New Data on Berriasian Biostratigraphy, Magnetostratigraphy, and Sedimentology in the Belogorsk Area (Central Crimea)

Vladimir  Arkadiev; Evgenij Baraboshkin; T.N. Bogdanova; A.G. Manikin; A.A. Feodorova; Ольга Шурекова; A. Yu. Guzhikov

The most complete composite Berriasian bio- and magnetostratigraphic section of central Crimea is characterized for the first time with a description of the contact between the carbonate Bedenekyr and ter- rigenous Bechku formations. The section contains all the standard ammonite zones: jacobi, occitanica, and boissieri. The Malbosiceras chaperi Beds are attributed to the occitanica Zone. The Berriasian section is characterized by six foraminiferal assemblages, ostracods (Costacythere khiamii–Hechticythere belbekensis and Costaythere drushchitzi–Reticythere marfenini beds), and dinocysts (Phobercysta neocomica Beds). The magnetostratigraphic section contains analogs of Chrons M17 and M16 reliably correlated with ammonite zones. On the basis of paleomagnetic data, the Berriasian section of central Crimea is correlated with coeval sections of the Mediterranean Region. The sedimenological analysis confirms accumulation of Berriasian sediments mostly in shallow shelf environments of the carbonate platform.

ISSN 0869-5938, Stratigraphy and Geological Correlation, 2015, Vol. 23, No. 2, pp. 155–191. © Pleiades Publishing, Ltd., 2015. Original Russian Text © V.V. Arkadiev, E.Yu. Baraboshkin, M.I. Bagaeva, T.N. Bogdanova, A.Yu. Guzhikov, A.G. Manikin, V.K. Piskunov, E.S. Platonov, Yu.N. Savel’eva, A.A. Feodorova, O.V. Shurekova, 2015, published in Stratigrafiya. Geologicheskaya Korrelyatsiya, 2015, Vol. 23, No. 2, pp. 43–80. New Data on Berriasian Biostratigraphy, Magnetostratigraphy, and Sedimentology in the Belogorsk Area (Central Crimea) V. V. Arkadieva, E. Yu. Baraboshkinb, M. I. Bagaevac, T. N. Bogdanovad, A. Yu. Guzhikovc, A. G. Manikinc, V. K. Piskunovb, E. S. Platonova, Yu. N. Savel’evae, A. A. Feodorovae, and O. V. Shurekovae a St. Petersburg State University, Universitetskaya nab. 7–9, St. Petersburg, 199034 Russia e-mail: arkadievvv@mail.ru b Moscow State University, Moscow, 119991 Russia c Saratov State University, ul. Astrakhanskaya 83, Saratov, 410012 Russia d All-Russian Institute of Geology, Srednii pr. 74, St. Petersburg, 199106 Russia e Research and Production Enterprise Geologorazvedka, ul. Knipovicha 11/2, St. Petersburg, 192019 Russia Received July 9, 2013; in final form, December 17, 2013 Abstract—The most complete composite Berriasian bio- and magnetostratigraphic section of central Crimea is characterized for the first time with a description of the contact between the carbonate Bedenekyr and terrigenous Bechku formations. The section contains all the standard ammonite zones: jacobi, occitanica, and boissieri. The Malbosiceras chaperi Beds are attributed to the occitanica Zone. The Berriasian section is characterized by six foraminiferal assemblages, ostracods (Costacythere khiamii–Hechticythere belbekensis and Costaythere drushchitzi–Reticythere marfenini beds), and dinocysts (Phobercysta neocomica Beds). The magnetostratigraphic section contains analogs of Chrons M17 and M16 reliably correlated with ammonite zones. On the basis of paleomagnetic data, the Berriasian section of central Crimea is correlated with coeval sections of the Mediterranean Region. The sedimenological analysis confirms accumulation of Berriasian sediments mostly in shallow shelf environments of the carbonate platform. Keywords: Berriasian, central