, for after rains 

water stands in its lower part. One of the depressions 

is on the tread of the tenth terrace on the west slope, 

another, \% miles northeast of Long Point, is on a flat 

surface representing probably an eroded remnant of the 

twelfth terrace. It has been suggested 17 that these 

depressions are the result of drainage changes caused 

by downward tilting toward the east. Some of the 

depressions support that interpretation, but others, 

such as that 0.2 mile northeast of the 1,216-foot hill 

near the northwest end of the upland, appear to indicate 

tilting in the opposite direction. It is more probable 

that the depressions are the result of underground 

solution of thin beds of limestone and settling along the 

gentle-gradient valleys of the rolling upland. Decrease 

of the drainage areas and consequently the run-off which 

resulted from the tapping of the drainage basins of the 

upland by steep-gradient canyons may have played a 

" Kew, W. S. W., op. cit., p. 518.

part in the development of some of the depressions. It 

is unlikely, however, that drainage modifications had 

anything to do with the depression on the tenth terrace. 

The peculiar cirquelikc valley head just north of the 

crest of the hills, opposite the head of Agua Amarga 

Canyon, may represent a stage in the development of 

a depression. 

MINOR PHYSIOGRAPHIC FEATURES 

Landslides. An extensive landslide area forms the 

hummocky topography inland from Portuguese Point 

and Inspiration Point (pi. 5). , As explained on page 18, 

the landslide is attributed to movement into a structural 

basin, along a gliding plane formed by water-soaked 

be.nton.itic tuff. Smaller landslides found elsewhere on 

steep slopes are not known to be related to particular 

rock types. 

Landsliding or slumping of a different type took place 

a«quarter of a mile east of Point Fermin in 1929. A 

semiclliptical area extending 1,000 [feet along the 100- 

foot sea cliff and 400 feet inland moved seaward as 

a body, leaving a main fissure 5 to 10 feet wide and an 

irregularly fissured zone as much as 50 to 100 feet wide. 

The sliding was attributed by Miller 1S to seaward down- 

dip movement on slippery shale on the south limb of the 

Point Fermin anticline. Soon after it was formed, the 

fissure was filled with fossiliferous San Pedro sand from 

Second and Beacon Streets. Movement that took 

place again in 1940 suggests that the slumped mass 

rotated upward as it moved toward the ocean and that 

stability has not yet been reached. As a result of 

exceptionally heavy rains the Point Fermin slide was 

active again in March 1941. 

Dune sand. The extreme northwestern part of the 

h ills is covered with dune sand and forms the south 'end 

of a dune-sand strip extending northward along the 

coast about 10 miles to Playa Del Ray. 

EVENTS SINCE EMERGENCE OF LOWEST TERRACE 

the north border of the hills the lowest terrace 

was deformed following emergence and deposition of 

the nomnarine cover. On most of the west coast and 

along virtually the entire south coast the lowest terrace 

has been destroyed by cutting of the present off-shore 

platform. The valley followed by Gaffey Street was 

cut across the warped lowest terrace by an antecedent 

stream or by a stream that breached the Gaffey anti A 

cli.no by headword erosion and captured a stream for 

merly draining southeastward north of the anticline. 

The natural features of the floor of this valley have 

been altered by construction of a sump. It appears 

probable, however, that slight recent growth of the 

Gaffey anticline has resulted in the impounding of 

water in Bixby Slough north of the anticline. The 

stream formerly had a greater flow to keep pace with 

the rising anticline, or recent upwarp was more rapid 

than formerly. 

RELATIONS TO NEARBY AREAS 

At the north border of the hills the marine and 

overlying nonmarine deposits of the lowest terrace dip 

down to the level of the Los Angeles Plain. The non- 

marine deposits merge into the older alluvium of the 

Los Angeles Plain and other parts of the Los Angeles 

Basin. Lithologically and physiographically the non- 

i» Miller. W. J., The landslide at Point Fermin, Calif.: Sci. Monthly, vol. 32, pp. 

464-469, 5 flgs., 1031. 

PHYSIOGRAPHY 117 

marine cover is indistinguishable from the older allu 

vium of the basin. They are essentially equivalent, 

though the older alluvium may represent a time interval 

corresponding to several of the lowest terraces in the 

Palos Verdes Hills. Eight miles northeast of the 

Palos Verdes Hills the older alluvium is arched over 

the Dominguez anticline forming Vickery's Dominguez 

surface. 19 The famous Rancho La Brea asphalt de 

posits, on Wilshire Boulevard in western Los Angeles 

20 miles north of the Palos Verdes Hills, are in alluvium 

that is probably of essentially the same age as the older 

alluvium arched over Dominguez Hill but was de 

posited north of a valley along a former course of the 

Los Angeles River. The Rancho La Brea mammals 

are now generally considered late Pleistocene. The 

fragmentary mammalian remains from the marine de 

posits on the lowest terrace in San Pedro are not 

inconsistent with the view that they are of essentially 

the same age as the Rancho La Brea mammals. 20 

Grant and Sheppard 21 presented arguments indicating 

that on physiographic grounds the alluvium at Rancho 

La Brea is of late Palos Verdes or possibly post-Palos 

Verdes age. 

Two marine terraces along the coast of the western 

Santa Monica Mountains, 20 to 45 miles northwest of 

the Palos Verdes Hills, were attributed by Davis 22 to 

the effects of rising sea level during two periods of 

Pleistocene deglaciation with uplift between the two 

periods and after the later period. Owing to the great 

thickness of the nonmarine cover on the lower terrace 

and to the extensive erosion represented by the present 

offshore platform, the present platform was attributed 

to the effects of the last two nonglacial periods (the last 

being the present period), between which no uplift took 

place. Davis 23 pointed out that the terraces may be 

attributed to land movements and that assignment of 

the present offshore platform to two instead of one 

period of deglaciation is doubtful. Tilting of the lower 

terrace downward to the west 200 or 300 feet within a 

distance of 30 miles shows that uplift took place after 

the platform was formed. The terraces were attributed 

by Davis to the effects of delgaciation, because' they 

are Pleistocene and because, if they were explained by 

land movement only, no account would be taken of the 

effects of rising and lowering sea level resulting from 

Pleistocene^ deglaciation and glaciation. 

That the marine terraces of the Palos Verdes Hills 

are due principally to uplift is suggested not only by 

their number and great altitude but also by deforma 

tion of the lower terraces along the north border of the 

hills. The effects of Pleistocene glaciation and degla 

ciation are unrecognizable, or at least unrecognized," in 

this actively emerging area. As pointed out by 

Davis, 24 uplift may increase, decrease, or neutralize 

effects of changes of sea level produced by glaciation 

and deglaciation. He 25 suggested that if a sufficient 

number of examples of Pleistocene terraces are studied 

at altitudes of as much as 1,000 feet or more along the 

California coast a correlation between terraces and 

periods of glaciation and deglaciation may be evident 

" Vickery, F. P., The interpretation of the physiography of the Los Angeles coastal 

belt: Am. Assoc. Petroluem Geologists Bull., vol. 11, pp. 417-419, flg. 1, 1927. . 

>° Stock, Chester, Cenozoic gravigrade edentates of western North America, with 

special reference to the Pleistocene Megalonychinae and Mylodontidae of Rancho La 

Brea: Carnegie Inst. Washington Pub. 331, p. 119,1925. 

« Grant, U. S., IV, and Sheppard, W. E., Some recent changes of elevation in the 

Los Angeles Basin: Seismological Soc. Am. Bull., vol. 29, p. 308, 1939. 

33 Davis, W. M., Glacial epochs of the Santa Monica Mountains, Calif.: Geol. Soc. 

America Bull., vol. 44, pp. 1,044-1,048, 1933. 

23 Idem, pp. 1,044-1,045, 1052, 1060, 1,067, 1,075. 

s« Idem, p. 1045. 

«Idem, pp. 1107-1108.


on the grounds that terraces formed during rising sea 

level would be wide, whereas those formed during 

lowering sea level would be narrow. The seventh 

terrace in the Palos Verdes Hills, which is exceptionally 

wide on the.west slope and is identified around the 

northwest end of the hills, may .represent a period of 

rising sea level. On the contrary, it may represent a 

relatively long period of crustal stability. Even if a 

sufficient number of examples were found to justify 

D avis' suggested analysis, effects of varying deforma- 

tional history in different areas may have obliterated 

or obscured effects of rising and lowering of sea level. 

MINERAL RESOURCES 

OIL POSSIBILITIES 

Asphalt is abundant locally in the Altamira member 

of the Monterey shale and occurs at places in the Val- 

mohte diatomite and Malaga mudstone members. 

Bedding and joint planes in blue-schist sandstone in 

the upper part of the Altamira on the east side of 

Point Fermin contain much asphalt and some layers 

of sandstone are impregnated with it. Fractures and 

joints in sandy limestone at the junction of the main 

branches of Agua Amarga Canyon contain asphalt. 

Beds of vitric volcanic ash exposed in Peck Park in 

strata assigned to the Altamira and similar material in 

the Valmonte along the coast between Cabrillo Beach 

No. on 

plate 1 

1 

2 

3 

4 

5 

6 

7 

8 

e 

10 

11 

12 

13 

Name 

Traders Oil Co., Weston 

No. 1. 

Petroleum Securities Co., 

Weston No. 1- 

Harbor Crude Oil Co., 

Wheat No. 1. 

Rolling Hills Petroleum 

Co., Weston No. 1. 

A. T. Jergins Trust, Palos 

Verdes No. 1. 


Narbonne No. 1. 


Palos Verdes. 

E. O. Lewis, Palos Verdes 

No. 1. 

Palos Verdes No. 1. 

Keck Syndicate, Burkhard 

No. 6-2. 

Southern California Drill 

ing Co., Burkhard No. 1. 

Hogan Petroleum Co., 

Burkhard No. 1. 

Burkhard No. 2. 

and Fort McArthur Lower Reservation are stained 

black with asphalt. During construction of the 

Whites Point tunnel asphalt was observed at numerous 

localities -in the Altamira shale and at a few localities 

in the Malaga mudstone member. The most con 

spicuous deposits in the tunnel are in fractured dia- 

tomaceous shale of the Altamira immediately below 

the unconformity with the Pleistocene Lomita marl on 

the south limb of the Gaffey syncline. Elsewhere in 

the tunnel asphalt was observed in sandstone, along 

bedding planes in shale, and in fractures in limestone. 

A thin layer of asphalt was found at the contact 

between mudstone and schist conglomerate on the 

north limb of the anticline, along the crest of which 

schist was penetrated, but no asphalt was observed in 

the conglomerate. The fractured basaltic rock en 

countered farther south is impregnated with asphalt. 

The indications of oil in the Palos Verdes Hills and 

the widespread occurence of oil in upper Miocene ajid 

Pliocene formations in Los Angeles Basin fields nearby 

have encouraged prospecting in the hills. Data on 

wells that have been drilled in the hills and near the 

north border are summarized in the following table. 

The table does not include several shallow wells in or 

near San Pedro nor two wells reported to have been 

drilled during 1910 and 1911 near Malaga Cove to 

depths of 1,100 and 1,285 feet. 26 

26 Prutzman, P. W., Petroleum in California: California Mining Bur. Bull. 63, 

p. 328, 1913. The location of the wells is shown on a small-scale map of southern 

California in the pocket. 

Wells drilled for oil in Palos Verdes Hills and near north border of hills 

General location 

North of north border of 

hills along Redendo- 

Wilmington Blvd. 

North border of hills west 

of Sepulveda Canyon. 

.....do.. ................ 

....-do. ................. 

Near north border of hills 

between Agua Magna 

Canyon and Bent Spring 

Canyon. 


immediately west of 

Palos Verdes Drive East. 


west of Gaffey St. 


east of Gaffey St. 

..do.................... 


west of Gaffey St. 

Valley of lower George F 

Canyon. 

Northeastern part of hills 

near Harbor Blvd. 

. ....do.... ............. 

Approxi 

mate- 

altitude 

(feet) 

130 

175 

250 

) 

180 

410 

276 

261 

155 

40 

210 

112 

25 

65 

Depth 

(feet) 

3,392 

3, 256 

3,866 

6,580 

2,782 

4,554 

2,521 

4,498 

4,496 

3, 300 

1,440 

2,556 

3, 734 

Approxi 

mate 

altitude 

of schist 

basement 

(feet) 

-1,785 

-1.263 

Date 

drilled 

1919-22 

1927 

1925-26 

1925-26 

1926 

1922-23 

1923-25 

1937 

1938 

1938 

Remarks 

Penetrated base of Pleistocene strata at depth of 1,800 feet. 

Brown shale with shows of oil from that depth to bottom. 

Brown shale includes presumably Pliocene and upper 

Miocene formations. 

Penetrated calcareous sediments lithologically and faunally 

similar to Lomita marl at depth of 1,000 to 1,318 feet. Al 

most vertical upper Pliocene strata at depth of 1,500 to 

3,063 feet. Miocene strata, dipping 55° to 60°, from that 

depth to bottom. Pliocene and Miocene formations in 

fault contact. 

Penetrated mostly brown shale from depth of 800 feet to 

bottom. Some oil shows below 1,800 feet. 

Redrilled in 1937. Lower Pliocene-Miocene contact reported 

at estimated depth of 1,960 feet. 

feet, lower Pliocene dipping 30° to 35° at depth of 1,975 to 

2,650 feet, and reentered almost vertical upper Miocene at 

depth of about 3,000 to 4,000 feet. Miocene from depth of 

4,100 feet to bottom dipping 15° to 40°. Oil shows in 

nodular shale below 5,800 feet and in conglomerate below 

6,450 feet. 

Penetrated mostly brown shale, presumably Miocene, greatly 

sheared and dipping from 20° to almost vertical. Altered 

igneous rock at depth of 2,037 to 2,050 feet. Schist from 

depth of 2,195 feet to bottom. 

Penetrated Miocene strata at depth of about 350 to 2,600 feet, 

then lower Pliopene, and reentered upper Miocene at depth 

of about 3,100 feet. Miocene consists mostly of sheared and 

steeply dipping hard brown shale. 

Penetrated mostly Miocene brown shale, sheared and generally 

dipping 25° to 75°. 

Penetrated sand and gravel to a depth of 605 feet and mostly 

brown shale, presumably Pliocene and Miocene, below 

that depth. Oil shows below depth of 1,800 feet. 

of about 4,300 feet and upper Miocene brown shale below 

that depth. Average dip about 10°. 

Penetrated mostly brown shale, presumably Miocene. 

Penetrated Pleistocene-Miocene contact at depth of about 

500 feet. Miocene strata consist of diatomaceous shale, 

brown shale, cherty shale, and silty phosphatic shale, 

mostly sheared and dipping 20° to 90°. Decomposed schist 

or schist conglomerate at depth of 1,317 feet, schist at 1,375 

feet. 

Penetrated Pleistocene strata to depth of 1,039 to 1,092 feet 

and Miocene below 1,092 feet. Miocene strata fractured 

and sheared, average dip 60°. 

lower Pliocene at depth of 2,192 feet, and upper Miocene 

at depth of 3,159 to 3,301 fcot. Average dip of lower Plio 

cene 45°; average dip of Miocene 75°.

No. on 

pinto 1 

14 

16 

10 

17 

18 

Name 

J. K. Wolirman Oil Co...- 

Oil and Gas Co. 

Los Angeles Harbor Devel 

opment Co. 

voda No. 1. 

Palos Verdes No. 1. 

MINERAL RESOURCES 119 

Wells drilled for oil in Palos Verdes Hills and near north border of hills Continued 

General location 

West central San Pedro... 

Southwestern San Pcdro.. 

Approxi 

mate 

altitude 

(feet) 

270 

15 

225 

155 

70 

Depth 

(feet) 

Most of the wells located well within the hills pene 

trated the schist basement. Schist may be expected, 

except in the extreme northeastern part of the hills, at 

altitudes ranging from 1,000 feet above sea level to about 

5,000-feet below sea level, depending on location. In 

most of the area depth to the schist basement may be 

estimated with a reasonable degree of certainty. South 

of San Pedro Hill and farther west on the south slope 

estimates are uncertain, owing to the undetermined 

rate of southward thickening of Miocene strata indi 

cated by wells drilled near Point Fermin and Long 

Point. The Burkhard well of the Southern California 

Drilling Co.. near the trough of the Gaffey syncline, 

reached solid schist at a depth of 1,263 feet below sea 

level and decomposed schist or schist conglomerate 58 

feet higher. The altitude of the schist basement in this 

well agrees with the ccmbined surface and Whites 

Point tunnel structure section E E' of plate 1. 

Four wells were drilled along or close to the north 

border of the hills west of the eastward bend in the 

border in southern Harbor City. In each of the wells 

for which adequate records are available strongly 

deformed strata were penetrated. Two of the wells are 

reported to have passed from upper Miocene strata 

into lower Pliocene and then reentered upper Miocene. 

The abnormal stratigraphic relations show overturning 

or more probably penetration of a thrust fault. 

Six wells are located in the extreme northeastern part 

of the hills. The McAdams well penetrated a thick 

gently dipping lower Pliocene section. Drilled to a 

depth of 4,456 feet below sea level, only about the 

lowermost 196 feet is reported to represent Miocene. 

A mile west-southwest of the McAdams well Pleistocene 

strata rest directly on upper Miocene. The thick 

lower Pliocene section encountered in this well, there 

fore, thins rapidly westward, owing presumably to the 

unconformity at the base of the Pleistocene. It is not 

known whether, the Lewis well, which reached a depth 

of 4,343 foot below sea level, penetrated deposits of 

lower Pliocene age, but it presumably did. The Keck 

well readied a depth of 3,090 feet below sea level and 

the Petroleum Securities Palos Verdes well a depth of 

2,260 feet below sea level. The Keck well is located 

near the surface crest of the Gaffey anticline. Accord 

ing to structure section E E'', plate 1, and the record 

of the Burkhard well of the Southern California 

Drilling Co., schist might be expected on the crest of the 

Gaffey anticline along the line of structure section 

E E' at a depth of about 1,000'feet below sea level. 

The record of the Keck well shows, however, that the 

schist basement is at a greater depth. A subsurface 

fault of considerable displacement with downthrow to 

the north corresponding in position approximately to 

the axis of the Gaffey syncline is indicated by these 

1,054 

3,750 

2,044 

1,480 

4,500 

Approxi 

mate 

altitude 

of schist 

basement 

(feet) 

-893 

-3, 285 

-1,800 

-3, 830 

Date 

drilled 

1931-34 

1922-26 

1922 

1941-42 

1941 

Remarks 

Penetrated mostly brown shale, presumably Miocene. Enter 

ed schist conglomerate at depth of about 800 feet and schist 

at depth of 1,163 feet. 

Penetrated schist at depth of 3,300 feet. 



relations. The sheared and steeply dipping brown 

shale reported in the Petroleum Securities Palos Verdes 

well shows steep dips on the north limb of the anticline 

close to the crest. Similar features are apparent in the 

Malaga muds tone at the surface nearby and in the 

Whites Point tunnel. Steep dips and probable faults 

were encountered in the two wells drilled by the 

Hogan Petroleum Co. near Harbor Boulevard. Nich- 

olson 27 concluded that changes in level in the harbor 

district indicate a fault in the northern part of the 

district. 

The results of drilling are not encouraging. The 

possibility of finding oil within the hills in sandstone 

and conglomerate resting on schist at structurally 

favorable localities and at localities where overlap may' 

be effective has not, however, been tested thoroughly. 

Strongly deformed Miocene and Pliocene strata are to 

be expected along the north border of the hills at least 

as far east as the eastward bend in the border. If 

sandy beds are present in the Miocene or at the contact 

between Miocene sediments and schist, oil may have 

moved southward up dip from the syncline between the 

hills and the Torrance anticline and accumulated at 

the border of the hills, where the schist basement is 

abruptly upturned or faulted. Oil showings in the 

Rolling Hills well indicate that there is some oil in that 

area. Prospecting in the expectation of fin ding possible 

accumulation of this type is likely to be uncertain and 

expensive, at least until the subsurface structure is more 

definitely determined. The subsurface structure in the 

extreme northeastern part of the hills is evidently not 

simple. Sand is reported to be absent in the lower 

Pliocene Repetto formation of that area and the ad 

joining part of the Los Angeles Basin. If it is absent, it 

is improbable that oil is trapped in the Repetto, owing 

to overlap of Pleistocene deposits. If a subsurface 

feature, a fol'd or a fault, corresponding to the Gaffey 

anticline continues southeastward beyond the outcrop 

area of Malaga mudstone, oil may be found in the 

Miocene at or above the schist basement, provided 

suitable reservoir' rocks are present. The record of the 

Hogan wells shows, however, that in at least part of 

this area the subsurface structure is complex. East of 

Gaffey Street the schist basement is estimated to be at 

depths of 5,000 to 6,000 feet below sea level, according 

to subsurface data in the nearby Torrance and Wilming- 

ton fields. 