Crimea, ammonites, bivalves, ostracods, foraminifers, palynomophs, biostratigraphy, magnetostratigraphy, sedimentology, paleomagnetism, magnetic polarity, magnetic chrons DOI: 10.1134/S0869593815020033 INTRODUCTION The Berriasian sections in the central part of the Crimean Peninsula were investigated by many researchers (Drushchits and Yanin, 1959; Kvantaliani and Lysenko, 1979; Bogdanova et al., 1981; Bogdanova and Kvantaliani, 1983; etc.); their paleomagnetic study was first conducted by V.N. Eremin in the 1980s (Molostovskii et al., 1989). The evolution of views on their subdivision is considered in detail in the recently published collective monograph (Arkadiev et al., 2012). We conducted complex bio- and magnetostratigraphic investigations of Berriasian sections in central Crimea in 2002 and 2011–2012. In 2002, a team of geologists from Moscow and Saratov State Universities examined sections near the settlements of Balki and Pasechnoe. Unfortunately, fragmentary magnetostratigraphic records were obtained only for the Pasechnoe section. No paleomagnetic measurements appropriate for interpretation of magnetic polarity were obtained for the Balki section because of insufficient sensitivity of the laboratory equipment used at that time (Yampolskaya, 2005). The joint efforts of specialists from St. Petersburg, Saratov, and Moscow State Universities and Research and Production Enterprise Geologorazvedka resulted in the complex investigation of sections in the outskirts of the settlements of Balki, Mezhgor’e, and Novoklenovo in 2011 and sections in the Enisarai Ravine and on the northern slope of the Karabi-Yaila Plateau (southsouthwest of the Balki settlement) in 2012 (Fig. 1). The field works were dedicated to the thorough description of sections (including the contact between limestones of the Bedenekyr Formation and sandy–clayey Bechku Formation first discovered at two localities in the outskirts of the Balki settlement), sampling of organic remains (ammonites, bivalves, corals) and rocks for the study of micro- (foraminifers, ostracods, dinocysts, calpionellids, spores, and pollen) and ichnofossils, paleomagnetic measurements, and sedimentological analysis. The subsequent analysis of sampled material made it possible, first, to correlate isolated outcrops between each other and compile the most complete Berriasian section for central Crimea and, second, to obtain its micropaleontological and magentostratigraphic characteristics. The lithological description of 155 156 ARKADIEV et al. Zelenogorskoe Burul’ch a R. Novoklenovo Balki 2944 2940 2420 2943 2952 Pasechnoe Yakovlevka 2948 2947 2951 Mezhgor’e 0 2949 2950 1 2 3 4 km SEA OF AZOV Crimean Peninsula Kerch Evpatoriya Feodosiya Belogorsk Sudak Sevastopol Alushta Yalta BLACK SEA Fig. 1. Location of Berriasian outcrops in the Sary-Su River basin. Numerals correspond to section numbers. the section was accomplished by E.Yu. Baraboshkin and V.K. Piskunov. The paleomagnetic data were obtained by M.I. Bagaeva, A.Yu. Guzhikov, and A.G. Manikin. Organic remains were identified by the following specialists: ammonites by V.V. Arkadiev and T.N. Bogdanova; bivalves by T.N. Bogdanova; brachiopods and echinoderms by S.V. Lobacheva; corals by I.Yu. Bugrova; crinoids by V.G. Klikushin; ostracods by Yu.N. Savel’eva; dinocysts, spores, and pollen by O.V. Shurekova; foraminifers by A.A. Feodorova; ichnofossils by E.Yu. Baraboshkin. E.S. Platonov made an attempt to find calpionellids in thin sections (200 in total), but failed. The ammonite specimen, foraminifers, and ostracods illustrated in this work (collection no. 13244) are stored at the Central Research Geological Museum (St. Petersburg); the collection of palynomorphs (no. 13220) is stored at the same place. STRUCTURE OF THE SUCCESSION In the Sary-Su River basin (Mezhgor’e–Balki– Novoklenovo settlement area) (Fig. 1), the Berriasian Stage includes (from the base upward) limestones and clayey limestones of the upper Bedenekyr Formation, siltstones and sandstones of the Bechku Formation, and sponge horizon, clays, siltstones, and biohermal limestones of the Kuchki Formation (Arkadiev, 2007). According to (Bogdanova et al., 1981), limestones of the Bedenekyr Formation cropping out south of the Balki Settlement on the Karabi-Yaila Plateau contain ammonites Pseudosubplanites ponticus (Ret.) and Berriasella jacobi (Maz.) of the jacobi zone. Unfortunately, more exact localization of these ammonite forms remains unknown. It is conceivable that E.Yu. Baraboshkin investigated the same section or its analogs on the northwestern slope of the Karabi-Yaila Plateau in the vicinity of the military camp in 1996–1997. In this area, white and pinkish upper Tithonian bioclastic limestones with Anchispirocyclina lusitanica (Egger) are overlain by white limestones at least 50–60 m thick with ammonites Berriasella sp. and Protetragonites tauricus (Kulj.-Vor.), brachiopods Loriolithyris sp., bivalves Gervilella sp. and Pinna sp., and gastropods. The Bechku Formation in central Crimea is characterized by ammonites Dalmasiceras tauricum (Bogd. et Ark.), Malbosiceras chaperi (Pict.), M. malbosi (Pict.), M. pictetiforme Tav., Neocosmoceras euthymi (Pict.), N. minutus Ark. et Bogd., Hegaratia bidi- STRATIGRAPHY AND GEOLOGICAL CORRELATION Vol. 23 No. 2 2015 NEW DATA ON BERRIASIAN BIOSTRATIGRAPHY, MAGNETOSTRATIGRAPHY chotoma Bogd. et. Kvant., Fauriella simplicicostata (Maz,), F. boissieri (Pict.), and others.1 On the basis of this ammonite assemblage, the Bechku Formation was correlated with the jacobi (Malbosiceras chaperi Beds), occitanica, and boissieri zones. No guide ammonite species were found in the Kuchki Formation developed in the Sary-Su River basin. The sponge horizon contains abundant brachiopod remains belonging to Symhythiris arguinensis (Moiss.), which is characteristic of the synonymous beds. Ammonites in the horizon are represented only by Hegaratia sp. and Spiticeras sp. In 2002, E.Yu. Baraboshkin found in its basal layer Riasanites crassicostatum (Kyant. et Lys.) together with Loriolithyris valdensis (Lor.) and Symphythiris arguinensis (Miss.). This find allows at least the base of the sponge horizon to be attributed to the crassicostatum Subzone. The siltstone member overlying the sponge horizon near the settlement of Mezhgor’e yielded rare poorly preserved ammonites: Haploceras ex gr. cristifer (Opp.), Protetragonites tauricus (Kulj.-Vor.), Spiticeras sp., and Subalpinites sp. (identifications by T.N. Bogdanova). These species of the genera Haploceras, Protetragonites, and Spiticeras occur through the entire Berriasian section of Crimea. In France, representatives of the genus Subalpinites are known from all the Berriasian zones (Le Hégarat, 1973). In Crimea, the Sualpinites taxa are described by V.V. Arkadiev (Arkadiev et al., 2012) from the occitanica Zone in the outskirts of the Balki settlement. Nevertheless, the stratigraphic position of beds and their ammonites are consistent also with their attribution to the boissieri Zone. The biohermal limestones occurring in the upper part of the section are barren of ammonite remains. Therefore, in the previously proposed