DIATOMITE 

Diatomite in the upper part of the Valmonte dia- 

tomite member of the Monterey shale is mined by the 

Dicalite Co. in surface and underground workings along 

»' Nicholson, G. F., Variations in level, 1919 to 1927, in Los Angeles Harbor: Seismo- 

logical Soc. America Bull., vol. 19, pp. 200-205, 3 figs., 1929.


the lower course of Agua Negra Canyon and in surface 

workings between Agua Negra Canyon and Crenshaw 

Boulevard. The upper part of the Valmonte of this 

area consists of alternating units of laminated diatomite 

and massive diatomaceous mudstone. Material from 

selected diatomite units is processed in the company's 

plant at the junction of Agua Negra and Valmonte 

Canyons. The product is used fbr filtration, as filler 

for paint, rubber, paper, molded plastics, and other 

products, and for heat insulation. 

The Valmonte diatomite member crops out along the 

north and east slopes of the hills or is inferred to be 

present in those areas beneath a cover of overlapping 

Pleistocene strata. Diatomite of the quality mined is, 

however, not found generally in commercial quantity. 

SAND AND GRAVEL 

Sand and gravel from the lower Pleistocene San 

Pedro sand are mined, washed, and screened at several 

localities along the north border of the hills. The 

Sidebotham plant on Bent Spring Canyon and the 

Richard Ball plant immediately east of Hawthorne 

Avenue are active at the time of writing. At the 

Sidebotham plant the lighter constituents in the gravel 

grades, consisting of limestone, cherty shale, and 

cemented San Pedro sand, are removed by jigging. 

The product consists of granitic and quartzitic pebbles. 

There are extensive deposits of sand and gravel in the 

San Pedro sand along the entire north and northeast 

borders of the hills. 

OTHER PRODUCTS 

Calcareous, material in the Lomita marl was formerly 

mined at Lomita quarry and Hilltop quarry. The 

product is reported to have been used for soil dressing 

and as a source of calcium carbonate for poultry. The 

Lomita. marl has a thickness of as much as 275 feet in 

the Gaffey syncline. 

No. used in 

this report 

1. _.._.__. 

2_. ------- 

2a- -~-- 

2b__- -_~ _ 

3--- -- 

3a---_- _- 

4.-------- 

Permanent 

Geological 

Survey No. 

13123 

Field No. 

B42_ __________ 

B45a ___ ________ 

Wll-31-------- 

W4-33 ________ 

W12-31-____.____ 

B30 _._.__.___.. 

B45 ___________ 

Fossil localities 

Greatly weathered basalt from the Miraleste district 

and Bluff Cove has been used locally as a dressing for 

secondary roads. It appears to bind well, but the 

wearing quality is probably poor. 

Porcelaneous shale, cherty shale, and limestone from 

the Altamira member of the Monterey shale are used 

locally for garden walls and flagstones. In 1940 the 

only active operations were on the coast half a mile 

northwest of Whites Point, where laminated limestone 

concretions are quarried and split. Most of the hard 

Miocene shale in the Palos Verdes Hills is brittle, frac 

tured thin-bedded cherty shale unsuitable for quarry 

ing. Deposits of more thickly bedded pprcelaneous 

shale, such as is quarried in the Monterey district, 28 are 

not extensive. 

FOSSIL LOCALITIES 

In the following list the fossil localities are described, 

and the locality numbers used in this report are corre 

lated with the permanent locality numbers in the 

Cenozoic register of the Geological Survey and with the 

field numbers. The fossil localities described, with the 

exception of a few localities where the maps are con 

gested, are plotted on plates 1, 14, and 21. Locality 

and stratigraphic data for the numbers not plotted are 

sufficient to identify the localities in the field. To 

avoid confusion, the locality numbers for the collections 

of Miocene fossils are the same as those in the pre 

liminary paper. 29 Collections not considered in the 

preliminary paper are intercalated in the numbered 

series by means of letter designations. The units cited 

refer to the units of the geologic section given in other 

parts of the report. 

28 Galliher, E. W., Geology and physical properties of building stone from Carmel 

Valley, Calif.: Mining in California (Div. Mines), vol. 28, No. 1, pp. 21-41, 1932. 

2» Woodring, W. P., Bramlette, M. N., and Kleinpell, R. M., Miocene stratig 

raphy and paleontology of Palos Verdes Hills, Calif.: Am. Assoc. Petroleum 

Geologists Bull., vol. 20, No. 2, pp. 125-149, 1936. 

Description of locality 

MIOCENE 

Lower part of Altamira shale member of Monterey shale 

Portuguese Canyon area, Portuguese Canyon 2,375 feet northwest of 318-foot bench 

mark north of Portuguese Bend. Limy layer in mudstone 110 feet below base of 

Portuguese tuff bed. 

Miraleste area, immediately north of Palos Verdes Drive East, 3,275 feet east-southeast 

of triangulation station on San Pedro Hill. Silty shale underlying basalt sill on 

south limb of Miraleste anticline. 

Bluff Cove area, foot of sea cliff at Bluff Cove, 675 feet northwest of 295-foot bench 

mark on Palos Verdes Drive West near Bluff Cove. Silty shale in almost vertical 

strata on north limb of Bluff Cove anticline. 

Middle part of Altamira shale member of Monterey shale 

Bluff Cove-Malaga Cove area, slope above beach at Bluff Cove, 750 feet north-northeast 

of 295-foot bench mark on Palos Verdes Drive West near Bluff Cove. Saadstone 

on north limb of Bluff Cove anticline about 150 feet stratigraphically below base 

of basalt sill. 

Bluff Cove-Lunada Bay area, Palos Verdes Drive West near Bluff Cove, 1,125 feet 

southwest of 295-fopt bench mark. Limestone a foot above top of basalt sill on south 

limb of Bluff Cove anticline. 

Altamira Canyon-Portuguese Canyon area, east fork of Altamira Canyon, 1,325 feet 

south of 1,215-foot hill south of Crest Road. Limestone 48 feet above probable 

equivalent of Miraleste tuff bed. 

Miraleste-San Pedro Hill area, Crest Road on east slope of San Pedro Hill, 1,250 feet 

southeast of triangulation station on San Pedro Hill. Silty shale.

C 

No. used iu 

this report 

6 

7....-...-. 

S-... ------ 

n 

10.. ------- 

11...-.-- 

12.... .. 

12a__---_- 

12b 

I2c. ------ 

12d 

13-------- 

13a _ .... 

14 ----- 

15 

16------.. 

17---.--.. 

18 

ISa.. ------ 

19-------. 

19a----.-_ 

20-------- 

20a.--_.-_ 

21. ------- 

21a_..---- 

21b--_--.- 

22 

23 .--. 

24---.-.-, 

25..--.--- 

Permanent 

Geological 

Survey No. 

1 

14060 

13127 

13837 

Field No. 

W125-30_. ....... 

W22-33-. ........ 

W21-33.. ........ 

W6-33; SPH-14... 

W61-30----.-.... 

W34-33---------. 

W130-30-_---__-. 

W132-30--------. 

B37.. ............ 

B21._ ......... 

W26-33------ _ _ 

W19-29.---.---.. 

B36... --.-.-.-.. 

'SPH-ll... ....... 

B46_. _------.-... 

B43... ._..-_'__-__ 

W60-30-.--...... 

W2-33-------^--. 

B44 

W24-33--.--.--.. 

W9-35; W38-33; 

W91a-30. 

W39-33-... ---... 

W14-4.. ..__...._ 

W14-5--. .---.--. 

W14-6 

W10-35.---...-.- 

W36-33---------. 

W49-33; SPH 10. _ 

W59-30-------..- 


Fossil localities Continued 

Description of'locality 

MIOCENE Continued 

Middle part of Altamira shale member of Monterey shale Continued 

Miraleste-San Pedro Hill area, branch of San Pedro Canyon east of Miraleste Drive, 

5,350 feet east-southeast of triangulation station on San Pedro Hill. Diatomacepus 

silt, evidently part of soft rocks associated with Miraleste tuff bed. 

San Pedro area, south side of branch of San Pedro Canyon 100 feet west of Weymouth 

St., in block north of Seventh St. Diatomaceous silt containing pebbles and slabs 

of schist. , 

San Pedro area, path in Peck Park on north side of main canyon, 1,175 feet east of 406foot 

hill. Steeply dipping calcareous sandstone. 

Point Fermin area, crest of Point Fermin anticline at foot of sea cliff, 2,000 feet eastnortheast 

of Point Fermin lighthouse. Thin-bedded silty shale interbedded with 

siliceous shale.' 

Point Fermin area, foot of sea cliff at Cabrillo Beach, 50 feet south of Cabrillo fault. 

Massive buff siltstone. 

Bluff Cove-Malaga Cove area, foot of sea cliff 1,450 feet southwest of beach clubhouse 

at Malaga Cove. Granular limestone. 

Miraleste-San Pedro Hill area, ravine near foot of steep slope south of Cabrillo fault, 

8,375 feet southeast of triangulation station on San Pedro Hill. Buff sandstone, 

Point Fermin area, near north end of cut on west side of Alma St., 1,075 feet northeast 

of Thirty-seventh St. Buff siltstone. 

Whites Point area, north limb of fan-shaped fold on east side of Whites Point. Sandstone 

overlying schist conglomerate. (Not plotted on pi. 1.).) 

Whites Point area, low-tide reefs 1.2 miles northwest of Whites Point. Calcareous 

mudstone. 

Whites Point tunnel, station 53+56 feet, 250 feet north of south portal. Mudstone. 

(Not plotted on pi. 1.) 

Whites Point tunnel, station 54+58 feet, 355 feet north of south portal. Mudstone. 


George F Canyon-Miraleste Canyon area, west side of George F Canyon 1,925 feet 

northwest of 732-foot hill near Palos Verdes Drive East. Limy lens in sandstone 

overlying schist, 20 feet above canyon floor. 

George F Canyon-Miraleste Canyon area, west side of first canyon east of Palos Verdes 

Drive East, 2,000 feet southeast of 732-foot hill near Palos Verdes Drive East. Near 

top of sandstone overlying schist. California Inst. Tech. invertebrate locality 348. 

Upper part of Altamjra shale member of Monterey shale 

Point Fermin- Whites Point area, at top of sea cliff along road leading to Whites Point. 

Silty shale. 

Point Fermin- Whites Point area, Dodson Ave. north of Whites Point, 1,000 feet northwest 

of 371-foot bench mark at southwest corner of military reservation. Silty shale 

interbedded with porcelaneous shale. 

Point Fermin- Whites Point area, foot of path leading down to beach on west side of 

Point Fermin, 1,550 feet northwest of Point Fermin lighthouse. Silty shale about 

65 feet below base of upper sandstone unit. 

San Pedro area, Cabrillo Beach, 200 feet north of Cabrillo fault. Silty shale interbedded 

with limestone, porcelaneous shale, and phosphatic shale. 

Valmonte diatomite member of Monterey shale 

San Pedro area, Cabrillo Beach, 300 feet northwest of driveway. Diatomite. (Now 

inaccessible.) 

San Pedro area, Cabrillo Beach, 150 feet south of driveway. Diatomite. 

San Pedro area, Cabrillo Beach, 750 feet northwest of driveway. Diatomite. 

San Pedro area, Cabrillo Beach, 550 feet northwest of driveway. Diatomite. 

San Pedro area, Peck Park, foot of cliff on north side of ravine at north edge of park, 

12 feet above floor of ravine. Diatomite. 

Same locality, 20 feet higher stratigraphically. Diatomite. 

San Pedro area, deep ravine immediately west of Bandini Ave. and east of Peck Park. 

Diatomite 45 feet above base of exposed section. 



San Pedro area, north side of San Pedro Canyon, 100 feet east of Meyler Ave. Diatomite. 

Malaga mudstone member of Monterey shale 

Malaga Cove area, north limb of southern syncline about 30 feet above beach. , Limestone 

concretion 18 feet above bas'e of Malaga mudstone. QSfot plotted on pi. 1.) 

San Pedro area, west side of Cabrillo Ave. 75 feet north of Fourth St. Mudstone. 

San Pedro area, south face of cliff at Timms Point, 100 feet west of point. Limestone 

concretion. (Now inaccessible.) 

121


No. used in 

this report 

26-- 

27 

28- 

30. _._---- 

31. ------- 

32. __----- 

32a_ -_ 

32b 

32c 

32d 

32e_ _ 

33. ------- 

34. __--_-_ 

35 - 

36 - 

37. ------- 

38 

39.. ------ 

40____---_ 

41 

42 - 

42a-._---- 

42b__-_-_- 

42c__ 

42d_--_.-_ 

42e - 

42f_-_---. 

d.9tr 

42h--____ 

42i_______ 

43_ ___ 

43a__ . 

44 _____ 

44a. .--.... 

45 

46 __._ 

47 _ 

Permanent 

Geological 

Survey No. 

13838 

12530 

12529 

12269 

12203 

12214 

12213 

12215 

12204 

12211 

12205 

12212 

12241 

12242 

12210 

12209 

12208 

12239 

12229 

12230 

12231 

12232 

12233 

12234 

12235 

12236 

12237 

12238 

12240 

12247 

12206 

12207 

12216 

12202 

12196 

Field No. 

W19-35-. ----- 

W100-30-----____ 

W50-28-. 

W5-27--_.__. _ 

W7-30__.________ 

W4-30.. .--..... 

W50-30______..__ 

W49-30-__.--_... 

W51-30. ._--._. ._ 

W5-30_________._ 

W47-30-. .. __--__ 

W6-30__-________ 

W48-30________-_ 

W43-30__________ 

W44-30. -.....___ 

W42-30__. _______ 

W39-30-_________ 

W38-30- ____'_____ 

W29-30-. ....-_-_ 

W21-30. -._..__. _ 

W22-30-.. ....__. 

W23-30_-________ 

W24-30-. _. ______ 

W54-30.. __.____. 

W55-30. _________ 

W25-30-. ________ 

W26-30_--_------ 

W56-30._ ________ 

W27-30__. ...__.. 

W30-30.________. 

W62-30_--__-__-_ 

W27a-30-.--_---- 

W28-30_-_..- _ . 

W63-30----.__-_- 

W94-30__l___-.-- 

W2-30. .-__..---- 



PLIOCENE 

Repetto siltstone 

Malaga Cove, south limb and trough of northern syncline. Twenty-five samples from 

lower 85 feet of the Repetto siltstone, each sample representing a thickness of about 

3 feet. ' (Not plotted on pi. 1.) 

Malaga Cove, north limb of northern syncline just north of trough, 5 to 10 feet below 

lower bed of volcanic ash. (Not plotted on pi. 1; see fig. 9.) 

Road leading from Palos Verdes Drive East to prospect excavation in marl, 1,050 feet 

west of 367-foot hill east of Palos Verdes Drive East. 

PLEISTOCENE 

' Lomita marl, Timms Point silt, and San Pedro sand 

Deadman Island, east side. Basal part of San Pedro sand. (Same as California Inst. 

Tech. invertebrate locality 130; not plotted on pi. 1; now inaccessible.) 

Deadman Island, west side. Basal pait of San Pedro sand. (Same as California Inst. 

Tech. invertebrate locality 31; not plotted on pi. 1; now inaccessible.) 

Timms Point. Base of unit 1 of Timms Point silt at point. (Not plotted on pi. 14; 

coincides with geologic boundary; now inaccessible.) 

Timms Point, from point northwestward along bluff to within 50 feet of retaining wall. 

Unit 1 of Timms Point silt. < 

Timms Point, foot of bluff 100 feet south of shanty. Pocket of rich calcareous material 

near base of unit 1 of Timms Point silt. 

Timms Point, foot of bluff from retaining wall to locality 100 feet southeast of retaining 

wall. Unit 1 of Timms Point silt. 

Timms Point, about 175 feet north of point on north and south sides of stairs. Unit 2 

of Timms Point silt. 

Timms Point, at drain pipe about 150 feet southeast of retaining wall. Unit 2 of Timms 

Point silt. 

Timms Point area, east side of Harbor Blvd., 150 feet south of projection of Fourteenth 

St. Unit 2 of Timms Point silt. (Since current edition of Wilmington topographic 

map was issued Harbor Blvd. has been extended from business district of San Pedro 

to Timms Point.) 

Timms Point Area, west side of Harbor Blvd. about 100 feet north of Fourteenth St. 

Unit 1 (?) of Timms Point silt. (See note under locality 33.) 

Timms Point area, west side of Harbor Blvd. about 150 feet north of projection of 

Thirteenth St., along path leading to Beacon St. Timms Point silt. (See note under 

locality 33.) 

Central San Pedro, north side of Eighth St;, 100 feet west of Mesa St. Lomita marl. 

Central San Pedro, south side of alley between Seventh and Eighth Sts., about 150 feet 

west of Mesa St. Lomita marl. 

Central San Pedro, south side of Eighth St., 25 feet east of Center St. Timms Point silt. 

Central San Pedro, east side of Mesa St., 50 feet north of Seventh St., excavation along 

sidewalk. Timms Point silt. 

Central San Pedro, south side of Third St., at southwest corner of Third and Mesa Sts. 

Timms Point silt. 

Central San Pedro, abandoned quarry off alley 150 feet east of Pacific Ave. and 50 feet 

south of Second St. Lomita marl. 

Central San Pedro, south side of Second St., 150 feet east of Pacific Ave. Unit 1 of 

Lomita marl. 

Same locality. Unit 2a of Lomita marl. (Localities 42a to 42i are on progressively 

younger strata and progressively farther east on Second St. between Pacific Ave. and 

Mesa St.,42i being 350 feet east of Pacific Ave. They are not plotted on pi. 14.) 

Same locality. Unit 2b of Lomita marl. 

Same locality Unit 3a of Lomita marl. 

Same locality. Coarse-grained calcareous sand at base of unit 3c of Lomita marl. 

Same locality. Coarse-grained calcareous sand 2 feet 10 inches above base of unit 3c 

of Lomita marl. 

Same locality. A foot above base of unit 4a of Lomita marl. 

Same locality. . 7)4 feet above base of unit 4a of Lomita marl. 


Same locality. 3 feet below top of unit 4b of Lomita marl. 

Central San Pedro, north side of Second St., 150 feet east of Pacific Ave. Coarsegrained 

calcareous sand 6 feet above base of Lomita marl. 

Same locality, 125 feet east of Pacific Ave., and in adjoining alley. Lomita marl. 


Central San Pedro, south side of Second St., 350 feet east of Pacific Ave. Unit 1 of 

Timms Point silt. (Not plotted on pi. 14; coincides with geologic boundary.) 

Same locality. Unit 3 of Timms Point silt. (Not plotted on pi. 14.) 

Central San Pedro, north side of Second St., 150 feet west of Mesa St. Unit 7 of Timms 

Point silt. 

Same locality, 100 feet west of Mesa St. Thin bed of sand 7y2 feet above base of San 

Pedro sand. (Not plotted on pi. 14; coincides with geologic boundary on map of 

that scale.) 

Central San Pedro, west side of Harbor Blvd. at southwest corner of Harbor Blvd. 

and Second St. Unit 3 of San Pedro sand..

No. used in 

this report 

47a.___.__ 

48--.----- 

49.. ...... 

49a_____-- 

50........ 

51-------- 

52. ... _... 

53-...-... 

53a_______ 

53b....... 

54........ 

54a______. 

54b. _ ... 

54c. ...... 

54d-__--_- 

54e-_..... 

54f_____.- 

54g....... 

55........ 

56.......... 

57........ 

57a....... 

58........ 

58a....... 

59........ 

60........ 

60a..._... 

60b....... 

61......... 

62........ 

62a_______ 

62b......_ 

63........ 

64........ 

65........ 

66........ 

67........ 

68........ 

69........ 

70......... 

71........ 

72........ 

72a,....._. 

73........ 

73a....... 

73b....... 

74........ 

Permanent 

Geological 

Survey No. 

12197 

12198 

12628 

12629 

12199 

13777 

12264 

12218 

12220 

12219 

12221 

12222 

12223 

12224 

12225 

12226 

12227 

12228 

12248 

12200 

13803 

13802 

14068 

14069 

12201 

12250 

12251 

12252 

12253 

12245 

12244 

12243 

12455 

12246 

12254 

12217 

12256 

12255 

12263 

12261 

12262 

12259 

12260 

12257 

12258 

12454 

12249 

502787 45- 

Field No. 

W3-30.... ....... 

W65-30... ....... 

Wl-31. _______ __ 

W2-31_____ 

W70-30... ..._.__ 

W4-35 

W140-30________. 

W8-30._._. ______ 

W12-30 

W10-30..... _ . 

W13-30. .. _ 

W14-30.. ________ 

W15-30 

W16-30. __ .. . 

W17-30 . 

W18-30__________ 

W19-30... ._..... 

W20-30... _______ 

W80-30.. .._._.__ 

W83-30.___..___. 

Wl-37.. ..____.__ 

W2-37 ____ __.. 

WR4 3fl 

W99a-30._ ____ 

W99b-30_________ 

wqq/._Qn 

W103-30.. _....._ 

W45b-30__ _______ 

W45a-30...______ 

W45-30__________ 

W144-30. ________ 

W46-30__. ...____ 

W104-30.. ....... 

W105-30.. ....... 

W109-30___....__ 

W108-30.. _______ 

W119-30_.__._._. 

W117-30.. _._.__. 

W118-30_____.._. 

wi 13 3n 

W114-30-_-.-.-_. 

W110-30_--__-___ 

Wlll-30--------. 

W123-30.... _ .. 

W94-30... -._-... 



Description of locality ... 

PLEISTOCENE Continued 

Lomita marl, Tiinms Point silt, and San Pedro sand Continued 

Same locality. Unit 4 of San Pedro sand. 

Northwestern San Pedro, foot of bluff along Harbor Blvd. opposite end of Grand St. 


Gaffey anticline, Harbor Blvd. opposite San Pedro Lumber Co., 4,200 feet northeast of 

intersection of Harbor Blvd. and Pacific Ave. Unit 1 of San Pedro sand. 

Same locality. Unit 3 of San Pedro sand. 

Gaffey anticline, south side of ravine opposite loading platform on siding of Western 

Oil and Refining Co., 2,200 feet southwest of intersection of Harbor Blvd. and Frigate 

Ave. .San Pedro sand. 

Gaffev anticline, abandoned sand pit on west side of Gaffey St., 1,775 feet southwest 

of 151-foot bench mark east of Gaffey St. San Pedro sand. 

Gaffey anticline, ravine west of Gaffey St., 3,150 feet south of intersection of Gaffey 

St. and Anaheim Blvd. Timms Point silt (?). 

Hilltop quarry, algal bed in fault block on southeast face of quarrv. Lomita marl. 

(Localities 53, 53a, and 53b are not plotted on pi. 1, but the quarry is shown.) 

Same locality. Algal bed at level of floor at northwest end of quarry. Lomita marl. 

Same locality. 2-inch shell-bearing lens in marl overlying algal bed on southeast face 

of quarry. Lomita marl. 

Floor and east side of canyon immediately west of Hilltop quarry. Unit 3 of Lomita 

marl. 

Same locality. Unit 4a of Lomita marl. 


Same locality. Unit 5c of Lomita marl. 

Same locality. Unit 5d of Lomita marl. 


Same locality. Unit 6c of Lomita marl. 

Same locality. Unit 7 of Lomita marl. 

West side of canyon immediately west of Hilltop quarry. Lomita marl. 

Standard Oil Co. tank farm, 50 feet inside fence at east boundary. San Pedro sand 

Dump of central shaft of Whites Point tunnel. Probablv from upper 90 feet of Lomita. 

marl penetrated in shaft. 

Whites Point tunnel, 90 feet north of central shaft and 12 feet below sea level. Lomit 

marl. 

Cut on east side of Western Ave., 900 feet south of valley of lower George F Canyon. 

Gray sand at base of cut; San Pedro sand. 

Same locality. Anomia-Ostrea layer in San Pedro sand overlying that at 58. 

Bluff on south side of valley of lower George' F Canyon, 550 feet west of Western Ave. 


Gaffey syncline, prospect pit in calcareous beds 500 feet west of Palos Verdes Drive East. 

Unit 4 of Lomita marl. 

Same localitv. Unit 7 of Lomita marl. 


Gaffey syncline, cut along road above prospect shaft in calcareous beds, 1,500 feet southsoutheast 

of Lomita quarry. Lomita marl. 

Gaffey syncline, Lomita quarry. Unit 2 of Lomita marl. (Not plotted on pi. 1, but 

the quarry is shown.) 



Gaffey syncline, ravine 600 feet northwest of Lomita quarry. San Pedro (?) sand. 

Gaffey anticline, between tank and loading hopper of Sidebotham No. 2 sand pit on 

east side of Bent Spring Canyon 1,625 feet east-northeast of Lomita quarry. San 

Pedro sand. (Not plotted on pi. 1; coincides with geologic boundary.) 

Gaffey anticline, near top of northwest face of Sidebotham No. 1 sand pit on west side 

of Bent Spring Canyon. San Pedro sand. 

North border of hills, ravine 1,000 feet east of Crenshaw Blvd. Timms Point silt. 

North border of hills, southwest face of abandoned gravel pit on east side of Agua Negra 

Canyon. Lomita marl. 

North border of hills, east side of Agua Negra Canyon 500 feet below warehouse of 

Floatstone Products Co. Lomita marl. 

North border of hills, 461-foot hill 800 feet southeast of Hawthorne Ave. Lomita 

marl. 

North border of hills, second ravine northwest of Hawthorne Ave. Lomita marl. 

North border of hills, head of fourth ravine northwest of Hawthorne Ave. Lomita 

marl. 

North border of hills, foot of waterfall in fourth ravine northwest of Hawthorne Ave. 

Lomita marl. 

North border of Mils, southwest face of abandoned sand pit on north side of fourth 

ravine northwest of Hawthorne Ave. Lomita marl. 

North border of hills, foot of waterfall in fifth ravine northwest of Hawthorne Ave. 

Lomita marl. (Not plotted on pi. 21; see fig. 13.) 

Same locality, south side of ravine about 75 feet below waterfall. San Pedro sand. 

(Not plotted on pi. 21; see fig. 13.) 

Same locality, 30 feet upstream from waterfall. Lomita marl. (Not plotted on pi. 

21; see fig. 13.) 

Malaga Cove, upthrown side of northernmost minor fault at north end of cove (pi. 13, A). 

7 feet above base of San Pedro (?) sand. (Not plotted on pi. 1.) 

123


No. used in 

this report 

75 _-_ 

76- ... 

76a_ 

77- 

78 

79- 

80 

81 

82 

.83.: 

84 

85 

86___-_-_- 

87 

88 ------ 

oq 

90 

91- 

92--_--__- 

93 

94 

95 --_-_ 

QR- 

97 

98_____--- 

99 

HHL_____- 

101 

102-_____ 

103 

104_ _ 

105 

106 

107 

108_ _ - 

109 

110 

111 

112 

113 

114 

115 c 

116 

% il7 

Permanent 

Geological 

Survey No. 

13126 

12186 

' 12187 

13137 

12184 

12194 

13136 

12193' 

12182 

13782 

12189 

13135 

13134 

12195 

13796 

13780 

13783 

13784 

13785 

12133 

12190 

13781 

13131 

12185 

13130 

12188 

13132 

13133 

13129 

12191 

12192 

12183 

13125 

12162 

12138 

12137 

13779 

12134 

12132 

12135 

12136 

12148 

12147 

12149 

i 

Field No. ' 

W25-33--.. __---. 

W131a-30 

Wl31b-30-.-_-_-. 

W50-33__-__-_-_- 

Wl24-30i _ . 

W141-30 _1 

W48-33- ----- 

W139-30- __ 

W53-30- _ -- 

W12-35_-_--____ 

W135-30 _ __-- 

W47-33- 

W46-33__-_ -__- 

W142-30- __ _ 

W8-35 __ __ __ 

-W7-35 _ _ 

" W13-35-. _ .. 

W14-35____- ____ 

W15-35_ __ - ___ 

W11-30- _ __ 

W136-30 

Wll-35 __ __ - 

W42-33 

W126-30- __ __ _: _ _ 

W43--33 

W133-30- -_--____ 

W44-33-__-.___. 

W45-33 __ 

W31-33 _. 

W137-30- -. __ 

W138-30 ... 

W122-30- _ _ 

W19-33 

W127-30- :_ . 

W52-30_--.._____ 

W41-30_..--._- 

W6-35 

W35-30- ___, 

Wl-30 _'___ .-_ 

W37-30 ._ 

W40-30__. __"._ _ 

W77-30 

W76-30 

W81-30 




Marine terrace deposits older than Palos Verdes sand 

Southwest slope of San Pedro Hill, Crest Road 1,750 feet southest of triangulation 

station on San Pedro Hill. Twelfth terrace. 

Palos Verdes Drive East, 1,300 feet northeast of intersection of Crest Road, foot of cut. 

Ninth terrace. ^ 

Same locality, top of cut 50 feet to southwest. Ninth terrace. 

Palos Verdes Drive East, Miraleste district, 900 feet northwest of intersection of Miraleste 

Drive. Eighth terrace. . 

Miraleste district, Colinta Road, "300 feet southwest of intersection of Miraleste Drive. 

Sixth terrace. 

Malaga Cove district, Del Monte Road, 500 feet southwest of La Venta Inn. Sixth 

terrace. ' s 

Crest Road, 2,550 feet northeast of Point Vicente lighthouse. Fifth terrace. 

Malaga Cove district, Montemar Road, 1,125 feet southeast of 278-foot bench mark near 

Flatrock Point. Fifth terrace. 

Southern San Pedro, west side of Peck St., 375 feet north of Thirty-sixth St. Fourth 

terrace. , 

Southern San Pedro, west side of Gaffey St., 50 feet north of Thirty-eighth St. Fourth 

terrace. 

Palos Verdes Drive South, 1,950 feet east-northeast of Point Vicente lighthouse, about 

50 feet above level of highway. Fourth terrace. 

Palos Verdes Drive West, 1,050 feet east of 157-foot bench mark between Resort Point 

and Point Vicente. Fourth terrace. 

Bluff Cove, near top of sea cliff 475 feet north of 295-foot bench mark. Fourth terrace. 

Malaga Cove district, Campesina Road at intersection of Segunda Road. Fourth terrace. 

, 

Palos Verdes Drive North, 4,400 feet southeast of Palos Verdes Golf Club. Fourth 

terrace. v 

Palos Verdes Drive North, 3,500 feet west-southwest of intersection of Palos Verdes Drive 

East. Fourth terrace. 

Southern San Pedro, west side of Gaffey St., 100 feet north of Thirty-first St. Third 

terrace. . ' > 

Southern San Pedro, south side of Hamilton Place, 100 feet southeast of Gaffey St. 

Third terrace. 

Southern San Pedro, south side of Twenty-first St., 200 feet west of Cabrillo St. Third 

terrace. 

Southwest face of Hilltop quarry. Third terrace. (Not plotted on pi. 1 ; coincides with 

geologic boundary at southeast end of quarry.) 

Southern San Pedro, top of sea cliff 950 feet northwest of Point Fermin lighthouse. 

.Second terrace. (Chaces' chiton bed locality.) 

Southern San Pedro, west side of Gaffey St., 100 feet north of Thirty-ninth St. Nonmarine 

cover banked against cliff at rear of second terrace. 

South coast, 3,600 feet northwest of Point Fermin lighthouse. Second terrace. 

. Southwestern San Pedro, north side of Thirty-seventh St., 225 feet east of Averill St. 

Nonmarine cover banked against cliff at rear of second terrace. . 

South coast, 2,800 feet northwest of Whites Point. Second terrace. 

South coast, Portuguese Bend, 3,500 feet east of Inspiration Point. Second terrace.' 

South coast, 3,600 feet northeast of triangulation station at Long Point. Second terrace. 

West coast, 3,750 feet northwest of Point Vicente lighthouse. Second terrace. 

West coast, Lunada Bay, south side of Agua Amarga Canyon. Second terrace. 

Same locality, north side of Agua Amarga Canyon. Second terrace. 

West coast, near Flatrock Point. Second terrace. 

Malaga Cove district, Corta Road 900 feet northwest of Malaga Cove business district. 

Second terrace. 

Northwestern San Pedro, path in Peck Park 650 feet south-southeast of 252-foot hill. 

Second terrace. 


San" Pedro, Cabrillo Beach, 500 feet northwest of driveway. 

San Pedro, north side of ravine at north edge of Fort McArthur Lower Reservation. 

(Arnold's Crawfish George's locality.) - 

San Pedro, vacant lot near northwest corner of Palos Verdes and Eighth Sts. (Now infLCCGSSlfolG 

1 ' ' 

San Pedro, west side of Mesa St., 100 feet south of Third St. 

San Pedro, east side of Palos Verdes St., 75 feet north of Third St. 

Sari Pedro, west side of Pacific Ave., midway between Oliver and Bonita Sts. 

San Pedro, east side of 48-foot mesa, 1,000 feet southeast of intersection of Harbor 

Blvd. and Pacific Electric tracks. (Arnold's lumber yard locality; now inaccessible.) 

San Pedro, south side of Harbor Blvd. immediately south of crossing of Pacific Electric 

tracks. - 

San Pedro, north side of street leading westward from Gaffey St., at north edge of town, 

1,000 feet west of Gaffey St. 

South limb of Gaffey syncline, 3,200 feet northwest of intersection of Harbor Blvd. 

and Pacific Ave. ' 

South limb of Gaffey syncline, cattle trail 50 feet south of fence at south boundary of 

Standard Oil Co. tank farm.

No. used in 

this report 

118_._____ 

119_______ 

120_._..__ 

121. ______ 

122 __ __ 

123_______ 

124_______ 

125_______ 

126 _ - _ 

127. ._ _ 

128__ ____ 

129_______ 

130_______ 

131_______ 

132 _ ___ 

133_._____ 

134_______ 

135-. . 

136_______ 

137_______ 

138_______ 

139_._____ 

139a_:.____ 

139b______ 

140. _ __ 

141-______ 

142. __ 

Permanent 

Geological 

Survey No. 

12150 

12140 

12141 

12142 

12139 

12146 

12145 

12152 

12163 

12154 

12153 

-12143 

12144 

12151 

12155 

13786- 

13778 

12156 

12157 

13776 

12158 

13774 

13775 

12159 

12631 

12162 

12160 

Field No. 

W82-30____._____ 

W66-30_ _________ 

W68-30__________ 

W69-30__________ 

W67-30__________ 

W74-30__________ 

W73-30__________ 

W87-30__________ 

W128-30_________ 

W89-30__________ 

W88-30__________ 

W71-30___. ______ 

W72-30______.___ 

W86-30___.______ 

W90-30__________ 

W16-35__ _______ 

W5-35-.__-A____ 

W98-30__________ 

W101-30_________ 

W3-35-_--l______ 

W102-3Q_________ 

Wl-35_--_-._____ 

W2-35___________ 

W107-30_________ 

W21-31__________ 

W116-30. ____ __ 

W112-30__ __ ___ 



\ ' , 



Palos Verdes sand Continued 

South limb of Gaffey syncline, road in Standard Oil Co. tank farm, 350 feet west of 

fence at east boundary. 

Gaffey syncline, Harbor Blvd. 2,200 feet north-northwest of intersection of Harbor Blvd. 

and Pacific Ave. 

Gaffey anticline, Harbor Blvd. opposite San Pedro Lumber Co., 4,300 feet northeast 

of intersection of Harbor Blvd. and Pacific Ave. 

Gaffey anticline, south side of ravine along siding of Western Oil and Refining Co. 

immediately west of Harbor Blvd., 2,150 feet southwest of intersection of Harbor 

Blvd. and Frigate Ave. 

Gaffey anticline, ravine on east side of valley along Gaffey St., 3,500 feet north-northwest 

of intersection of Harbor Blvd., and Pacific Ave. 

Gaffey anticline, east side of valley along Gaffey St., 300 feet south of Anaheim Blvd. 

Gaffey anticline, east side of valley along Gaffey St., immediately north of Anaheim 

Blvd. 

Gaffey anticline, ravine on north side of valley of lower George F Canyon, 4,650 feet 

south-southwest of intersection of Anaheim Blvd. and Gaffey St. 

Gaffey anticline, ravine on west side of valley along Gaffey St., 4,800 feet south of 

intersection of Anaheim Blvd. and Gaffey St. 

, Gaffey anticline, abandoned sand pit on west side of valley along Gaffey St., 3,600 feet 

south of intersection of Anaheim Blvd. and Gaffey St. 

Gaffey anticline, ravine on west side of valley along Gaffey St., 900 feet southwest of 

intersection of Anaheim Blvd. and Gaffey St. 

Gaffey anticline, west side of Gaffey St., 350 feet southeast of Anaheim Blvd. Isolated 

pocket of Palos Verdes sand 3 feet below top of San Pedro sand. 

Gaffey anticline, south side of Anaheim Blvd. 300 feet southeast of bridge across Pacific 

Electric tracks. (Area of Palos Verdes sand exposed in cut too small to show on 

pi. 1.) 

Gaffey anticline, north side of valley of lower George F Canyon, 1,150 feet west of 

Western Ave. 

Gaffey anticline, ravine on north side of valley of lower George F Canyon, 1,100 feet west 

of Western Ave. 

West side of Palos Verdes Drive East 800 feet south of intersection with Palos Verdes 

Drive North. Palos Verdes (?) sand. (Now inaccessible.) 

Gaffey anticline, west side of Palos Verdes Drive North 450 feet southwest of Anaheim 

Blvd. 

Gaffey anticline, east side of ravine near head of Senator St., 1,400 feet west-southwest 

of intersection of Anaheim Blvd. and Palos Verdes Drive North. 

Gaffey anticline, head of ravine 1,100 feet southeast of Bent Spring Canyon. 

Gaffey anticline, near head of ravine 500 feet southeast of Bent Spring Canyon. 

Gaffey anticline, cut on west side of Cypress St., Lomita, opposite settling basin of 

waterworks. (Area of Palos Verdes sand exposed in cut too small to show on pi. 1.) 

North border Of hills, east face of first sand pit (Graham Bros.) .west of Agua Magna 

Canyon. Top of basal gravel of Palos Verdes sand. 

Same locality. Top of upper gravel of Palos Verdes sand. 

Same locality, 200 feet to southwest. Upper gravel of Palos Verdes sand. 

North border of hills, cut at workings of Dicalite Co., 300 feet east of Agua Negra Canyon. 

North border of hills, Hawthorne Ave. 

North border of hills, fifth ravine northwest of Hawthorne Ave. Upper gravel of Palos 

Verdes sand. (Not shown on-pl. 21; see fig. 13.) 

125

G92787 45 10 

PLATES 28-37 

127

PLATE 28 

[Specimens from locality 13 unless otherwise designated] 

FIGURE .1. Turritella ocoyana Conrad. Guttapercha squeeze, small specimen. Length (incomplete) about 13 mm, width 7 mm. 

U. S. Nat. Mus. 497069. 

2. Turritella ocoyana Conrad. Guttapercha squeeze, small specimen. Length (incomplete) about 21 mm., width about 

6 mm. U. S. Nat. Mus. 497070. 

3. Strombus cf. S. gatunensis Toula. Guttapercha squeeze. Length (incomplete) about 19 mm. width about 9.5 mm. 

U. S. Nat. Mus. 497071. 

4. Strombus cf. S. gatunensis Toula. Guttapercha squeeze. Length (incomplete) about 11.5 mm. width about 9 mm. 

TJ. S. Nat. Mus. 497072. 

5. "Phos" dumbleanus Anderson. Guttapercha squeeze. Length (incomplete) about 7.5 mm., width about 4.5 mm. U. S. 

Nat. Mus. 497075. 

6. "Phos" dumbleanus Anderson. Guttapercha squeeze. Length (incomplete) about 11.5 mm., width 6 mm. U. S. Nat. 

Mus. 497074. 

7. Anachis (Costoanachis) sp. Guttapercha squeeze. Length (almost complete) 5 mm., width 2 mm. U. S. Nat. Mus. 

497073. 