stratigraphic scale (Arkadiev et al., 2012), they are conditionally attributed to the Berriasian. At the same time, finds of brachiopods Symphythiris kojnautensis (Moiss.),Weberithyris moissevi (Weber), Zeillerina baksanensis Smirn., bivalves Megadiceras koinautense Pchel., and others in this sequence have been known for a long time (Yanin and Smirnova, 1981). The correlation of these limestones with the Bel’bek River section, where similar facies and faunal assemblages occur below the undoubtedly lower Valanginan layers, allows this sequence to be attributed to the upper Berriasian Megadiceras koinautense Beds (Yanin and Baraboshkin, 2000). The upper surface of limestones is eroded and affected by karst processes; the rocks are crossed by deep (over 6 m) cracks filled with quartz sandstone. The change in the sedimentation patterns in southwestern Crimea is typical of the Berriasian–Valanginian transition. The total thickness of the Berriasian section in the Sary-Su River basin is approximately 600 m (taking into consideration gaps in observations). Unfortunately, the 1 E.Yu. Baraboshkin believes that species euthymi and minutus should be attributed to the genus Euthymiceras, and species bidichotoma and nerodenkoi, to the genus Balkites. STRATIGRAPHY AND GEOLOGICAL CORRELATION 157 section does not represent a continuous succession and is investigated in isolated outcrops correlated on the basis of faunal finds. In the examined sections, the layers dip at an angle of 10°–12° in the NNE direction. Below, we describe the lithological composition of fragments constituting the composite section, some of which are well known (outcrops 2420, 2940, 2943, 2944, 2947), while others were visited for the first time (outcrops 2948–2952). All these outcrops are located in the outskirts of the Balki, Mezhgor’e, and Novoklenovo settlements (Fig. 2). Section 2950 (44°58′36.40′′ N, 34°28′45.90′′ E; Fig. 3) M e m b e r 1 (Samples 2950/1–5). Yellowish gray bedded bioclastic wacke- to, less commonly, packstones with abundant thalassinoid burrows. Limestones contain ooids, bioclasts of brachiopod and bivalve shells, skeletal detritus, and single foraminiferal tests of the Everticyclammina virguliana–Retrocyclammina recta–Bramkampella arabica Assemblage. The thickness is 4.5 m. Section 2951 (44°58′41.40′′ N, 34′28°44.50′′ E; Fig. 3) M e m b e r 2 (Samples 2951/1–7). Wacke- and packstones similar to rocks constituting Member 1. The talus yielded ammonite Malbosiceras ex gr. malbosi (Pictet). The thin sections demonstrate abundant sections of foraminifers belonging to the Everticyclammina virguliana–Retrocyclammina recta–Bramkampella arabica Assemblage. The thickness is 12 m. Section 2947 (Enisarai; 44°58′54.80′′ N, 34°28′18.00′′ E; Fig. 3) The lower part of the section is similar to Member 2 (Samples 2947/1–9). These sediments are overlain by the following units: M e m b e r 3 (Samples 2951/9–40). Gray bedded packstones and, less commonly, wackestones (layers 10–50 cm thick) with abundant Thalassinoides burrows, skeletal detritus up to 2 mm across, and rare larger bioclasts. The boundaries between layers are wavy. The layers contain abundant ferrugenous ooids and substantially rarer marcasite concretions. The taluses from the lower and upper parts of the member yielded bivalves Prohinnites renevieri (Coq.) and Tortarctica weberae Mordv., respectively. The thin sections exhibit abundant sections of foraminifers of the Everticyclammina virguliana–Retrocyclammina recta–Bramkampella arabica Assemblage. The thickness is 63 m. Section 2949 (44°58′56.10′′ N, 34°28′59.10′′ E; Fig. 3) This section comprises five members (from the base to the top): M e m b e r 4 (Samples 2949/1–3). Thick-bedded (30–40 cm) packstones with ferruginous ooids, bioVol. 23 No. 2 2015 2943 Beds with Zeillerina baksanensis Beds with Malbosiceras chaperi 2948 2952 occitanica 2940 2949 2947 2950 jacobi 2951 Polarity Riasanites crassicostatum, Riasanites sp., Hegaratia balkensis, H. taurica, H. bidichotoma, H. nerodenkoi, Fauriella simplicicostata Kuchki Phoberocysta neocomica ? 25 15 22 24 7.6 17 23 8.4 15 22 5.5 4 Bechku Triplasia emslandensis acuta Lenticulina andromede 3 Quadratina Fauriella boissieri, Neocosmoceras euthymi, N. minutus, Hegaratia balkensis, H. bidichotoma, H. nerodenkoi, H. taurica, Haploceras carachtheis, H. cristifer, Euphylloceras serum, Leiophylloceras calypso, Bochianites neocomiensis, B. laevis, Spiticeras multiforme, S. subspitiense, S. obliquelobatum, S. cf. tenuicostatum Protetragonites tauricus, Haploceras ex gr elimatum, Lytoceras liebigi, Spiticeras sp. 21 18 9 20 8 Dalmasiceras sp. tunassica 19 4 18 5 17 0.3 16 1.65 15 3.6 14 1.5 13 2 ? 15 5.6 2 11–12 1 10 2.8 9 11.5 7–8 45 7 6 6 Dalmasiceras tauricum, Dalmasiceras sp., Malbosiceras malbosi, M. pictetiforme, Pomeliceras breveti, Subalpinites amplus, S. insolitus, Euphylloceras serum, Leiophylloceras calypso, Protetragonites tauricus 5 6.25 4 2.7 65 3 63 2 12 1 4.5 grandis Haploceras ex gr. cristifer, Protetragonites tauricus, Spiticeras sp., Subalpinites sp. 26 30 Bedenekyr Dalmasiceras tauricum 2944 Costacythere drushchitzi–Reticythere marfenini Conorboides hofkeri Neocosmoceras euthymi Textularia crimica–Belorussiella taurica B e r r i a s i a n Riasanites crassicostatum Evirticyclammina virguliana, Lenticulina Rectocyclammina recta, muensteri Bramkampella arabica Costacythere khiamii– Hechticythere belbekensis Beds with Symphythiris arguinensis Zeillerina baksanensis Symphythiris arguinensis ? 27 15 2420 Zeillerina baksanensis Hegaratia sp., Spiticeras sp. 28 30 boissieri (Yampol’skaya et al., 2006) 5 – 29 40 Lithology Gaps in sampling, m Ostracod beds Dinocyst beds Albat Formation, sequence Member Thickness, m Foraminiferal beds/ assemblages Subzone, beds with fauna (Arkadiev et al., 2012) ARKADIEV et al. Stage Zone 158 Malbosiceras ex gr. malbosi 10 50–60 >50 Malbosiceras chaperi, M. malbosi, Ptychophylloceras semisulcatum, Protetragonites tauricus Pseudosubplanites ponticus, Berriasella jacobi Fig. 2. Composite bio- and magnetostratigraphic Berriasian section of central Crimea. For legend, see Fig. 4. STRATIGRAPHY AND GEOLOGICAL CORRELATION Vol. 23 No. 2 2015 m 5 0 m 5 0 occitanica occitanica Zone Lithology ? ? ? 15 14 13 12B 12А 12 11 10 9 8 7 6 5 4 3 2 1 10 9 8 7 6 5 4 3 2 1 270 0 10 Lithology Texture Packstone m 5 0 occitanica 12 11 10 9 Paleomagnetic samples Zone Member 90 Polarity D° 1 2 3 4 5 6 7 Paleomagnetic samples 270 0 180 270 –90 –45 2015 Rudstone I° 45 90 270 –45 45 180 –90 0 90 D° 90 0 I° 159 Fig. 3. Lithological–sedimentological and paleomagnetic data on outcrops 2947–2952. For legend, see Fig. 4. Texture Grainstone 0 No. 2 Clay/wackestone Outcrop 2948 Lithology 270 Outcrop 2951 7 4A 5 1 1 Vol. 23 Polarity I° 270 –45 45 180 –90 0 90 2 1 Member D° 90 Zone Wackestone Outcrop 2950 Paleomagnetic samples Texture ? ? Texture 40 35 m 5 occitanica jacobi Floatstone Polarity 30 25 18 20 19 15 10 5 1 Outcrop 2947 Clay/wackestone Packstone Polarity Paleomagnetic samples Zone Member NEW DATA ON BERRIASIAN BIOSTRATIGRAPHY, MAGNETOSTRATIGRAPHY 5.6 6 45 4.8 6 8.3 7 5 5 7.5 Lithology Packstone 18 17 16 15 10–12(?) 