8. Cancellaria cf. C. condoni Anderson. Guttapercha squeeze. Length (incomplete) about 17 mm., width about 17 mm. 

U. S. Nat. Mus. 497076. 

9. "Clavatula" cf. "C." labiata (Gabb). Guttapercha squeeze. Length (incomplete) about 17 mm., width 8.3 mm. 

U. S. Nat. Mus. 497080. 

10. Aequipecten cf. A. sancti-ludovici (Anderson and Martin). Guttapercha squeeze, right valve. Length about 23 mm., 

height about 22 mm. U. S. Nat. Mus. 497082. 

11. Aequipecten andersoni (Arnold). Guttapercha squeeze, small right valve. Length 12.5 mm., height 11 mm. U. S. 

Nat. Mus. 497081. Locality 2b. 

12. Crassinella cf. C. mexicana Pilsbry and Lowe. Right valve. Length 2.5 mm., height 2.3 mm. U. S. Nat. Mus. 497083. 

13. Knefastia cf. K. funiculata (Valenciennes). Guttapercha squeeze. Length (almost complete) about 41 mm., width 

14.5 mm. U. S. Nat. Mus. 497079. 

14. Conus owenianus Anderson. Guttapercha squeeze. Length (almost complete) about 15.5 mm., width about 9.8 mm. 

U. S. Nat. Mus. 497078. 

15. Conus owenianus Anderson. Guttapercha squeeze. Length (virtually complete) 15 mm., width 9.8 mm. U. S. Nat. 

Mus. 497077. 

16. Miltha sanctaecrucis Arnold. Guttapercha squeeze, left valve. Length 50 mm., height about 47 mm. U. S. Nat. 

Mus. 497087. 

17. Divaricella cf. D. eburnea (Reeve). Internal mold, right valve. Length 15.8 mm.j height 15.5 mm. U. S. Nat. Mus. 

497084. 

18. Dosinia aff. D. ponderosa (Gray). Guttapercha squeeze, left valve. Length (incomplete) 32 mm., height (incomplete) 

23 mm. U. S. Nat. Mus. 497090. 

19. Macrocallista cf. M. maculata (Linne"). Internal mold, right valve. Length (almost complete) 41.2 mm., height 27.8 

mm. U. S. Nat. Mus. 497091. 

20. Divaricella cf. D. eburnea (Reeve). Guttapercha squeeze, right valve. Length (incomplete) 9 mm., height 10 mm. 

U. S. Nat. Mus. 497086. 

21. Divaricella cf. D. eburnea (Reeve). Guttapercha squeeze, left valve. Length 15.5 mm., height about 15.5 mm. U. S. 

Nat. Mus. 497085. 

22. Dosinia aff. D. ponderosa (Gray). Internal mold, right valve. Length (almost complete) 48 mm., height about 44 mm. 

U. S. Nat. Mus. 497089. 

23. Chione (Lirophora) aff. C. mariae (d'Orbigny). Guttapercha squeeze, left valve. Length 26 mm., height 19 mm. 

U. S. Nat. Mus. 497088. 

24. Trigoniocardia aff. T. antillarum (d'Orbigny). Internal mold, right valve. Length 9.9 mm., height 9.7 mm. U. S. 

Nat. Mus. 497092. 

25. Trigoniocardia aff. T. antillarum (d'Orbigny). Guttapercha squeeze, right valve. Length (incomplete) 5.5 mm., height' 

(incomplete) 5.5 mm. U. S. Nat. Mus. 497093. 

128

GEOLOGICAL SUEVEY PROFESSIONAL PAPER 207 PLATE 28 

22 L "" 23 24 x4 

MIOCENE MOLLUSKS FROM MIDDLE PART OF ALTAMIRA MEMBER OF MONTEREY SHALE.


26 25 27 

PLEISTOCENE MOLLUSKS FROM LOMITA MARL.

PLATE 29 

[Species and varieties illustrated are still living unless otherwise specified] 

FIGURE 1. Puncturella cooperi Carpenter. Length 6.8 mm., width 5.6 mm., height 4.5 mm. U. S. Nat. Mus. 498562. Locality 

54g. Found also in Timms Point silt and San Pedro sand. 

2. Puncturella delosi Arnold. Length 2.5 mm., width 1.8 mm., height 2.3 mm. ' U. S. Nat. Mus. 498563. Locality 54g. 

Found also in Timms Point silt and San Pedro sand. 

3-5. Vitrinella salvania Dall. Length 1.1 mm., width 1.9 mm. U. S. Nat. Mus. 498564. Locality 41. 

6-7. Pomaulax undosus (Wood). Length 44.5 mm., width 54.5 mm. U. S. Nat. Mus. 498565. Locality 53a. Found also 

in Timms Point silt, marine deposits on twelfth (identification doubtful), ninth, fourth, and second terraces, and 

Palos Verdes sand. 

S. Pomaulax undosus (Wood). Operculum. Length 24 mm., height 31.7 mm. U. S. Nat. Mus. 498566. Locality 53a. 

9, 10. Pomaulax t'lirbanicus petrothauma (Berry). Length 26.7 mm., width 30 mm. U. S. Nat. Mus. 498567. Locality 53a. 

Not known to be living. 

11. Pomaulax turbanicus petrothauma (Berry). Length 32.5 mm., width (incomplete) 36 mm. U. S. Nat. Mus. 498568. 

Locality 53a. 

12. Pomaulax turbanicus petrothauma (Berry). Operculum. Length 24.8 mm., height 29.6 mm. U. S. Nat. Mus. 498569. 

Locality 53a. 

.1.3, 14. Pachypoma gibberosum (Dillwyn). Length (not quite complete) 40 mm., width 43.5 mm. U. S. Nat. Mus. 498570. 

Locality 53a. Found also in Timms Point silt and San Pedro sand, and reported from Palos Verdes sand. 

15. Pachypoma gibberosum. (Dillwyn). Operculum. Length 14 mm., height 23 mm. U. S. Nat: Mus. 498571. Locality 

53a. 

16. Homalopoma carpenteri (Pilsbry). Length 7.8 mm., width 8 mm. U. S. Nat. Mus. 498572. Locality 53a. Found 

also in Timms Point silt, San Pedro sand, marine deposits on twelfth, ninth, and fifth to second terraces, inclusive, 

and Palos Verdes sand. 

17. Rissoina kelseyi Dall and Bartsch. Length 5 mm., width 1.9 mm. U. S. Nat. Mus. 498573. Locality 53a. Found 

also in marine deposits on second terrace. 

18. Rissoina coronadoensis Bartsch. Length 2.8 mm., width 1.2 mm. U. S. Nat. Mus. 498574. Locality 42d. Found also 

in Timms Point silt and San Pedro sand. 

19. Bittium rugatiim Carpenter. Length 11.8 mm., width 4.3 mm. U. S. Nat. Mus. 498575. Locality 37. Found also in 

Timms Point silt, San Pedro sand, and Palos Verdes sand. 

20. Bittium rugatum larum Bartsch. Length 10 mm., width 3 mm. U. S. Nat. Mus. 498576. Locality 37. Found also 

in Timms Point silt, San Pedro sand, and marine deposits on fourth terrace. 

21. Elassitm californicum (Dall and Bartsch). Length 5 mm., width 1.9 mm. U. S. Nat. Mus. 498577. Locality 53b. 

Found also in Timms Point silt and San Pedro sand. Genus not known to be living. 

22. Turritelia pedroensis Applin. Heavily sculptured form. Length (incomplete) 56 mm., width 24 mm. U. S. Nat. Mus. 

498578. Locality 57. Found also in Timms Point silt, San Pedro sand, marine deposits on third terrace, and Palos 

Verdes sand. Not known to be living. 

23. Turritelta pedroensis Applin. Length (not quite complete) 66 mm., width 18.5 mm. U. S. Nat. Mus. 498579. Locality 

73. 

24. Crepipatella charybdis (Berry). Length 14.3 mm,, width 12.4 mm., height 4.2 mm. U. S. Nat. Mus. 498580. Locality 

67. Found also in Timms Point silt and San Pedro sand. 

25. Bursa californica (Hinds). Length 84 mm., width 53 mm. U. S. Nat. Mus. 498581. Locality 53a. Found also in 

marine deposits on third terrace (identification doubtful) and Palos Verdes sand. 

26. Harfordia monksae (Dall). Length (not quite complete) 43.7 mm., width 18.5 mm. U. S. Nat. Mus. 498582. Locality 

53a. Found also in marine deposits on fifth (identification doubtful), fourth, and second terraces, and Palos Verdes 

sand. 

27. "Nassa" insculvta (Carpenter). Length 18.8 mm., width 11.4 mm. U. S. Nat. Mus. 498583. Locality 53a. Reported 

from Palos Verdes sand. 

28. Calicantharus fortis (Carpenter). Length (not quite complete) 50.5 mm., width 30 mm. -U. S. Nat. Mus. 498584. 

Locality 53. Found also in San Pedro sand and reported from Timms Point silt and Palos Verdes sand. Genus not 

known to be living. 

29. Calicantharus fortis (Carpenter). Strongly sculptured form. Length (not quite complete) 48 mm., width 28 mm. 

U. S. Nat. Mus. 498585. Locality 57. 

129

PLATE 30 


FIGURE 1. Jaton gemma (Sowerby). Length 30 mm., width 20 mm. U. S. Nat. Mus. 498586. Locality 53a. Found also in 

marine deposits on fourth and third terraces. 

2. Tritonalia coryphaena Woodring, n. sp. Type. Length (almost complete) 34.3 mm., width 20.5 mm. U. S. Nat. Mus. 

498587. Locality 53a. Not known to be living. 

3. Erato vitellina Hinds. Length 16 mm., width 10.5 mm. U. S. Nat. Mus. 498588. Locality 57. 

4. Acteon breviculus Dall. Length 5.3 mm., width 3.4 mm. U. S. Nat. Mus. 498589. Locality 54g. 

5, 6. Glycymeris profunda (Dall). Partly corroded right valve. Length 22.4 mm., height 22 mm., diameter 7.6 mm. U. S. 

Nat. Mus. 498590. Locality 53a. Found also in San Pedro sand and reported apparently from Palos Verdes sand. 

7, 8. Glycymeris profunda (Dall). Uncorroded left valve. Length 19.7 mm., height 19.2 mm., diameter 8 mm. U. S. Nat. 

Mus. 498591. Locality 73. 

9, 10. Pecten stearnsii Dall. Large left valve. Length 108.5 mm., height 93.5 mm., diameter about 6 mm. Calif. Inst. Tech. 

3417. Calif. Inst. Tech. locality 107 (same as locality 53 of this report). Found also in Timms Point silt and San 

Pedro sand (identification doubtful). Not known to be living. 

11. Ostrea m.egodon cerrosensis (Gabb). Right valve. Length 79.5 mm., height 49 mm., diameter 18 mm. U. S. Nat. Mus. 

498592. Locality 61. Not known to be living. 

130


X 2 

11 

1'LEISTOCENE MOLLUSKS FROM LOMITA MARL.


PLEISTOCENE MOLLUSKS FROM LOMITA MARL.

PLATE 31 

[Species and varieties illustrated arc still living unless otherwise specified] 

FIGURES 1, 2. Eucrassatella fluctuata (Carpenter). Large, thick-shelled corroded left valve. Length 41 mm., height 37!5 mm., 

diameter 11.5 mm. U. S. Nat. Mus. 498593. Locality 53a. Found also in Timms Point silt and San Pedro sand 

(identification doubtful). 

3, 4. Eucrassatella fluctuata (Carpenter). Small right valve similar to type. Length 6.6 mm., height 5 mm., diameter 

1 mm. U. S. Nat. Mus. 498594. Locality 53a. 

5, 6. Eucrassatella fluctuata (Carpenter): Large right valve. Length 39.8 mm., height 32 mm., diameter 9 mm. U. S. 

Nat. Mus. 498595. Locality 54g. 

7, 8. Eucrassatella fluctuata (Carpenter). Small left valve. Length 21.7 mm., height 18.3 mm., diameter 5 mm. U. S. 

Nat. Mus. 498596. Locality 54g. 

9. Cyclocardia aff. C. occidentalis (Conrad). Large right valve. Length 30.3 mm., height 28.9 mm., diameter 8.7 mm. 

U. S. Nat. Mus. 498597. Locality 53a. Found also in Timms Point silt, San Pedro sand, and Palos Verdes sand. 

10. Cyclocardia aff.. C. occidentalis (Conrad). Moderately large left valve. Length 26.2 mm., height 24.1 mm., diameter 

9.7 mm. U. S. Nat. Mus. 498598. Locality 71. 

.11. Cyclocardia barbarensis (Stearns). Elongate strongly inflated left valve. Length 16 mm., height 15.5 mm., diameter 

6.3 mm. U. S. Nat. Mus. 498599. Locality 54e. Reported from Timms Point silt, San Pedro sand, and Palos 

Verdes sand. 

12. Cyclocardia barbarensis (Stearns). Short right valve. Length 17.7 mm., height 16.6 mm., diameter 5.5 mm. 

U. S. Nat. Mus. 498600. Locality 54e. 

13, 14. Ventricola fordii (Yates). Left-valve. Length 70 mm., height 65 mm., diameter 28 mm. U. S. Nat. Mus. 498601. 

Locality 53a. 

15. Ventricola fordii (Yates). Right valve. Length 50 mm., height 48.5 mm., diameter 19.7 mm. U. S. Nat. Mus. 

498602. Locality 53a. 

16, 17. Mercenaria perlaminosa (Conrad). Right valve. Length 67 mm., height (incomplete) 53 mm., diameter 18 mm. 

Calif. Inst. Tech. 3414. Calif. Inst. Tech. locality 316 (same as locality 53 of this report). Found also in Timms 

Point silt. Not known to be living. 

131

PLATE 32 


FIGURE 1. Turcica caffea (Gabb). Length 23.6 mm., width 18.5 mm. TJ. S. Nat. Mus. 498603. Locality 32a. Reported also 

from San Pedro sand. 

2. Turcica caffea (Gabb). Length 17.3 mm., width 15.2 mm. U. S. Nat. Mus. 498604. Locality 32c. 

3. Solariella peramabilis Carpenter. Length 12.8 mm., width 13.7 mm. U. S. Nat. Mus. 498605. Locality 32d. Found 

also in Lomita marl. 

4. Turritella pedroensis Appliu. Length (not quite complete) 63.7 mm., width 17.5 mm. U. S. Nat. Mus. 498606. Locality 

66. Found also in Lomita marl, San Pedro sand, deposits on third terrace, and Palos Verdes sand. Not known to 

be living. 

5, 6. Crepidula princeps Conrad, small var. Length (not quite complete) 55 mm., width 40.5 mm., height 23 mm. Calif. 

Inst. Tech. 3413. Calif. lust. Tech. locality 136 (Timms Point). Reported also from Palos Verdes sand. Not known 

to be living. 

7. Crepipatella charybdis (Berry). Length 10.6 mm., width 11.5 mm., height 3.4 mm. U. S. Nat. Mus. 498607. Locality 

32c. Found also in Lomita marl and San Pedro sand. 

8. Crepipatella charybdis (Berry). Length 5.3 mm., width 4.9 mm., height 2.3 mm. U. S. Nat. Mus. 498608. Locality 32c. 

9. Fusitriton oregonensis (Redfield). Length (incomplete) 47 mm., width 26 mm. XI. S. Nat. Mus. 498609. Locality 32c. 

Found also in Lomita marl and Palos Verdes sand, and reported from San Pedro sand. 

10. Barbarofusus cf. B. arnoldi (Cossmann). Length 51.3 mm., width 18.5 mm. U. S. Nat. Mus. 498610. Locality 32c. 

11. Neptunea tabulata (Baird). Length 70.3 mm., width 30.5 mm. U. S. Nat. Mus. 498611. Locality 32c. Found also 

in Lomita marl and San Pedro sand. 

12. Exilioidea rectirostris (Carpenter). Length (not quite complete) 24 mm., width 16.3 mm. U. S. Nat. Mus. 498612. 

Locality 32c. Found also in Palos Verdes sand and reported from San Pedro sand. 

13. Mitrella carinata gausapata (Gould). Length 10.2 mm., width 4.7 mm. U. S. Nat. Mus. 498613. Locality 32c. Found 

also in Lomita marl, San Pedro sand, in deposits on fourth and second terraces, and Palos Verdes sand. 

14,15. Pecten stearnsii Dall. Small right valve. Length 47.8 mm., height 43.6 mm., diameter 10 mm. U. S. Nat. Mus. 498614. 

Locality 32c. Found also in Lomita marl and San Pedro sand (identification doubtful). Not known to be living. 

16. Chlamys islandicus jordani (Arnold). Exceptionally large right valve. Length 53.5 mm., height 53.7 mm., diameter 9 

mm. U. S. Nat. Mus. 498617. Locality 32a. Found also in Lomita marl and San Pedro sand. 

17. Patinopecten caurinus (Gould). Large left valve. Length 141 mm., height (almost complete) 139 mm., diameter 11 mm. 

U. S. Nat. Mus. 498615. U. S. Geol. Survey locality 7333, Deadman Island. Found also in Lomita marl and San 

Pedro sand. 

132


13 12 ^W-«^^V 17 

PLEISTOCENE MOLLUSKS FROM TIMMS POINT SILT.

GEOLOGICAL SUBVEY PROFESSIONAL PAPER 207 PLATE 33 

PLEISTOCENE MOLLUSKS FROM TIMMS POINT SILTi

PLATE 33 


1. Patinopecten caurinus (Gould). Small right valve. Length 49.5 mm., height 49 mm., diameter 5 mm. U. S. Nat. 

. Mus. 498616. Locality 32c. Found also in Lomita marl and San Pedro sand. 

2. Hynlopecten vancouverensis (Whiteaves). Right valve with weak radial sculpture. Length 7.2 mm., height 7.1 mm. 

U. S. Nat. Mus. 498618. Locality 32c. Found also in Lomita marl. 

3. Hyalopecten vancouverensis (Whiteaves). Right valve with strong radial sculpture. Length 5.9 mm., height 5.7 mm. 


4. Cydocardia aff. C. occidenlalis (Conrad). Strongly noded form similar to C. californica (Dall), right valve. Length 

18.7 mm., height 17.7 mm., diameter 8.2 mm. U. S. Nat. Mus. 498620. Locality 66. Found also in Lomita marl 

and San Pedro sand. 

5. Thyasiia disjuncta (Gabb). Left valve of paired specimen. Length 82 mm., height 68 mm., diameter (both valves) 

48.5 mm. U. S. Nat. Mus. 498621. U. S. Geol. Survey locality 2481, Deadman Island. 

6. Macoma calcarea (Gmelin), small var. Left valve. Length 25.6 mm., height 18.9 mm., diameter 4.3 mm. U. S. Nat. 


7, S. Kathcrinella subdiaphana (Carpenter). Right valve. Length 49.5 mm., height 39.5 mm., diameter 13.5 mm. U. S. 

Nat. Mus. 498623. Locality 40. Found also in Lomita marl and San Pedro sand. 

9. Katherinella subdiaphana (Carpenter). Left valve. Length (incomplete) 32 mm., height 30.5 mm., diameter 10.2 mm. 


10, 11. Pralulum centifdosum (Carpenter). Left valve. Length 24.9 mm., height 22.8 mm., diameter 8 mm. U. S. Nat. Mus. 

498625. Locality 32a. Found also in Lomita marl and San Pedro sand. 

12. Mya truncata Linn'6. Right valve. Length 50 mm., height 33.7 mm., diameter 10.7 mm. U. S. Nat. Mus. 498626. 

Locality 45. 

13. Panomya beringianus Dall, small var. Left valve. Length 58.7 mm., height 42.8mm., diameter 11.8 mm. Calif. Inst. 

Tech 3416. Calif. Inst. Tech. Locality 78, Timms Point. 

14. Panomya berinqianus Dall, small var. Left valve of sheared paired specimen. Length 47.5 mm., height 33.5 mm. 

U. S.' Nat. Mus. 498627. Locality 44a. 

15. Thracia trapezoides Conrad. Right valve of paired specimen. Length 57.8 mm., height 42.7 mm., diameter (both valves) 

18.3 mm. Calif. Inst. Tech. 3415. Calif. Inst. Tech. locality 320, Timms Point. Found also in Lomita marl. 

16, 17. Pandora grandis Dall. Right valve. Length (incomplete) 35.5 mm., height 32.8 mm., diameter 3 mm. U. S. Nat. Mus. 