14 13 9 8 7 6 5 4 3 Member Wackestone 0 STRATIGRAPHY AND GEOLOGICAL CORRELATION Outcrop 2949 Outcrop 2952 160 ARKADIEV et al. clast detritus up to 2 mm across, and rare larger bioclasts. The rocks contain intact shells of bivalves Tortarctica weberae Mordv. The thin section contains rare sections of foraminifers belonging to the Everticyclammina virguliana–Retrocyclammina recta–Bramkampella arabica Assemblage The thickness is 2.7 m. M e m b e r 5. Gray clays containing carbon detritus, ferruginous ooids, abundant foraminifers of the Everticyclammina virguliana–Retrocyclammina recta– Bramkampella arabica Assemblage, and ostracods Cytherella lubimovae Neale, Cytherelloidea mandelstami Neale, Costacythere khiamii Tes. et Rach.), C. foveata Tes. et Rach, Hechticythere belbekensis Tes. et Rach., Quasigermanites bicarinatus moravicus Pok., and others. They are accompanied by single spores and pollen grains, dinocysts of the Muderongia Assemblage, and prasinophytes. The thickness is 0.25 m. Further, there is an unexposed interval 6 m wide. M e m b e r 6 (Samples 2949/4–5). Light gray bedded marlstones (layers of approximately 20 cm thick) with foraminifers of the Everticyclammina virguliana– Retrocyclammina recta–Bramkampella arabica Assemblage with calcareous forms characterized by dwarfish sizes. The ostracod assemblage consists of Cytherella krimensis Neale, C. lubimovae Neale, C. fragilis Neale, and others. The microfossils include also single spores, pollen, and dinocysts of the Muderonia assemblage. The thickness is 1.2 m. There is an unexposed interval 4.8 m wide. M e m b e r 7 (Samples 2949/6–7). Light gray clayey limestones with Thalassoinoides burrows and single ferruginous ooids. The thin sections exhibit single sections of foraminifers from the Everticyclammina virguliana–Retrocyclammina recta–Bramkampella arabica Assemblage. The thickness is 1 m. There is an unexposed interval 3 m wide. M e m b e r 8 (Samples 2949/8–10) is poorly exposed, being represented by isolated outcrops of gray wacke- and packstones 0.3–0.4 m thick with ferruginate ichnofossils (Thalassinoides?), skeletal detritus, unidentifiable bivalve shells, and ferruginous oolites. The two upper layers enclose lenses of shelly floatstones. The thin section demonstrates single foraminifers belonging to the Everticyclammina virguliana–Retrocyclammina recta–Bramkampella arabica Assemblage. The thickness is 3 m. Section 2948 (44°59′00.06′′ N, 34°29′10.50′′ E; Fig. 3) The section comprises seven members (from bottom to top): Member 9 (Samples 2948/6–7) is poorly exposed, being represented by two outcrops of gray wacke- and packstones (0.2–0.3 m thick) with rare Thalassinoides burrows. Thin sections yield foraminifers of the impoverished Everticyclammina virguliana– Retrocyclammina recta–Bramkampella arabica Assemblage and ostracods represented by Costacythere andreevi Tes., C. khaimii Tes. et Rach., Quasigermanites bicarinatus moravicus Pok., and others. They are accompanied by dinocysts from the Mudergonia Complex, Systematophora areolata Klement, Kleithriasphaeridium eoinodes (Eisenback), Prolixosphaeridium parvispinum (Deflandre), Achomosphaera sp., and Cometodinium habibii Montail. The thickness is 11.5 m. There is an unexposed interval 2.7 m wide. M e m b e r 10 (Samples 2948/2–5) is composed of gray clays (layers 20–50 cm thick) with intercalations of dark clays (up to 2–3 cm). Some levels yielded ferruginate unidentifiable casts of gastropod and bivalve shells. The middle part of the member encloses a single lens-shaped intercalation of light gray grainstones with gastropod shells, impoverished Everticyclammina virguliana–Retrocyclammina recta–Bramkampella arabica foraminiferal assemblage dominated by simple lituolids and poorly preserved Lenticulina tests, and ostracods Costacythere khaimii Tes. et Rach. and others. The thickness is 2.8 m. M e m b e r 11. Yellowish gray slightly consolidated sandstone with foraminifers of the Everticyclammina virguliana–Retrocyclammina recta–Bramkampella arabica Assemblage and ostracods Costacythere khiamii Tes. et Rach., Hechticythere belbekensis Tes. et Rach., Schuleridea ex gr. juddi Neale, and others. The thickness is 0.2 m. M e m b e r 12 (Sample 2948/1) is composed of horizontally bedded mixed carbonate–terrigenous sandstones with an incised channel filled with trough cross-bedded sediments containing bivalve shells, which are oriented parallel to bedding surfaces and saturate some laminae. The sandstones contain rare crustacean Ophiomorpha sp. burrows. Bivalves are represented by Prohinnites renevieri (Coq.) and Entolium germanicum (Woll.). The member yielded also a fragment of ammonite Fauriella (?) sp. and foraminifers of the impoverished Everticyclammina virguliana–Retrocyclammina recta–Bramkampella arabica Assemblage age dominated by simple lituolids and poorly preserved Lenticulina tests, ostracods Costacythere khiamii Tes. et Rach., Hechticythere belbekensis Tes. et Rach., Schuleridea ex gr. juddi Neale, and others, and dinocysts Spiniferites ex gr. ramosus (Ehren.). The thickness is 0.8 m. Section 2952 (44°59′09.24′′ N, 34°28′13.36′′ E; Fig. 3) Similar to Section 2948, this section 2952 encloses the contact between the calcareous and terrigenous sequences. On the basis of this feature, its lower part is correlated with the former section. M e m b e r 9 (Samples 2952/1–3) is poorly exposed, being represented by isolated outcrops of gray wacke- and packstones 0.2–1.0 m thick with thalassinoid burrows, ferruginous ooids, bioclast detritus up to 2 mm across, less common larger biocalsts, and intact bivalve shells. The sediments are frequently ferruginate along bedding surfaces. The thickness is 11.5 m. STRATIGRAPHY AND GEOLOGICAL CORRELATION Vol. 23 No. 2 2015 NEW DATA ON BERRIASIAN BIOSTRATIGRAPHY, MAGNETOSTRATIGRAPHY There is an unexposed interval 4 m wide with a single intercalation of packstone, which represents presumably an analog of grainstone in Member 10 (Sample 2952/4) of Section 2948. The thin sections exhibit single sections of foraminifers Melathrokerion spirialis Gorb. M e m b e r 13 (Samples 2952/5–6) is composed of light greenish gray calcareous clays with sand admixture, carbon detritus, intact unidentifiable casts of bivalve shells, and their fragments. The rocks contain the foraminifers of the Lenticulina muensteri Assemblage. Many Lenticulina shells are poorly preserved. Simple lituolids demonstrate gigantism. The ostracod assemblage includes Costacythere khiamii Tes. et Rach., C. foveata Tes. et Rach., Hechticythere belbekensis Tes. et Rach., and others. Microphytoplankton is represented by unidentifiable proximate dinocysts and prasinophytes. The thickness is 2 m. M e m b e r 14 (Sample 2952/7) is represented by light gray bioturbated floatstones with intact unidentifiable bivalve casts covered by vague encrustations and shell detritus. The thickness is 0.7 m. There is an unexposed interval 0.75 m wide. M e m b e r 15 (Samples 2952/8–10) consists of greenish gray calcareous clays with abundant carbon detritus, shelly detritus, and ferruginate