498628. Locality 44. 

18. Pandora qrandfs Dall. Left valve of paired specimen. Length 33 mm., height 26.5 mm., diameter (both valves) 7.7 mm. 

Calif. Inst. Tech. 3412. Calif Inst. Tech. locality 77, Timms Point. 

133

PLATE 34 


FIGURES 1, 2. Acmaea funiculata (Carpenter). Small form. Length 6.3 mm., width 5.5 mm., height 3.7 mm. U. S. Nat. Mus 

498629. Locality 30. Found also in Lomita marl and Timms Point silt. 

3. Pupillaria optabilis knechti (Arnold). Length 8.3 mm., width 7.7 mm. U. S. Nat. Mus. 498630. Locality 47a. 

Found also in Palos Verdes sand. Recently reported to be living at Forrester Island, Alaska. 

4. Pupillaria optabilis knechti (Arnold). Length 6.3 mm., width 6.2 mm. U. S. Nat. Mus. 498631. Locality 47a. 

5. Iselica fenestrata (Carpenter). Length 8 mm., width 5.2 mm. U. S. Nat. Mus. 498632. Locality 47a. Found also 

in Lomita marl, deposits on second terrace, and Palos Verdes sand. 

6. Bittium armillatum Carpenter. Length 12 mm., width 3.9 mm. U. S. Nat. Mus. 498633. Locality 47a. Found 

also in Lomita marl, Timms Point silt, in deposits on twelfth, ninth, sixth (identification doubtful), and fifth to second 

(inclusive) terraces, and in Palos Verdes sand. B. armillatum proper is not known to be living. 

7. Turritella pedroensis Applin. Length (not quite complete) 56 mm., width 15.7 mm. U. S. Nat. Mus. 498634. 

Locality 30. Found also in Lomita marl, Timms Point silt, deposits on third terrace, and Palos Verdes sand. Not 

known to be living. 

8. Turritella cooperi Carpenter. Length 46.8 mm., width 12.3 mm. U. S. Nat. Mus. 498635. Locality 30. Found 

also in Lomita marl, Timms Point silt, and Palos Verdes sand. 

9. Barbarofusus barbarensis (Trask) of Arnold. Length 71.7 mm., width 25 mm.. U. S. Nat. Mus. 498636. Locality 30. 

Found also in Lomita marl and Timms Point silt and reported from Palos Verdes sand. 

10. Barbarofusus arnoldi (Cossmann). Neotype. Length 65.3 mm., width 27 mm. U. S. Nat. Mus. 498637. Locality 

30. Found also in Timms Point silt (identification doubtful) and Palos Verdes sand. 

11. Barbarofusus arnoldi (Cossmann). Length 42.2 mm., width 18 mm. U. S. Nat. Mus. 498638. Locality 30. 

12. " Nassa" mendica cooperi Forbes. Length 15.5 mm., width 7.8mm. U. S. Nat. Mus. 498639. Locality 30. Found 

also in Lomita marl, Timms Point silt, deposits on twelfth (identification doubtful) and sixth to second (inclusive) 

terraces, and in Palos Verdes sand. 

13. Tritonalia squamidifera (Carpenter). Length 34.6 mm., width 18 mm. U. S. Nat. Mus. 498640. Locality 30. 

14. Trophonopsis lasia (Dall). Length (almost complete) 27.2 mm., width 14 mm. U. S. Nat Mus. 498641. Locality 

48. Reported from Timms Point silt and Palos Verdes sand. 

15. Chlamys anapleus Woodring, n. sp. Type, incomplete left valve. Length 23.2 mm., height 19.5 mm., diameter 4 mm. 

U. S. Nat. Mus. 498642. Locality 30. Found also in Lomita marl. Not known to be living. 

16,17. Cerastoderma nuttallii (Conrad). Left valve. Length 56.5 mm., height 50.5 mm., diameter 17 mm. U. S. Nat Mus. 

498643. Locality 30. Found also in Lomita marl, Timms Point silt, and Palos Verdes sand. 

18, 19. Trachycardium quadragenariutn (Conrad). Small right valve. Length 62 mm., height 57 mm., diameter 21 mm. 

U.S. Nat. Mus. 498644. Locality 30. Found also in Lomita marl, Timms Point silt, deposits on third and second 

terraces, and Palos Verdes sand. 

134


PLEISTOCENE MOLLUSKS FROM SAN I'EDRO SAND. 

X 2


23 24 

PLEISTOCENE MOLLUSKS FROM MARINE DEPOSITS ON FOURTH AND SECOND TERRACES AND FROM 1'ALOS VERDES SAND.

PLATE 35 


FIGURE 1. Acanthina lugubris (Sowerby). Length 34 mm., width 23.5 mm. U. S. Nat. Mus. 498645. Locality 82, fourth terrace. 

Found also in deposits on second terrace. 

2. Pecten vogdesi Arnold. Worn broken right valve. Length 59.5 mm., height 56.5 mm., diameter 20 mm. U. S. Nat. 

Nat. Mus. 498646. Locality 105, second terrace. .Reported from Palos Verdes sand. 

3, 4. Pecten vogdesi Arnold. Broken left valve. Length (incomplete) 53.5 mm., height 55.5 mm. diameter 6.5 mm. U. S. 

Nat. Mus. 498647. Locality 105, second terrace. 

5, 6. Trigoniocardia biangulata (Sowerby). Right valve of medium size. Length 26.4 mm., height 24.3 mm., diameter 9.5 

mm. U. S. Nat. Mus. 498648. Locality 105, second terrace. 

7. Calliostoma eximium (Reeve). Length 7.6 mm., width 8 mm. U. S. Nat. Mus. 498649. Locality 121, Palos Verdes sand. 

8. Rissoina pleistocena Bartsch. Length 4 mm., width 1.8 mm. U. S. Nat. Mus. 498650. Locality 140, Palos Verdes sand. 

Found also in deposits on second terrace. Not known to be living. 

9. Turritella cooperi Carpenter. Length (incomplete) 41.7 mm., width 10.5 mm. U. S. Nat. Mus. 498651. Locality 112, 

Palos Verdes sand. Found also in Lomita marl, .Timms Point silt, and San Pedro sand. 

'10, 11. "Nassa" fossata coilotera Woodring, n. var. Type. Length (almost complete) 48 mm., width 25 mm. U. S. Nat. 

Mus. 498652. Locality 108, Palos Verdes sand. Not known to be living. 

12,13. " Nassa" delosi Woodring, n. sp. Type. Length (incomplete) 34mm., width 19mm. U. S. Nat. Mus. 498653. Locality 

113, Palos Verdes sand. Not known to be living. 

14, 15. "Nassa" delosi Woodring, n. sp. Length (almost complete) 30.7 mm., width 17.7 mm. U. S. Nat. Mus. 498654. Lo 

cality 120, Palos Verdes sand. 

16, 17. "Nassa" cerritensis Arnold. Length (almost complete) 25.6 mm., width 13.6 mm. U. S. Nat. Mus. 498655. Locality 

120, Palos Verdes sand. 

18, 19. "Nassa" cerritensis Arnold. Length (almost complete) 21.5 mm., width 12 mm. U. S. Nat. Mus. 498656. Locality 

120, Palos Verdes sand. 

20. Forreria belcheri (Hinds). Length (incomplete) 103.5 mm., width (not including spines) about 63 mm. U. S. Nat. 

Mus. 4,98657. Locality .123, Palos Verdes sand. 

2.1. " Cancellaria" tritonidea Gabb. Length (almost complete) 49 mm., width (not including nodes) about 30 mm. U. S. 

Nat. Mus. 498658. Locality 120, Palos Verdes sand. Found also in San Pedro sand and in deposits on third terrace 

(identification doubtful). Not known to be living. 

22. Olivella pedroana (Conrad). Neotype. Length 12 mm., width 5.7 mm. U. S. Nat. Mus. 498659. Locality 113, Palos 

Verdes sand. Found also in San Pedro sand. 

23, 24. Anadara perlabiata (Grant and Gale). Small left valve. Length 12.9 mm., height 11.7 mm., diameter 5.3 mm. U. S. 

Nat. Mus. 498660. Locality 124, Palos Verdes sand. 

135 

502787 45 1.1.

PLATE 36 

[Species illustrated are still living unless otherwise specified] 

FIGURES 1-4. Crassinella branneri (Arnold). U. S. Nat. Mus. 498661. Locality 120. Found also in deposits on fourth terrace. 

1. Right valve. Length 9.8 mm., height 8.3 mm., diameter 2 mm. 


3. Right valve. Length 8.8 mm., height 7.7 mm., diameter 2.6 mm. 

4. Left valve. Length 8.8 mm., height 8.2 mm., diameter 2 mm. 

5, 6. Crassinella branneri (Arnold). U. S. Nat. Mus. 498662. Locality 124. 


6. Left valve. Length 8.6 mm., height 7.2 mm., diameter 1.8 mm. 

7, 8. Crassinella nuculiformis (Berry.) Right valve. Length 4.5 mm., height 4mm., diameter 1.1 mm. U. S. Nat. Mus. 

498663. Locality 124. Found also in deposits on.second terrace. 

9, 10. Crassinella nuculiformis (Berry.) Left valve. Length 5 mm., height 4.6 mm., diameter 1.1 mm. U. S. Nat. Mus. 

498664. Locality 124. 

11-14. Diplodonta sericata (Reeve). U. S. Nat. Mus. 498665. Locality 135. Found also in deposits on second terrace. 

11, 12. Right valve. Length 13.7 mm., height 13 mm., diameter 3 mm. 

13, 14. Left valve. Length 10.8 mm., height 10.3 mm., diameter 2.5 mm. 

15, 16. Dosinia ponderosa (Gray). Broken right valve. Length (incomplete) 113 mm., height (incomplete) 97 mm., diameter 

30 mm. U. S. Nat. Mus. 498666. Locality 135. 

136

PLATE 37 

[Species illustrated still living unless otherwise specified] 

FIGURES 1, 2. Chione gnidia (Broderip and Sowerby). Left valve. Length (almost complete) 55mm., height (almost complete) 

47 mm., diameter 17 mm. U. S. Nat. Mus. 498667. Locality 135. 

3, 4. "Chione" picta Dall. Left valve. Length 9.4 mm., height 7 mm., diameter 2.6 mm. U. S. Nat. Mus. 498670. 

Locality 121. Reported from deposits on second terrace. 

5, 6. Trachy car dium procerum (Sowerby). Right valve. Length 75 mm., height 79 mm., diameter 33 mm. U. S. Nat. 

Mus. 498668. Locality 121. Reported from San Pedro sand. 

7, 8. Tr achy car dium procerum (Sowerby). Left valve. Length 55 mm., height 55 mm., diameter 23 mm. U. S. Nat. 


137

A Page 

Acanthina.____...................__.. ........._.... .... . 76 

lugubrls.............................................................. 76, pi. 35 

splrata. .. ....... ... .... ................ 76 

punctulata........................................................... 76 

Aclla castronsls.___...................... ..........__................ 78 

Acknowledgments..-.-....--.-.--...-..-.-.-.--.---..-----....-.--.--.-.----- 3 

Acmftoa................................................................__. 61 

asml...........I.........-..-...........-------....-..-....-..........--.. 61 

funiculata........................._................................. 61, pi. 34 

inscssa______........................................................ 61 

loplsina.. 

llmatula. 

persona., 

scabra. 

of. A. ocbracoa. 

Acmaoldao........ 

Actcoclna tumicla.. 

Actoon. 

...................................................... 61 

.... 61 

..................................................... 61 

..................................................... 61 

..................................................... 61 

..................................................... 61 

..................................................... 78 

..................................................... 78 

brovlculus...................................:.. - - - -........ 78, pi. 30 

schonckl. ... ...... . ........ ............__.........._ 78 

nculoatn, Oropldula_...................... ............................... 71 

aonta. Dlala......_____.........____._........._................. 67 

acutollrata, Alvanla......._-----_.__...............__..__......... »65 

aeuticostata, Liotia.-_...............__.................................. 63 

Puplllarlaoptabills. ..--.-. -.- -.-------....._-...-..-...-......:.- . 62 

Ad mote........ _........................................................ _ 77 

couthouyl................................................................ 77 

graclllor.._-----_................................................. ..'.. ' 77 

rhyssa._.__...... . ._......................................._ 77 

woodworthi.............................................................. 77 

adunca, Oropldula_.___._.....................................__... 70 

Aoqulpecton.............................................................. 26, 27, 80 

andorsoni....__......____..._................................ 26, pi. 28 

circularls.............._................................................ 80 

aoquisulcatus. .. -.._......._-..__".._..___.______........... 80 

cf. A. sanctl-ludovlcl......_......................._.............. 27, pi. 28 

aoqulsculpta, Klssolna._....................................._........_ 66 

aoqufsulcatus, Aoquipecten clreularis.......---.---..........-...-.......-.... 80 

Aesopus.........._......_.........................................._... 77 

cnrysalloldos__........................................................ 77 

Idao...................................................................... 77 

aothlops, Macron...____.........................................___.. 75 

Agriculture in tho area.....__......................................_.... 8-9,11 

Agua Nogra Canyon area.. .......................................:. ...... 22-23 

Alabina...................................................................... 67,68 

dlogonsls. 

tonulsculpta.. _ .... 

Alabinlclno__............ 

alaskonsls, Propoamusslum. 

Aloios squamigorus......... 

Algao. 

Alluvium_................................................................. 

almo, Alvanla........_ ............ ... ... . __... 

alta, Novorita roclusiana_.................................................... 

Altamira Canyon area........................................ 21-22, pis. 4, 27, 

Altamlra shale member.......................... 16-33, 39-40, pis. 3, 4, 6-9,10, 

Alvanla__.................................................................. 

acutollrata........................................................_..... 

rosana......._.... 1................................................. 

almo._............ .......... . . ._ __.. __ 

fOSSillS....__............................................................. 

montoroyonsls.......................................................__. 

pod roana................................................................. 

purpuroa. .............................................^...............^.. 

rosana.................... ... ... .......................................... 

Amorlcardla.............._. .... . ........................ .................... 

Amlantis callosa.................... ................... ......................... 

Ainnlcola longlnqna................ . ...... .... .... .........-...._.. 

ATTinlcoliclao_....................... ..... ...-...........................'..... 

Amphlssa..._................................................................ 

col u in b iiuin_............................................................ 

rotlculata................................................................. 

undata................................................................... 

von tr Icosa................................................................ 

vorsicolor................................................................. 

Amphithalamus Inclusus.......'......-.........-............................. 

lacunatus_.............................................................. 

ampla, Panomya......_................................................... 

Anachis. 

nrnoldI................................................................... 

minima............................................ ._-._____......_.__..._. 

ponclllata.......................................... .......... ......... ... 

(Costoanachls) sp_.__......................... ... .. ............. 27, 

Anadara perlabiata.__................................................... 79, 

unaplous, Clilamys_....................................................... 8li 

andorsoni, Aociuipocten................................ .................. 26, 

anollum, Vormotus........................................................... 

angulata, Noptuncahumerosa................................................ 

annulata, Lucinoraa.......................................................... 

annulatum, Calliostoma...................................................... 

Anomia poruviana_ ......-.-.._.._.._.___ ..___ .._._ .____ _ _ 

Anomlidao..._.._._.......____.^.................................. 

antomunda, Corithlopsis__................................................. 

antlllarum, Trigoniocanjia aff.______................................... 27, 

antlquatus, Hipponlx.._......___..._.__..................._...... 

Area lablata..................................._............................ 

sisquoconsls__....... -.-._ _____.- -._ _. .. ___..... 

Arclclao_.----... -.. .. ...................__ __.. _.. 

armillatum, Bittium................................._........_.... 67, 68, 

592787 4.5- 

-12 

INDEX 

108 

66 

71,72 

B, C 

J3.28 

65-66 

65 

65 

66 

66 

66 

65 

66 

65 

" 85 

84 

66 

66-67 

77 

77 

77 

' 77 

77 

77 

65 

65 

'85 

77 

77 

77 

77 

pi. 28 

pi. 35 

pi. 34 

pi. 28 

69 

75 

83 

62 

79 

79 

69 

pi. 28 

70 

79 

79 

79 

pi. 34 

Page 

amoldi, Anachis......_.._._._.................. .-.--.-................i.-.-- / 77 

Barbarofusus_..................................'.:..........:..... r .: 73, pi. 34 

cf-................................................................ 73, pi. 32 

Cerithiopsis....-..-.....-......----------..-...-----.-.-.........-......... 69 

asmi, Acmaea........__-...-......-.-..._....-..-....-....-.._.._. 61 

aspera, Tritonalia lurida....-..-....--.--...-.......-..-............-__... 75 

asperum, Bittium..___...__...__... .__... .... .._.....__.. 67-68 

Atrimitra..............__...__................_...._....._........... 73 

attenuatum, Bittium______....._.............__.._.___.___ 67-68 

aurantia, Tritonalia circumtexta.. ...--..........--..-..-._............._ 75 

aurantiaca, Lacuna unifasciata__........................................... 64 

aureatincta, Tegula_.........__._...................................... 62 

avalonensis, Borcotrophon .. .................................. p _. 76 

B 

bacula, Homalopoma..__..._............................................ 64 

baetica, Olivella........................................'....-.................. 77 

barbarensis, Barbarofusus........__...................._....._...... 73,pi.34' 

Cyclocardia.--....-._---_-._..__._......-.._....-._................... 83,pi.31 

Glycymeris____ ..._.-._- _. ._..---. -....__. __..__._ 79 

Ocinebra.._____...._........_..__......._................... 76 

Tritonalia................................................................ 75 

Barbarofusus-__.............._.... ......... .........__..... 73 

- arnoldi.-. -_...--.---_-.-------------_----.---------.-----..---.. 73,pi.34 

barbarensis.......-...---.-...--.-.------.-................. ............ 73,pi.34 

cf. B. arnoldi-.....-...-------------------..--..-----.----.------..--.. 73,pi.32 

Barleeia..._____............-....... ........ .......___.. -., 66 

californica.. 

dalli. .... 

haliotiphila. 

oldroydi.... 

Barnacles. 

..................... .................................. 66 

............. .. . . . .- 67 

............. ... .-.... - ...-. ....... 66 

......-.......---.-- -...... --..-.-..........-... 66 

....................................................... 85 

Basaltic rocks....................................................... 108-109, pi. 6, C 

Bela ....... -1 77 

belcheri, Forreria.'____._.._.._.......__........ ._......... 76,pi.35 

berlngianus, Chlamys islandicus_........................................... 81 

Panomya.______._.__.............._.,.._._............. 85,pi.33 

berryi, Cerithiopsis.____.__...... ......... . ._.___... 68 

biangulata, Trigoniocardia............ . _... . _____ 85, pl/35 

Bibliography.................. . .. ,. __________._ 3-8 

bifurcatus, Septifer....:___........... .. _. ......._......... . 80 

biplicata, Olivella...................-............-.- -. -..... ... 77 

Birds...-.........-.....---.-..-----.--.--------..-----.---------.---.-......- 86 

bisecta, Thyasira._____.............. .___. ...__._._... 83 

biserialis, Nucella....__ ........ .................................. 76 

bistriatus, Pseudamussium. ......... . . .... ..... 81 

Bittium........................--.....................-------.-----...-..... 67-68 

armillatum..-__...--.------..................................... 67, 68, pi. 34 

asperum......__........................................................ 6.7-68 

lomaense.------------------------------------------------------------ 68 

attenuatum. __...^........................... .. ............._.. 67-68 

catalinense.___....................................^.................. 67-68 

cerithidioide........................................................... 

eschrichtii. 

montereyensis. 

giganteum:........ 

interfossa. 

................................................. 67 

................................................. 67 

-, . :-.- 67 

.__.... .-. .-......-- .--....-....... -... 67 

ornatissimum...__. ..._ - . _ . . . .... 68 

purpureum....___.--...-..-...-..-.--.....-...--..-.......--.._..... 68 

quadrifllatum..-.__.........-........................-............'. ._ '67 

rugatum.......................................................... 67, 68, pi. 29 

lanun--. - .- .67, 68, pi. 29 

serra_........._......__.. .-.._ ._.-. . ._.-_-.-. .._. 67 

subplanatum...._..-....-........-----......-....--....-......'.---..-.. 67 

(Elachista) californicum._.......... ................._............ 68 

Bluff Cove area...........:.........-----..----......--.... 18-19,20-21, lll.pl 6, B 

Boreotrophon. 

avalonensis.......... 

calliceratus.__..... 

orpheus.____.... 

pedroanus........... 

praecursor........... 

aff. B. multicostatus. 

aff. B, stuarti_..__- r - 

cf. B. paciflcus....... 

cf. B. raymondi._. 

Borsonclla........._... 

Botulina. 

Brachiopods___............._..............._. ....... . 60 

branneri, Crassinella...._. . ... . _. . -. , 82, pi. 36 

breviculus, Acteon.._......_....._.___.___ ................ 78, pi. 30 

brevis, Turcica caflea.._................ .__........................... 62 

brunnea, Tegula_....................^..................----....,.----.-....- 61 

Bryozoa................................... ......,............._........... 60 

burragei, Rissoina.. ...........-...-....-.........-...--.----......-.--------- 66 

Bursa californica. ................................................... 72, pi. 29 

Bursidae.-...._._......-.....-.-- . . . . . ----- 72 

Cabrillo fault..... ... P 

Caecidae........_.................. ....................... . 

Caecum...__..__._........... . ....... ....... 69 

californicum__...._.._..... ..... .............. . .... 69 

grippi...._ .. 69 

magnum...._.. ................... ............ ..... 69 

caffea, Turcica.......__...-.-..-................-.....------..---..---- - 62, pi. 32 

calcarea, Macoma_......----....-.------- -.... ...i.. 84, pi. 33 

-.-- 139 

76 

76 

76 

76 

.76 

76 

76 

76 

76 

76 

77 

80

Page 

Calicantharus fortls.................................................... 74-75, pi. 29 

californiana, "Nassa".....................................................___ 74 

californianus, Mytllus.................................................___. 79 

californica, Barleeia...............................1....__.............___ 66 

Bursa..,..____..................................................... 72, pi. 29 

Cerithidea..-....----..-.-.-----.--.-......-.-.-..-.----.-..-..-......... 68 

Cyclocardia. ..................................................._ 82 

Epilucina.___._____....................._."..'..... .............. 83 

Hyalina................................... .............................. 77 

Trivia.................................................................... 72 

Truncatella......________......._...._.................^........ 66 

Valvatahumeralis..-.._-...--....____................__...___ 65 

californicum, Bittium (Elachista)........__......._......__.........__ 68 

Caecum._........___................................................ 69 

Elassum.._________..........._......................___ 68, pi. 29 

californicus, Conus..... --.-..,..---.-... ------.--.-------...-.-..--.-..... 78 

calliceratus, Boreotrophon............................................._._ 76 

Calliostoma._______................._.........._...........____ 62 

annulatum.. .. ---.........-....----.--.......-..-..........-...__ 62 

canaliculatum. _.._........__....................._______ 62 

costatum..... .................v..................._.___....__ 62 

dccarinatum_..-.-...--...---.......--.......--....---............_.. 62 

eximium.__.__................................................... 62, pi. 35 

grantianum_------....---------.--.---.----..----------.--....-...--.... 62 

ligatum..... ..............................._........._......__ 62 

supragranosum. ..................................................__ 62 

virgineum..... -.-...---....--.--.---........--.----.--.....-..--.... 62 

callosa, Amiantis-.. ....f .......... .-....-..-.--.-..-........-....__ 84 

Neverita reclusiapa. ......... ................................ 72 

Calyptogena_. ...--.-.-...--...-.-..----...-.--.------. -....--.--..... 83 

gibbera................................................................... 83 

paciflca._______.........-..--..-.._...................__.___ 83 

Calyptraea._... ......-...........----.'-.-...-.--.-..-.......-.-.-..... 71 

fastigiata__ .................................. .................... 71 

mamillaris__ .....................^.................................... 71 

Calyptraeidae.__ ___..........................................___ 71 

canaliculatum, Calliostoma....-..-----..-.---......--.....-.........-...-__ 62 

Cancellaria___.___.:........--...-.._.........._...........__.__ 76 

cassidiformis_-.--.....--------..-.--..-........-.............._.__ 76 

tritonidea........-.....-..-.;--...... ..-........................._ 76, pi. 35 

cf. C. condoni. ....--...-. ...............__.__...____ 27, pi. 28 

Cancellariidae..-.-------------------.--...-.......:....................._ 76-77 

Cantharus elegans........................................................ _. 75 

insignis...... ...................................................._ 75 

Capistrano Beach..--.-.....-.-..-......-.-...-...- ...-................._ 105 

cardara, Nucula afl......----................................................. 78 

Cardiidae.....-..-----------------------------.I----.-.------._._.-------._.-_ 84-85 

Cardita......-. .--.--.......---.......---.......-......-....-.-..-....... 82 

carpenterl..___._.................................................... 82 

minuscula..--. -.....-.-...-..--.. .-.-......---.-..................... 82 

monilicosta.---------------------------------------------.--..-.--.---...- 82 

occidentalis..---------.----------.--------------.-.-..-....-.---------.-.- 82 

subquadrata-. ....................................................__ 82 

ventricosa'......--.-----.-.-.-------.-.---.-......-..............--...._ 82 

Cardltidae....... -. -- - ---- ..... .-.-.-..._.-._.- 82-83 

carinata, Lacuna--..---.-----.-.----.--.--.---.-....-.---.--..-.....-.-_:.. 65 

Mitrella.................................................................. 77 

carlottensis, Macoma...__............................................___ 84 

carpenter!, Cardita... __._.....-..._...._.._.._...____ __....__._______ 82 

Homalopoma..._................................................ 63-64, pi. 29 

caryophylla, Puncturella............................................_.__ 61 

cassidiformis, Cancellaria..................................................... 76 

castrensis, Acila....- __.................._.......................__ 78 

catalinense, Bittium_____...............................___...:..._.. 67-68 

cataractes-Pecten ...-.....--. .-.-.-...--..--...-..--.-....................... 80 

caurinus, Patinopecten__..--............................'........... 81,pis.32,33 

centifllosum, Pratulum._................_........................._ 85, pi. 33 

Cerastodenna nuttallii___._.-.--.-.---.-.-........................... 84, pi. 34 

Cerithidea californica.__...................................... . ....... 68 

eerithidioide, Bittium....................................................__ 68 

Cerithiidae....___._....................................... ......... . . 67-68 

Cerithiopsis....._._...............................................___ 68-69 

antemunda..._...................................................__ 69 

arnoldi..._............................................................. 69 

fossilis_-------------------------...--_.-............_______-...-._ 69 

berryl..._.._--..__._._.....__..._...._. .._....._......_..__.............. 68 

cosmia.-__._......................................................._ 68-69 

diegensis. . .......................................................... 69 

fatua _ ......................................................_ 68 

gloriosa.__.___............................. .............I:.....__ 69 

necropolitana.------..----.-.-.-.-..-.-....-.....................--....--. 69 

pedroana...--- . ................................................. 68 

fatua-___--___..----.-.-..-...........-....... ...... . 69 

willetti.__...-.-.-...._........-.__..........._.___.____.____............. 69 

williamsoni...-..--.....__............................................. 68 

cerritensis, Leptopecten latiauratus........................................... 81 

"Nassa"..___...____--.-...-.-.-.--....-.....-.-...............74, pi. 35 

Ocinebra lurida._....___......................................._ 75 

Trophon.....___._____...........-..........................:..... 76 

cerrosensis, Ostrea megodon__.-.--...-..-..........-.-.-..-.....-........ 81, pi. 30 

Certhiopsidae......_______........................:...........^........ 68-69 

charybdis, Crepipatella_____..................................... 71, pis. 29,32 

Chionegnidia.... .______............................... ... ...... 84,pi.37 

picta......._....,.._________._.____!._________...____._.._.__.__.___._ 84, pi.37 

(Lirophora) aft. C. mariae..._........................................ 27,pi.28 

Chitons...._..._........._............................................. 61 

Chlamys..-.-..-.-...--.--.----.-.-.-..-.-.-,._............... . ........ 80 

anapleus....._...................................................... 81, pi. 34 

etchegoinl.,___....................................................__ 81 

hastatus_.__......................................................... 80 

hericius__.__.-I-.-.-.-.-.---.----.--.-.-......--..................... 80 

islandicus____...................................................__ 80 

beringianus_......................................... ... .. 81 

hindsii. -----------_-_..---.___._...._._._.._._____.___ ...... 80 

jordani____.................................................. 80, pi. 32 

navarchus.._........................................................... 80 

opuntia..__..__...................................... ... ....... .. 80 

parmeleei.....____..............................__.............__ 81 

chrysalloides, Aesoptls........................................................ 77 

Chrysodomus................................................. . ...... 75 

diegoensis....-----__... ............................... . ........ . 75 

pabloensis___............i.......................................... . 76 

PJdariQacidarls.........................,.,..,..,.,,,.....................;., .52 

INDEX 

cidaris, C idarina_......^................................................... 

circularis, Aequipecten....................................................... 

circumtexta, Tritonalia__.......................................... ..... 

cistula, Lasaea_.-..._.................................................... 

citrica, Tritonalia circumtexta................................................ 

clausa, Cryptonatica.._...._.............................................. 

Clavatulacf. C. labiata................................................ 27, 28, 

Climate of the area.__._._........................................._.. 

Clinocardium.-.-.._.___.................................. ........... 

coalingaensis, Pecten....... __....___...................i................... 

coilotera, "Nassa" fossata_.............................................. 73, 

collinus, Qlossus (Pectunculus)_...............................^........... 

columbella, Erato ------- _ --...--.....-..................-..-..--....-...... 

solidula_------------_..-----_--_---_------.-.-.------.-.....--.--.._.._ 

praecursor____...__......................^..................... 

Columbellidae................................................................ 

columbiana, Amphissa....................................................... 

compacta, Lacuna.--.......-.--------.....------.-.-..---.-..........-........ 

compactus, Pecten__.____.__-.--.-.-.------.---_--__-_.--_____........_.... 

Compsomyax.----------..---------.--------.----.-----.-.-..--.-.---......-.. 

compca, Tricolia..----.._.._._-----------_------------.------.__._-----.._.-.. 

Conchocele.----------------.------.--------------------.---.-----------.-.-.condoni, 

Cancellaria cf. _..--_---.------------------.....--..-..-------.. 27, 

Conidae.--------..-.-----.-..------.----------....---------.-----.--.-.-.-.-.. 

Conus.. --.-.---- --.----.---.--.--------..-.---...----....--.-.-.....-.californicus--.--.--.-----_.--......---.-.----..-..-.....-..........._. 

fossilis.-..---.-----.--.----..----- --------...---.-----.----.-.-.....-. 

Page 

62 

80 

75 

84 

75 

71 

pi. 28 

8-9 

84 

80 

pi. 36 

79 

72 

77 

77 

77 

77 

64 

80 

84 

64 

83 

pi. 28 

78 

78 

78 

78 

owenianus..---------.-------------------------------------..--.-.-_ 28, pi. 28 

cooper!, "Nassa" mendica.__ ....--....-...-.........-.-...-...-.-.. 74, pi. 34 

Progabbia.._.______ _........ ..... ,................... 77 

Puncturella.-.-._____.. ..........................._......... 61, pi. 29 

Turritella....---..--....-.--..-..--..-..--..-......--.-........ 69-70, pis. 34,35 

Corals...................._.-.._.._........_..............._...... 60 

coronadoensis, Cyclostremella-..__...._............................_.. 63 

Rissoina..__..___.__________.....____....r........ .. 66, pi. 29 

Correlation of formations, Miocene series................._._....... 

40 

'Pleistocene series._____ ____.._............_........ 96-106 

Pliocene series..._._._................^......^.............. 42 

cortezlana, Glycympris...___.....--.---.---............................... 79 

coryphaena, Tritonalia_____..__.._.............^.^ ...............76, pi. 30 

cosmia, Ceritblopsis._____._____......--.-....__._.............. 68-69 

Rissoina.----._._.___....._._._.........._.................. 68 

costatum, Calliostoma.....__.._.........^.............................^^ 63 

couthouyl, Admete...-.........-......----..-......-....-----...;.----.....-. 77 

cracherodii, Haliotfe____.__........___..-.-...-. ...... ......... 61 

cranioides, Hipponix antlquatus...-....-.....-..------.-.-..--............... 70 

Crassatellidae_...-----.._...-..........--....--...-..--.--......-.-..---. 81-82 

Crassatelliteslomitensis....--__..__...-......-...------_............... 82 

Crassinella...----__.._....--....---.-..--..-......---........-----.. . 82 

brannerl......_...-..-...----_....----.....---.-- ...............82, pi. 36 

nuculiformis.._____________. . .. .. ---- 82, pi. 36 

varlans..._.._____.......... .... . ........ ........... 82 

cf. C. mexlcana....__.................................._......... 27, pi. 28 

crawfordiana, Crawfordma....-----..- ....................... ......... 77 

Crawfordina crawfordiana._. .. _--.-_.-..-...-.-.- .... ----- 77 

crebrlcinctum, Micronellum.............-.---.-...................-.-.-....-- 69 

Crepidula..________..........__...--....__._.:.-.._........,--.-...- 70-71 

aculeata.... .....................................^,.^...^. ........... 71 

adunca.... _____...___...______._..._.__.. _-..__..._............ 70 

excavata_._.._---.--..-.-.--.-..--.-.......--------.-. ........... 70-71 

grandis.._________........___....... ...................... 70 

nummaria.__.-..-....-.....--.._.--.---. -...__.............. 71 

onyx. 

70 

orbiculata.---------------------_.....---..----.... -.-.-.........-..-.-- 71 

princeps___.........................^.............................. 70, pi. 32 

rugosa..__.---------_--.-._,---.---_---.----_-.-----_----.---------------. 71 

saugusensis.__--..............-.-...--.-.-......--------....------- .- 71 

Crepldulidae..--.----------.---- ----.------------------------------- ------ 70-71 

Crepipatella____-....___......... .......... .... . ..-- 71 

charybdis.-.-.:-.-..-..-....................-..-----------.......... 71, pis. 29,32 

llngulata__-..........--..--.-......-----...-..-..--.-,..------.--.----- 71 

Cruclbulumsplnosum.._.... ........................... ........... 71 

Crustaceans...--------_.--....-..-...........------.--. ........... 85 

Cryptonatica.--.-..-----.--......--..-.......--..-------------.--------------- 71 

clausa...._______.................. .... ................. 71 

russa. 

71 

cucullata, Puncturella.. ___ ...--..-.....-..-..-- ........ ............ 61 

Cuminpia lamellosa _ . ___ ..... __ ... .............-..---.----. .. 84 

Cunearca. .. _ . _ .---..---...--..--.---...-.-. .......................... 79 

curta, Eupleuramurlciformis...- .......... ..... ........................ 76 

Paludestrina ..... _ ....-.......-.....-.-.....-..-........----..-.--- 66-67 

Thracia _ ___ ...... _ ........................ ............. ...... 85 

Cyclocardia...-- ...... _ .................... .................... ..... 82-83 

barbarensis .... ..... ".....-...-.......--......-...-.. 83, pi. 31 

californica- ___ . __ ..-. __ .... __ .. __ -- -- ---- - 82 

nodulosa ..----.....-....-...-.-...--. .. ...---..--.-- .. .. 83 

stearnsil __ .... ____ ---. ............. . . 

83 

ventricosa.---.--- _ .- __ ...... ......-..-..----.-... -- 82-83 

afl. C. occidentalis-.......- -...-..- -..-...- ---- -- 82-83, pis. 31,33 

Cyclostremella----. _____ .... __ ... ----- - 

63 

coronadoensis . ___ ........ ..... . ........ ...... 63 

Cymatiidae. . . . . . ..... .. . . .... ...... 

72 

Cypraeaspadicea --....-.. _ ----- _ .---..-.........- .....--- .... 72 

Cypraeidae.. ----------------- .......--.----.-..-.--.-..-.---.------------ 72 

Cypraeolina pyriformis . .. ---- - 77 

Cyrillamunita.---- . ___ ... --- ..-.....-----.-..---.-.--... 78 

D 

dalli, Barleeia... . - 67 

Rissoina ---------.... _ _ ... ---------- ---..-.... 66 

Dallocardia _ .. _ . -- ----- ...- -... ------------ 85 

Deadman Island .. __ .. _ .... . ... ---- 45,56 

decarinatum, Calliostoma-.... --...-----.-...- ......... ^......... ...... ... 62 

Delectopecten. -.--.-.-.- _ ....---......----..-..-.----..--.--.-.-------.---- 81 

delosi, Leptopecten latiauratus... ...... ... ...- ...------.. ....... . 81 

"Nassa" .-------".-.- __ - . - ...... 74, pi. 35 

Puncturella __ . ____ --.---....-.---..-..-.----- - ------------ 61, pi. 29 

Diala. 

67 

acuta.__. 

67 

marmorea. 

67 

varja...... 

67

Page 

Diatomlto...... -...... . . .-- - 119-120 

(llogonsls, Alabina.. . ........... .............. ....... ... 67 

Ccrithlopsls........................-...-.---.-.--------- ----.......-..-. 69 

Pocton...........--........-..........----.-.-------------------.--.--.._ 80 

Stoamsll. .... .... . . -----..-_-... 80 

dlogoonsls, Chrysodomus...........__................... .......___ 75 

Dlplodontasericata........................-.-.--------.--------------. 83-84, pi. 36 

dlsjuncta, Thyaslra....................................................... 83, pi. 33 

dlvarlcata, Lacuna......__.._...._................... ......___ 65 

Divaricolla of. D. oburnoa.................... ............................ 27, pi. 28 

Dooomphala . . ... . ----- ... .. 63 

Dosinia pondorosa.._._......_......... ......................... 84, pi. 36 

afT. D. pondorosa............................-.-....--.------.-.....-. 27, pi. 28 

clumbloanus, Phos............ ............ ................ 27, pi. 28 

Dunesand......... ....- . .-. - -. - - 107-108,117 

E 

eburnoa, Divarlcolla cf..........-............--------.-- .---.-.-.......-- 27, pi. 28 

Echlnolds..---.-..-----.--..----------------------------.-------------------- 60 

El Scgundo ollfleld, location of.___....... . ... ...._..._ 8 

Elachlsta................._................................................. 68 

Elassum callfornlcum........_.............................. ._.... 68, pi. 29 

olatuin, Trachycardlum.-............--..----.--.-...-..---------..-.-------- 8fl 

oldrtdgoi,Jaton... .... .-. .......... .......... 75 

ologans, Cantharus.. . ..-..._.. . 75 

omarginata, Nucolla._..____._..._.._.........-.--.-.______.__ ....... 76 

Environment suggested by fossils...--.-----.-.-.-.-------------. 39-40,42,86-96,102 

Eplluclnacallfornlca._______.......................... ___..__ 83 

Epitonlldao.....- - ----- -- --- - 72-73 

Erato...... . .. . -- -- - 72 

columbolla_ ...................................................... 72 

vltolllna. ...................-... -..- - .. . 72, pi. 30 

oschrlclitll, Blttlum....-............-....-..---.....-------------.....-......- 67 

oshnaurl, Vltrlnolla...............................-.--------..-.............. 63 

otchogoinl, Chlamys.. ................ ................. -..--. .. 81 

Eucrassatollafluctuata.......... ..... . .... ..._._ 81-82, pi. 31 

Eullthldium................-..-.-.-.-...----.-.-.--------------------- 64 

Euploura. 

grlppl.......-.. 

niurlciformfs curta. 

ploistocononsis. 

Euvola. 

..........................^................................... 76 

....... .-.-.......-....--.-..--.... ... .. 76 

......... -..---....--.......-..-.-.-.------ 76 

..............-...--.-.-----..-------.-.--- . 76 

................................................. 80 

oxcavata. Oropidula.. . .... ..... ..-.--. ................. 70-71 

oxlgua, Nucula.... . ..................... ....... .............. 78 

Exllloldoaroctlrostrls...__...... . ...... ................. 74,pi. 32 

oximium. Oalliostoma..... . ........ ... ................... 62,pi. 35 

Exploration In the area ......... ._.__.__.._, 3 

Fortulum..__... .... . . .......................... .. 69 

homphllll..... --.--.-. -.-.------------------------,------...--.--- 69 

occidoutalo.._. _...--.-.....-..-.-----.-------...-------------.--.- 69 

orctittl.......... _.........-.............-.-.-----------..-.......... 69 

fastlglata, Calyptraoa. ........ .......... .................. 71 

fatua, Gorithiopsls. _...... .... .. ...... .__.......... 68 

Corlthlopsfs podroana..................................... . . ... 69 

fonostrata, Isollca... . ... ................. ............ 65,pi. 34 

Llotla................... .. .. -- - -. ... .. 63 

fonostratum Honialopomapauclcostatum..................................... 64 

fostlvus, Jaton. ... ........................... ... 75 

Field work..__________..... ....'............................._ 2-3 

jTissurolla volcano... ___ ................... .. ... ....... 61 

Flssurollldao..... .- . ..-----.--.-------.--.--.-- --. --.. 61 

fluctuata, Eucrassatolla.__.....__......... ..................... 81-82,pi. 31 

Foraminlfora......................................... 19,25-26,32-33,35-37,39,42,60 

fordll, Vontrlcola ....................................................... 84, pi. 31 

Forrorlabolchorl...................-..-..-----.----------.-----....-..-... 76,pi. 35 

fortls, Calicantharus.__...._......._......................__ 74-75,pi. 29 

Fossarldao......... _______...................................__ 65 

fossata, "Nassa"...... ..... .....................................__ 73 

Fossil localities..-........ ..........-................... .............. 120425 

fossills, Alvanla.___.._____................................__....__ 66 

Oorithlopsls arnoldl_._... ...... ......................___.._ 69 

Conus callfornlcus. . .............................. 78 

Trlphora..._._____._____......_...__.__._............ 69 

Fossils, environment suggested by............................... 39-40,42,86-96,102 

Miocene.................................... 16,19, 25-28,32-33,35-37,39^0, pi. 28 

Pleistocene................................................... 60-96,pis. 29-37 

Pleistocene to Recent____.___........... ... ___._.. 107 

Pliocene.................................................................. 42 

See also names of fossils. 

fovoolata, Tritonalla...._____....... ......... ......._._._ 75 

fragills, Pocton (Cblamys) latiauratus................_.....__.__.__ 81 

fulgcns, Hallotis........................................ ................... 61 

fultonl, Mltra.......-.............-.--..-.--................................. 73 

funobralls, Tegula.._____........_...................._.._._.... 61 

funlculata, Acmaca____.........___............_............^..... 61, pi.34 

Knofastiacf........................................................... 27,pi.28 

fusconotata, Trltonalia.........................................__........_ 75 

Fusinidao...........___ ._.__..........._....._............ 1_._ 73 

Fuslnus lutoopictus.._____.............................................. 73 

Fusltrlton orogonensls..___....____.........._............_.... 72,pi.32 

Fusus (Bucclnofusus) portolaensls.__....... .......... ____._ 75 

O 

Gadiniaroticulata..___.__................. . . ......... 78 

Gaffoy anticline and synollne.............................. 48-49,52,58-59, pi. 17, B 

galcata, Puncturella..__________......_.... ... ______ 61 

gallina, Togula............................................................... 61 

Gastropods....__......_.____.__.........____....._._.__ 61 

gatunonsis, Strombuscf...._._.__........._............._. 27,28,pi.28 

gausapata, Mitrolla carlnata_........_............. ......__..._ 77,pi.32 

gemma, Jaton......____......................................_... 75,pi.30 

Geography of the area....._..........___.........._._-...-.-...-.-.. 8-11 

George F Canyon area__.._.._.__......................_ 23-24, pi. 24, A 

gibbora, Calyptogona....______.........._......... .....___.... 83 

glbberosum.Pachypoma....._......................................._ 63,pi.29 

gigantcum, Bittiuin....____....._.........__._......_____.. 67 

gllbcrtl, Slphonalla.............^.....-....-.-......------------..-..._..--.. 75 

Glacial-1 ntorglacial assignments...__........._.................__._ 100-103 

Glanssubquadrata..._.___.._......................................... 82 

INDEX 141 

Page 

gloriosa, Cerithiopsis......................................................_ 69 

Glossus (Pectunculus) collinus._........................................... 79 

Glycymeridae.-_._____________.-____....____._--_._-_.---._..--__..--___... 79 

Glycymeris_................................................................ 79 

barbarensis..__............_..............._...______....._ 79 

corteziana...______....................................................... 79 

migueliana............................................................... 79 

profunda...____...__................__....._._..._I.!__ 79, pi. 30 

septentrionalis_........................................................1 79 

subobsoleta_............................................_.-.........".. 79 

veatchii....__.............__.............__._.......____.. 7& 

gnidia, Chione........................_.........._..........._.___ 84,pi.37 

Gouldiaaff. varians....._....._......'.................__...__.__ 82 

gouldii, Thyasira............................................................. 83 

gracilior, Admete._...__...._.__....__...................__...... 77 

gracilis, Trophon.......................................___............... 76 

gracillima. Tritonalia............................................._.......... 76 

grandis, Crepidula__...................................._........_;.. 70 

Pandora.............................................................. 85, pi. 33 

grantianum, Calliostoma...__................................___._ 62 

Gravel........................................................................ 120 

Gregariella. 

grippi, Caecum. 

Eupleura... 

Gyraulus....... 

Haliotidae... _. __. 

haliotiphila, Barleeia. 

Haliotis. 

cracherodii......................................................._..... 

fulgens...._____...__..........__.........____._____.. 

. rufescens.........._.........._........................._........... 

Halistylus pupoideus.-....................................................... 

harfordi, Harfordia.._......_......___...___............_.__.... 

Harfordia ..........................................................__.. 

harfordi...___.._..._....__.....__.__.__...___.__.. 

monksac_.......................................................... 73, 

hastatus, Chlamys__.......................................'......_....... 

Helisoma___.. __________...____... __....__._.__...... 

hemphilli, Fartulum_____....................................._...... 

hericius, Chlamys.._.....____......................................... 

Hilltop quarry and nearby localities................................... 49-51, 

hindsii, Chlamys islandicus_...--...-.-...........- ...................... 

Hipponicidae._________..........___._......_......_.___.. 

Hipponix..__.______..............._....... .....___ . 

antiquatus____..........................................__........ 

cranioides.-__-------.-------,.._.--.--.-..-.-----.----_._...._. 

tumens..______........___.___.......______........... 

History of the region_____.........__.___.. _____.......... 

Homalopoma......___............ ............. .._.._............... 

bacula.........___............... ......-.......-..-.-..--.-...--.... 

carpenter!.......................................................... 63-64, 

paucicostatum____................................................... 

fenestratum......_....................._......................... 

subobsoletum_______._.................._._____.__...... 

hooveri, "Nassa'' versicolor..-.....................:......................_ 

humerosa, Neptunea.........-.-.-...-..-.....-....-..-.....-...__........ 

Humilaria......__.___.....................__........__._....... 

Hyalina...................................................................... 

californica.--.__________-__.___...____.-..-..------------_----_-_. ....... 

jewettii. __...____...................................................... 

nanella..______.......__......_...._................_.. 

regularis......__.__............................. .................... 

Hyalopectenvancouverensis.-..--.-.-..__............ .................. 81, 

Hydrobia protea.__________._____ .__... *--.-....______. 

H 

80 

69 

76 

78 

61 

66 

61 

61 

61 

61 

61 

73 

73 

73 

pi. 29 

80 

78 

69 

80 

pi. 16 

80 

70 

70 

. 70 

70 

70 3 

63-64 

64 

pi. 29 

64 

64 

64 

74 

75 

84 

77 

77 

77 

77 

77 

pi. 33 

66-67 

idae, Aesopus......._.__........____..._ ._............._.... 77 

Mitra.................................................................... 73 

Igneous rocks.....--..-----.--.---.-............--.-..-...-........--....-.. 108-109 

imperforata, Neverita reclusiana.............................................. 71,72 

imperialis, Turcica.-...---.-----..............--.-.-......-.-.--...-.-....... 62 

inaequale, Pachypoma.-.___......................................._.... 63 

inclusus, Amphithalamus__................................................ 65 

indisputabilis, "Nassa" mendica... ..........................................'. 74 

inflatula, Macoma.....__................................................... 84 

insculpta, "Nassa"._......-.-.... -.........-..-..............-...- -.-... 73,pl. 29 

insessa, Acmaea.._______........___........__.___.......__ 61 

insignis, Cantharus____-.--...----........-..----....--.--..........-..... 75 

intastriata, Nassa.:......__--..._.......................................... 74 

interfossa, Bittium.._....................................^................. 67 

Tritonalia................-.-..-.-.......--....-...-.I.................... . 75 

interstriata, Nassa_..._.................................................. 74 

intorta, Olivella..-.-.-.__................................................. 77 

invallata, Pseudorotella.__........___..........................__.... 63 

Iselica fenestrata___.............................................. 65, pi. 34 

islandicus, Chlamys..-.-...-------------..-.-------------...---------___-- 80 

Jaton_._.................................................................... 75 

eldridgei.______._.-..-__.....................__.........; 75 

festivus._.____--...__.........._._........................ 75 

gemma.______._...........__........__...._._........ 75, pi. 30 

santarosanus.__._.................................................... 75 

jewettii, Haylina...__...................................................... 77 

Turritella. ............................................................. 69-70 

jordani, Chlamys islandicus..___........__...__._____..__ 80, pi. 32 

Jurassic system______-.---_-.-_...__................._---------- 12-13 

K 

Katherinella_.....__......__...___................................ 84 

subdlaphana___....__________...____.____.___ 84, pi. 33 

pedroana. 

keopi, Tritonalia__._... 

Tritonalia interfossa cf. 

Kelletia kelletii............. 

kelletii, Kelletia............ 

Macron aethiops_.... 

kelseyi, Milneria- 

Rissoina--...-...-....---.------..........-.....-..........-..--__.. 66, pi. 29 

84 

75 

75 

74 

74 

75 

83

142 INDEX 

Page 

kennerlyi, Mercenaria____ -. - - -_- -_- 84 mendica, "Nassa".._---_.--------.-.---_..-..-......-....-...--.-.___. 74 

kettlemanensis, Thais.-----___---- - . 75 Mercenaria......_.._.._..--..--.......----....-........-.--._..__.. 84 

knechti, Pupillaria optabilis_____...-..-.-....__.-.-___-..___ 62, pi. 34 kennerlyi.._________..........._.......__.......______.. 84 

Knefastia cf. K. funiculata______._______.--.__.______ 27, pi. 28 perlaminosa.-. .____.__...._____............______ 84, pi. 31 

Metamorphic rocks.______..........._.-.-....--_............__... 12-13 

T, . 

mexicana, Crassinella cf__.._...-....-.-..._.------.-.-.-...__.._ 27, pi. 28 

Mexicardia._______................._.................__.___.__ 85 

labiata, Area......_____ _,____-_...............................__ 79 Micranellum crebricinctum._............-.....-..--..-.---.--..-.....___ 69 

Clavatulacf. .--------.----------_..-._.. ----------. 27, 28,pi. 28 Microglyphis............._._ ._. -. _. ___.__......._.. 78 

Lacuna___ ___.....................................................__ 64-65 migueliana, Glycymeris.._---------.-------.-----. ......__.-..__.... 79 

carinata 

65 Milneriakelseyi.____________.______.______________ 83 

compacta__......__.--... - ... ._ ... . 

Milthasanctaecrucis.--..____..__.-....... _________-_.. 27, pi. 28 

divaricata___________ _..._ ----._ . .---_-_._.... Mineral resources....__._----------------------______........... 118-120 

porrecta... __.___.__ -....-. ._ __. _ ... .... 65 minima, Anachis. ____....__......_._________________ 77 

solidula_......______ ___,.___.___----____._._.........__...-..-.__ 65 minuscula, Cardita___._....._........._____........______ 82 

unifasciata_._............_......................................... 64 Miocene rocks, igneous..._.....I------.-....--.___......_.____ 108-109 

aurantiaca____.............................. -------------------- 64 sedimentary.-._..__........__._...___ 13-40, pis. 10, 12, A, B, 24, A 

variegata.......__...._._...............................---------- 65 Miocene structural history.--.._..-------..._......__..........._.... 109 

acunatus, Amphithalamus..___..__. -_ _ . . - 

65 Miodontiscus prolongatus......-.....-.-._..-.--...__._........__.... 82 

Lacunidae._______________........-.......-'-..---.-..-.I.--..'-..... 64-65 Miraleste area.........................................._............_.... 18,24 

Laeyicardium.._____._...... ...................................... 85 Miraleste Canyon area..........................._ ...-.___......____ 23-24 

laevigata,Velutina.......^................................................-.. 72 Miraleste tuff bed..__._............ ..._..... .. 19-20, 22-24, pi. 7, A 

Lamellaria stearnsii__ ........-----.... ...-..-.....-.-.. --.-..---------... 72 Mitra 

73 

lamellosa, Cumingia....___.................._......................_... 84 fultoni. 

73 

Nucella___________.__._.............__..............__.... 76 idae... 

73 

Landslides__.__._...-.---. --.-.-.-..-..-..--..------------..--.----- 117 Mitrella 

77 

larum, Bittium rugatum._______...............................__ 67,68, pi. 29 carinata...__ .--..-....-.-.......___.._...._................... 77 

Lasaeacistula.__________.__..............................____ 84 gausapata.__......__........_______...________. 77, pi. 32 

lasia, Trophonopsis...._______........-.-.................---.-..:.- 76, pi. 34 tuberosa . ..-.--..-..-.-.........-_------------.--._.............. 77 

latiauratus, Leptopecten_.__^......................................... 81 major.----........-..-......-....._._.........._.....__...... 77 

lepisma, Acmaea. __.__ ___..............--...............--. --.-------.-.. 61 Mitridae......_...----........-........-.._._.....___........_... 73 

lepta, Terebra (Paraterebra) cf.....-.-.-...-..-.....-...:..-...........27, 28, pi. 28 Modelia striata................_....--..--..-..-.__..._..__._._... 65 

Leptonncea........._____......_................................ 84 Modiolus opifex.__..____.................._._____......__...... 80 

Leptopccten.... __: __._............................... ... 81 Mollusks.................................... 26-28, 33, 37, 42, 60-85, 87-90, pis. 28-37 

latiauratus..._._____.... _............ _...................__ 81 Monia macroschisma._......................_ .. _..___..._ _.---. 79 

cerritensis....-_.__..........-...-...-.......-..-...-...-.....-.. 81 monilicosta, Cardita.__....'......-..-..--.-....--..-............--.......... 82 

delosi- .-__...................................................... 81 monksae, Harfordia................-..-.--....-.--.-.-....-.............I. 73, pi. 29 

inonotimeris_..___ _... ....__ 

81 monotimeris, Leptopecten latiauratus--....--..---.---.-...--..-._.-.-...-- 81 

lewisii, Lunatia...______.....__ ... ...__...--..........--.-.-.- 72 Monterey shale, age and correlation of......-.--.-.-.-.--.---..---.------.__ 40 

ligatum, Calliostoma._. . . --_.- -- . 

62 Altamira shale member of.--------.__...___ 16-33, pis. 3, 4, 6-9,10, B, 28 

ligulata, Tegula....____._...._.............._...'........-._----- 62 fossils in.................................. 16, 19, 25-28, 32-33, 35-37, 39-40, pi. 28 

limatula, Acmaea__._....-.-.-.-.-----.--------.--..------.-.--.---.-----. 61 general relations of......_-.--.-------.-.-.....-.._.._...___.... 13 

lingulata, Crepipatella__.__.........................._____...... . 71 lithology of---....__.......-.....--.------..___..........._....... 13-16 

Liotia..-......- _._....____ . ... .__............... 63 Malaga mudstone member of.-.. ._-.----..__.. 37-39, pis. 11, 17, B, 18, ,4 

acuticostata......_..................................................... 63 Valmonte diatomite member of......_......._______ 33-37, pis. 10, (7,11 

radiata.._______.__.....................____......... 63 montereyensis, Alyania__-------.-.---------...__......__..__....... 66 

fenestrata_____.....___.........................___....__. 63 Bittium eschrichtii.......___............____.....____... 67 

Liotiidae.._-.__---------_ - --- - 63 montereyi, Tegula..___..._____..-----.---_._._..._..__... 61-62 

Llrobittium.____.......__.............._..__.______-----__ 67 moraniana, "Nassa"-__..................................................... 73 

Liralaria...____..._.__....._ __......._..__........._....... 62 multicostatus, Boreotrophon aff.___.._.. .-- ._._..._................. 76 

magna.______...__................. _...__._......:..- ..- 62 Trophon_________._____........................................ 76 

Littorina. 

64 munda, Tritonalia lurida._______....__...............- - -........ 76 

pedroana. 

64 munita, Cyrilla___--.---.-...-.------.-.--.-______.......__... 78 

planaxis.. 

64 Muricidae.._____..........._.--.-.---.-.-.____________. 75-76 

plena. 

64 Mya truncata_..._........'........................................... 85, pi. 33 

scutulata.__..__._..................._ ._.____..._. 64 

Myacidae.-______--.-..__--..------.---.-..--.--__..--.-.---..-_. 85 

Littorinidae-______.___...-- _.....________.__I__.. 64 

Mytilidae.-----------_----- __-------...................._-....___. 79-80 

Hvidus, Macron...._._...___..._.___.________......__... 75 

Mytilus californianus_____..........._..........________......... 79 

lomaense, Bittiumasperum_._............................................ 68 

Lomita marl..... ......... 43-46,49,53,90-92,96,98-99, pis. 15, A, 16,17,29-31 

N 

Lomita quarry and nearby localities-__..__._....____ 41,51-52, pi. 17, A 

lomitensis, Crassaftellites_.._____-... .. . .-._........__.... 82 nanella, Hyalina jewettii.____.__.. __----- -----.. .... 77 

longinqua, Amnicola______..__.............'............---.--.-.-..-. 66 "Nassa"________________ . - .___--.----.. .. 73-74 

Lora...__..____.______._.........___._. _ - 77 californiana ___---------__..... .-.----.--. ... ... . 74 

Los Angeles Basin, correlation of formations in.. .... _._......... 103-104,105 cerritensis____...-..-.__.__..._---------------- . ..... 74, pi. 35 

oil fields of .___. .._ . 8 delosi__----.-.-'.--.-..._---._. -----..--..-.-... ...... 74, pi. 35 

Lucinidae...__.____________.............._.._...._.__... 83 fossata...________.__-.--._.__--...-.._..... .._.... 73 

Lucinoma annulata____.............-.............-...--'----_...._... 83 coilotera___-.--.-.-.-------_-----.-----.--..---.-----._..__ 73, pi. 35 

lugubris, Acanthina.____.....__.__...............__.___._ 76, pi. 35 insculpta...- __ -.. - - .--- .. ... 73, pi. 29 

LunadaBay area..........-.-.-....---..-............--.-- 21.29-30, pi. 8 intastriata___.___....__.. ..__-.-......_....________ 74 

Lunatia lewisii-..__.__.. .._ _.____ ._.......................-...-.- 72 interstriata..___...___._....... . .................... 74 

lurida, Ostrea_____.___...___ ................._-.___._... 81 mendica..._____....._-.-...---.---.----.-.---._______... 74 

Trttonalla...... .."............ . .... 75,76 cooperi.......___.._.-.--------.-..--.----.._... . . 74, pi. 34 

luteopictus, Fusinus.__________..........._____. ... ___ 73 indisputabilis___.---------..-.. ------...... ..---.--.-. ... 74 

moraniana_.__...............__...-..---.--.__.-.--.--.-...-..... 73 

pedroana--.-_____-------__---.-.------..;---.._-------__...... 77 

M 

perpinquis.- ___-------------------------- .................... 74 

Macheroplax....... 

62-63 tegula.------ ------ -----------...---... ----- - ----- 73 

varicosa........ 

63 versicolor....____.._------..-...-.--.----.--_...__.'___..... 74 

cf. M. varicosa. 

63 hooveri... ..___..._...........................:............... 74 

Macoma. 

84 woodwardi.._________________. ___... ...__.__. 74 

calcarea__________.___.................................... 84, pi. 33 Nassarius . ..__....---___ - _._ 

73 

carlottensis______ __.___............................. ........ 84 "Nassidae"--------__-----------------_... .-.. . 

73-74 

inflatula._________..._..__ __ . - .. --. -- . 84 Naticidae..-.- ----........-----.- --.--- ... ....-.- ....... ....... 71-72 

planiuscula____...__ _____......................._..--......- 84 navarchus, Chlamys -.---.-....--...-------.-------.--..-_._ ... .... 80 

Macrocallista cf. M. maculata_.___... ._._..__....... 28, pi. 28 necropolitana, Cerithiopsis.---.-.---.-...- --------- ...... 69 

Macron.._.____.._.................................................. 75 Neptunea.. ------..-.-------.--------.------ ... -..-.. 74,75 

aethlops..___...._...........-.:-.. --........-----.....-.---.-..---. 75 humerosa..._..__.._.---...-----..._-.---.-._.--....---...--.-. 75 

kelletU.-- - .- - -. - -- - 75 angulata...--____.-----.-.-...-.- ..-------.--. ....- ..... 75 

lividus_.___._________ ._. . _ _ --- -- 

75 tabulata.___________.__.--... ..__.. . 74, pi. 32 

macroschisma, Monia.--.------. .. . -- -- 79 Neptuneidae.. _.. . 

74-75 

maculata, Macrocallista cf.............-.....'...-............-....-....-... 28, pi. 28 nereina, Rissoina......._____.--.----.--------...___ ..... 66 

magna, Lirularia...__.__.__............-..-....-.--...--...-.--. ..- 62 Neverita___----.-.-.-.------ ... 

71-72 

magnum. Caecum._..__.................................................. 69 reclusiana.- ..__.____.. _... . 

71,72 

major, Mitrella tuberosa__.....---.-.--..-.--..---.-.-.--...--...--._.... ' 77 alta.______..._-.-____--._____.... ... 71,72 

Malaga Cove area................ 20-21,28-29,34-35,38,41,53,59, pis. in, A, C. 11,12 callosa..__...____-...-.- __--.-. .. 72 

Malaga mudstone member...._.._.__.....___ 37-39,40, pis. 11,17, B, 18, A imperforata_.............-...------------......----.-..------....... 71,72 

mamillaris, Calyptraea...__....................______... .. ... 71 newsomi, Pecten._.....-----.-...-..__-.. ._____.. . 80 

Mammals......____._..........................^....................... 86 nodosa, Margarita optabilis_....--.----. ........... . . .... 62 

marcida, Tegula._____. __ ..----- . _._. -.-. -.-.- -- 62 nodosus, Vermetus.-..__ --...-. . . .:.......... 69 

Margarita...-...--.__._._ ..._ _ _ . _ . 

62 nodulosa, Cyclocardia.____.__.._ __ .' 83 

optabilis nodosa.__'__.._.......___........._................. 62 Venericardia_______-..._._..-.. ..._..-.--.. --..- . 83 

parcipicta pedroana_.__.....---._......._.........-.-......--.-... 62 Nonmarine terrace cover_________._.___ 106-107, pis. 15, C, 18, B, 24, A 

Margarites.....______-.......-.-.----.---..-.-.-.-..-----......----- 62 Nucella_.. __ . .. . .. 

76 

Marginellidae..._______.__.......-..-..-..-...... _..-.-..-........ 77 biserialis . ..... . 

76 

mariae, Chione (Llrophora) aff______............- .-..-..-'.-.-..-.... 27, pi. 28 emarginata.. _ _____.. . ---... . 76 

mariana, Turritella ..__....--.-.--.-...--....-.....--.-..-..... _* ._-. 70 lamellosa----- _.--.... - __ _.- -...--.. . ... -- 76 

Marine terrace deposits.... - 53-59,93-95,96,99-100, pi. 3-5 Nucula..- ... __-. -.-.-.-.- -------- . .: .. ..... 78 

Marine terraces.......__............................. 113-116, pis. 23, 24, C, 25, 26 exigua.--..--___...___._.--.-----.--.__.. '................ 78 

marmorea, Diala.______... .- .-..- ...........__...... ...... 67 suprastriata-___-.-.. .----...-..---- ...... 78 

megodon, Ostrea.....__ __ __ ........ - ...... .... 81 petriola.-.-. .-.-.---.-----.-----.-----.... ..... ............. 78 

Melampus olivaceus___.--.--..._.-.---....-....--.-..--.....---.--..--. 78 suprastriata.. -_ .'.. ... ........ . . . . . 78 

Melanellidae._______________--..-......_..........____.... 72-73 aff. N. cardara________... __..... ;.. 78

Page 

Nuculanidao___.._____.........._....._____.....____ 78 

Nuculldao........--.--._.--------

144 INDEX 

Page 

Rissoinidae______________._._____________.______. 66 

ritteri, Trivia..____.______________________________ 72 

riversi, Pecten (Propeamussium)....._........._....._..___......... 81 

rosana, Alvania.-.-----.....-_............._.....__.._..__......._ 65 

Alvania acutelirata__.__.___________ . L_______.___ 65 

rubrilineata, Tricolia...__......._.._....................__.._._. '64 

.rufescens, Haliotis..___......---..--..........-_.........___....._. 61 

rugatum. Bittium.______.____.___.___....__._____67,68, pi. 29 

rugosa, Crepidula.-.__._...._.___.__ ....____.___._____ 71 

russa, Cryptonatica._____..____________________:___ 71 

S 

salmonea, Pupillaria_____.---.--.---.--._.--.________... _ 62 

Pupillaria cf.__.__._... .. . . . .___.__...... 62 

salvania, Vitrinella___________________...__________ 63, pi. 29 

San Diego and nearby localities..__._._...__.____._______ 105 

San Francisco Peninsula_.....-..---_..__ -....___________... 105 

San Pedro, early history of..,-..-_..........___.___________... 3 

industries of.. _________...______ ___________ - 8 

San Pedro area 24, 31, 35, 39, 46-48, 56-58, pis. 14, 15 

San Pedro Hills, name of._______-____.__________....___ 3 

San Pedro sand.-. 43-48, 50-52, 53, 92-93, 96, 98-99, pis. 12, A, B, 15, C, D, 18-20, 34 

sanctaecrucis, Miltha_____..._..__________________. 27, pi. 28 

sancti-lucovici, Aequipectencf-..--.____________._______ 27, pi. 28 

Sand.........__........................__...-.____.....__...... 120 

Santa Barbara. - rl 104-105,106 

Santa Monica..'___..__....-.-.-.....____..._.-..--..-____ 104 

santarosanus, Jaton....___......_.__._________.___..___ 75 

saugusensis, Crepidula__ -- - _-..--.....__.._-----------_. 71 

saxicola, Purpura.____.____..__.- .__................................. 76 

scabra, Acmaea. --------------__-...-..__.- ._ --._.._....-- 61 

scalariformis, Trophon___......_...................._...______... 76 

schencki, Acteon.--.-....__....._.---....-.-.--________.__ .78 

Schizopyga.__.____..__._...________-_________-___ 73 

scutulata, Littorina______....__....___.__.____________ 64 

Searlesia___.__________..........____._____________ 75 

Semelidae.................................................................... 84 

Semibittium._______._____.......________.___________ 67 

septentrionalis, Glycymeris..___......___________.________ 79 

Septifer bifurcatus..____.__....___._____.__._________ 80 

sericata, Diplodonta_______________.__._________ 83-84, pi. 36 

serra, Bittium_______._...._______._______________ 67 

setosa, Philobrya.. __......__________..___._________ 79 

Signal Hill..........._ __ 104,105 

Siphonalia.._________._________._______________ 75 

gilbert! . . = . . 75 

sisquocensis, Area...___.-.. .___-.-__.".___------.-.--..---_. 79 

Soils of the area._______________________._____.-.__ 9 

solandri, Trivia. -._ __...._..__.__....__.___ 72 

Solariella.....__._ ......... .. .. 62 

peramabilis. __._____....______ __________ 62, pi. 32 

rhyssa________.__.._._______._______________ 62 

solidula, Columbella______......___.______.____._____ 77 

Lacuna.... .._____._.___________...._________ 65 

spadicea, Cypraea __...___..____.__._._.__._ __ 72 

spinosum, Crucibulum-.. _......._..........--..... ......,.-.-.-. 71 

spirata, Acanthina.._____......__...__...._________._ 76 

squamigerus, Aletes....__.__._____.__...-- ...___ ..... 69 

squamulifera, Tritonalia __ __... .. . 76, pi. 34 

stearnsii, Cyclocardia -..._..__..._.--._ . --....---- -.. . 83 

Lamellaria.._._________ _...... . ....__ . .. 72 

Pecten..__ ........_.............L.................. 80, pis. 30, 32 

stimpsoni, Truncatella.--__..___.____..... ----.----....... 66 

stokesi, Palude'strina.__________._____ ....-... .__ 66-67 

strategus, Pecten (Chlamys) hericeus----.____ __-----__ 81 

Stratigraphy, outline of __. __ __. .. __. . .. 11-12 

Stream terrace gravel....____.......___....__.__...... __ 107 

striata, Modelia.-__________-__________________-__ 65 

Strombina___ _..._____....._.___ __ __.__ __ 77 

Strombus cf. S. gatunensis______...._._____________ 27, 28, pi. 28 

Structure . 109-113, pi. 24, A, B 

stuarti, Boreotrophon aff ______.....____._______... __ 76 

Stylidium. . .... - . .... 67 

subdiaphana, Katherinella.. ______________________._ 84, pi. 33 

subobsoleta', Qlycymeris ______-_.___ ... 79 

subobsoletum, Homalopoma_....-.--..--..-.-..--.--------__-.-..-.--.-- 64 

subplanatum, Bittium._.....,_ .......................................... 67 

subquadrata, Cardita __._.....___...__. __ .. . 82 

Qlans.. -.-- :-- 82 

subventricosus, Pecten....__. ..-.-------..-.. -...---. 80 

succincta, Pupillaria__--...__.. ._...... .._ ... .. _. 62 

supragranosum, Calliostoma . . .._ .. .. 62 

suprastriata, Nucula ... . . . .... .. 78 

Nuculaexigua . . .. .. . . 78 

supravallata, Pseudorotella.__.. .. .__ .. 63 

Syncera translucens . 66 

Synceridae. .. - - 66 

T 

tabulata, Neptunea 74, pi. 32 

Tachyrhynchus- __._____ - ... . - 68 

Taranis...- - - 77,78 

Tectibranchiates. 78 

Tegula-.... _. -.- . 61-62 

aureotincta.. ........... ...- .. . - 62 

brunnea....----------.------..-------------_..-..... ..... ..-- ._.. 61 

funebralis.. . . . . . - 61 

gallina 61 

ligulata - - ------- 62 

marcida...... - ----- --... .. 62 

montereyi._____.._.. ... - 61-62 

pulligo .... -. 62 

tegula, "Nassa". _ . . - --- 73 

Telluiidae.. . . --- ------------- 84 

Temperature facies, interpretation of. .. .. - . .... 103 

Temperature in the area..___... .... . 9 

tenuisculpta, Alabina __ v- - 67 

tenuisculptus, Trophon . 76 

Terebra. 78 

pedroana.-.. . 78 

phllippiana . - 78 

(Paraterebra) cf. lepta. ............ ... .............. 27,28, pi. 28 

Page 

Terebridae.____. ___..________________._______.. 78 

Terrace deposits.. _. ___ 53-59,93-95,96,99-100,106-107, pis. 15, C, 18, B, 24, A, 35 

Terraces. 113-116, pis. 23, 24, C, 25, 26 

Thaididae ........ _ _ ..I ...... 76 

Thais kettlemanensis.--........--.--..........--.. ...........__..._. 75 

thomasi, Vitrmella.'..........................................._.__.. .. 63 

Thracia ...- ......- ....-. ....-... ............ . _..... 85 

curta.........._......................................................... 85 

trapezoides......._......"................................ ........ 85,pi. 34 

Thraciidae.... .- ........... ...............- .................... 85 

Thyasira.-... __...... ___.........___ ......__... ...___ 83 

bisecta__-..-.-.-............---..............................'......._. 83 

disjuncta.. ..... __. _ ._............................. ...-,-- 83",pi. 33 

gouldii ------.----................... .--..... ...............--__ 83 

Thyasiridae..__.-.-___.. _........_.___....._.... __..._ 83 

Timms Point 45-46,pi. 15,B 

Timms Point silt. .. ............ 43-46,52, 92,96,98-99, pis. 15, A, B, 32,33 

Torrance oil field, location of_....._______.......______. ____ 8 

Trachycardium __.. .._...____.________.'__.____....... 84-85 

elatum... ---.....-.......-.---....... -..-.........__.__.__.. 85 

procerum.----..---.---.---------------.-----.---.------. -__- __. 85,pi. 37 

quadragenarium-----------..----------.....--- ---...---. .....- 84-85,pi. 34 

translucens, Syncera.-.._ .... ... . .... .___...._._ - ___. 66 

trapezoides, Thracia __..._....._ ... ..___._______... 85,pi. 33 

TriCDlia - .---.. .. ..... ...---..--. ....-...- .. 64 

compta_..--- ---..-----.-.---..---.-....---.-..-.....--.._......._ 64 

pulloides- .......__. . -.......... ...... .. ....... ....__ 64 

rubrilineata ....._._. _ ._ - ... ._..._ _ _ 64 

Tricoliidae - --..-.. ----- ...-.- -....-. -...-.... -........ 64 

Trigoniocardia .....__ _.._ ... ...__..___.. 27,85 

biangulata.----. ... - ....--...-.. ..-.- ._......_.__ 85,pi. 35 

aff. T. antillarum . . _ _ 27, pi. 28 

Triphora. 

fossilis. ""[-_ _ . .. _ ... -. ..... .--..--- ..-...--.......- ----------.-.-......--.....--- ___ .... ____ --_. ....- 

pedroana... ........ . . . ____ 

cf. T. pedroana...- ___ ___ ... ... ._ _ ...... ___ ...... _ . _ .... __ . 

Triphoridae -_ ------ - .......... _ . _ .............. ............ 

Tritonalia. .... .---.-... -....-.... ............. ..:...............-....,. 

barbarensis -.... _ - -- - ... ... ...... ... ... __ 

circumtexta __ .........................:................................ 

aurantia. .......................................................... ..^ 

. citrica.-.. ._ .. . . . - -- --- _ . 

coryphaena. ___._. , . . ... ....... . ........ .... ..... 76, 

foveolata. ---, - - - - _ . ._ 

fusconptata. ...-.--... .......-..............--.. -.................-. . ... 

gracillima __ ................---......... .......-....;.....-..-........ 

interfossa. .-------......-.......-...--.......-....--...........-.-........ 

keep!.. - - - -- - - i .. 

lurida..... ...... ......- . ...... ... _ . ,... . ......... ... 

aspera ................................................................ 

munda... _ _ -..---..-...-.-- -. ..--...---.-.---....-- ....-... 

poulsoni..-.. ___ . - . 

squamulifera _ ......................... ... ........................... 75, 

cf . T. interfossa keepi. . _ . _ __.- .- . - _ _ 

tritonidea, Cancellaria. .................. .-.....--..----.......-.--.-..... 76, 

Trivia.---...-----.------.---...------------.-.-.-.--..--.----.-..-------..... 

ritteri.. 

solandri. 

Trochidae- 

Trophon. 

cerritensis.--...-.--........-----..-...--.--........-...-.......-......... 

gracilis.. _J---.-...---.----.-...--.--.----....---....-..---..-.-.---.-..... 

multicostatus... . .... . . .. -_ . ._ 

scalariformis...............-......... ......-...--.... .. ....-.-.-..... 

tenuisculptus.....-.........-.--...-....-...--..--.---..----.---------.--.. 

Trophonopsislasia.--.-...--...---..-.-.-------.----.-..------.-----.--... 76, 

truncata, Mya . - . - ----- - - 85, 

Truncatella_ _ - -- - - --calif 

ornica.. _ ._ - - -- .stimpsoni 

_ ...................-..-.......-.----.-....- .--.-.--..- -... 

Truncatellidae- _ . . _.. - _ ---- - - 

tuberosa, Mitrella.__ ......__- . - - -- -.. - -- - 

tumens, Hipponix.. ....._.......................-....--...........---........ 

tumida, Acteocina.......1.................................................... 

turbanicus, Pomaulax..............................................:......... 

Turbinidae. -.-----.-------..-----------------.-.----.---.---.--.------------: 

69 

69 

69 

75-76 

75 

75 

75 

75 

pi. 30 

75 

75 

76 

75 

75 

75,76 

75 

76 

75 

pi. 34 

75 

pi. 35. 

72 

72 

72 

72 

61-63 

76 

76 

76 

76 

76 

76 

pi. 34 

pi. 33 

66 

66 

66 

66 

77 

70 

78 

63 

63-64 

62 

pi. 32 

62 

62 

85 

77-78 

Turcica_..........-.-.........--...-...---..---------....--..-.--. 

62, 

ore vis.. - 

imperialis-. . 

turgida, Panomya. 

Turridae--. ----- 

Turritella....... __ ..--... . ....... ...... ... - .-.. .-..-..-.-.... 69-70 

cooperi . - 69-70, pis. 34,35 

jewettil --. - -- - -- - --- -- -- --- 69-70 

mariana;... ----------- ...---.------------..---..-...-.-.-- ... . 70 

ocoyana.. - --.--.----.--.-------- _. . ... : - 28, pi. 28 

pedroensis----.--.------.-- -- ---- -.--- . 69-70, pis. 29, 32,34 

Turritellidae.." .--.----------..---.-------------- 

69-70 

undata, Amphissa..... ..--..- .. ... ...- . .--- --.. 77 

undosus, Pomaulax.--.... ..--.--.---..-.-...-..-----. ...-- 63, pi. 29 

Ungulinidae.- 83-84 

unifasciata, Lacuna... ... __ .. ..... .--... 64 

V 

Valmontediatomite member... ...-... .... .. ... .-- 33-37, 40, pis. 10, C, 11 

Valvata humeralis calif ornica-. _ ....... ........ . .. ..-. 65 

Valvalidae.. ------- ........ -- - --- 65 

vancouverensis, Hyalopecten. ...... .-...--...... 81, pi. 33 

varia, Diala _ ..... -. ... ................................... ... . ---- .......... 67 

varians, Crassinella.. ... .. . - ----- 82 

Qouldiaafl.. 82 

varicosa, Macheroplax..... ...... ...... . ... .-.. 63 

. Macheroplax cf . ----- - - - : ----- --- 63 

variegata, Lacuna. ............... ... . - -- 65 

veatchii, Qlycymeris _ .... 79

Page 

Velutlna lacvlgatu............................................................ 72 

Vclutlnldao................................................................... 72 

Vonericardla............-....-....-.-.--..-...-.--!---.------.-..-----.-..---- 82,83 

nodulosa...._ . ...... .. .............. .. ........... 83 

yotosl...............................-.. ...-.-..-..-.....-...--.... 82 

Vonorlclno-...--.._____._......................._._.....___... 84 

Vontrlcolafordll......................--........ ........................ 84,pi.31 

vcntrlcosa, Amphlssa................. ^ .......... ............ .77 

Oardlta........................................................... ... 82 

Gyclocardla............................................................... 82-83 

Vontura Basin_...._......_..................................... 104 

Venus.._....._........_ ............................... ........ . 84 

Vormotlclao_._.. 

Vormotus____... 

anellum.._._. 

nodosus....__. 

vcrsloolor, Amphlssa 

"Nassa"___.. 

Vertebrates.......... 

Vortloumbo_._... 

Vcslco myanidao__. 

virglnoura, VIIÎUUUIU, Calllostoma 

VXMJIV/AIAM'IU... ....-----...-----»-----.--------------------.....--- \IG 

vltolllna, Erato.......................-..-...--.-........;-. ........... 72, pi.30 

INDEX 145 

o 

Page 

Vltrinella..................................................................... 63 

eshnauri...__..__.........................................__.__ 63 

oldroyd,!.....______....................___._._____.___ 63 

salvania..--......-..........-..........---..-...-....-..-.-......-._ 63,pi.29 

thomasl................................................................... 63 

wllliamsoni_................__.................______...____ 63 

Vitrinellidae.......J.......................................................... 63 

vogdesi, Pecten...._.....__.__..................... ...___ 80,pi.35 

volcano, Fissurclla_...___.._____..................____...... 61 

W 

Whites Point area._.....-..............-....---.-.-....----.. 25,32,112, pi. 24, B 

willettl. Cerithlopsls...-.........:.........-.---..........-----....-.......... 69 

Wlllettia. 

Williamia peltoides.............. 

williamsoDi, Ccrithlopsis___... 

Vitrinella.................... 

Wilmington oil field, location of. 

woodward!, "Nassa" ..._....woodworthi, 

Admete...._..... 

yatesi, Venericardia. 

78 

68 

63 8 

74 

77 

82

GEOLOGY AND PALEONTOLOGY OF PALOS - Pubs Warehouse

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