structures (bioturbation?). Accumulations of bivalve shells form coquina. Bivalves are represented by Gervillella anceps (Desh. et Leym.), Neithea simpliex Mordv., and Integricardium deshayesianum (Lor.). Up the section, clays become sandy and contain abundant solitary corals Montlivaltia crimea Kusm. The upper 0.5 m of the member is poorly exposed and contains carbon detritus, and single unidentifiable remains of ammonites, belemnites, bivalves Gervillella anceps (Desh. et Leym.) and Neithea simpliex Mordv., and foraminifers of the Lenticulina muensteri Assemblage with single planktonic forms. The representatives of this assemblage are dwarfish and abnormal in shape. Many Lenticulina and Hoeglundina tests are poorly preserved. The ostracod assemblage includes Costacythere khiamii Tes. et Rach., C. foveata Tes. et Rach., C. drushchitzi (Neale), and other species. There are also spores of Schizaleales ferns Lygodium sp. and bisaccate coniferous and Classopollis spp. pollen. The thickness is 3.6 m. M e m b e r 16 (Sample 2952/11) is poorly exposed, being represented by sandy floatstones with unidentifiable bivalve shells. The thickness is 0.4 m. There is an unexposed interval 1.65 m wide. M e m b e r 17 (Sample 2952/12) is composed of slightly calcareous clays with carbon detritus, shelly detritus, and ferruginate structures (sediment feeding burrows?). The foraminiferal Lenticulina muensteri Assemblage includes dwarfish forms. Ostracods are represented by Cytherella krimensis Neale, C. flexuosa Neale, Pontocypris felix Neale, and other species. The sediments contain also bisaccate coniferous pollen. The thickness is 0.3 m. STRATIGRAPHY AND GEOLOGICAL CORRELATION 161 There is an unexposed interval approximately 5.6 m wide. M e m b e r 18 (Samples 2952/12A–15) consists of weathered pack- and wackestones with vague (due to poor exposure) clay intercalations (5–15 cm thick). The pack- and wackestones demonstrate thalassinoid burrows, skeletal detritus, and single ferruginous ooids. They contain foraminifers of the Everticyclammina virguliana–Retrocyclammina recta–Bramkampella arabica Assemblage dominated by Melathrokerion spirialis Gorb. The ostracod assemblage includes Cytherella lubimovae Neale, Cytherelloidea mandelstami Neale, Costacythere khiamii Tes. et. Rach., C. foveata Tes. et Rach., Hechticythere belbekensis Tes. et Rach., Reticythere marfenini Tes. et Rach., Schuleridea ex gr. juddi Neale, and other forms. The middle part of the member is unexposed (interval 1.2 m wide). The thickness is 5 m. The X-ray phase analysis of clay samples from Sections 2948, 2949, and 2952 revealed that all of them are characterized by a practically identical composition: quartz, calcite, and minerals of the kaolinite group, mica, chlorite, rarely albite, anorthite, and gibbsite. A single sample yielded dolomite. The samples were analyzed with a Rigaku MiniFlex II diffractometer. Section 2944 (Novoklenovo; 44°59′46.80′′ N, 34°30′16.40′′ E; Fig. 4) M e m b e r 19 (Samples 2944/1–3) is largely composed of yellow to brown unconsolidated clayey siltstones and brownish gray clays. The lower part of analogs of this member near the Balki settlement contains an intercalation of brown calcareous sandstones (0.4 m thick) with compact marlstone concretions, which yielded ammonites Malbosiceras chaperi (Pict.), M. malbosi (Pict.), and others; bivalves Entolium germanicum (Woll.), Aetostreon subsinuatum Leym., and Integricardium deshayesianum (Lor.); and brachiopods Sellithyris cf. uniplicata Smirn. The thickness is 4 m. M e m b e r 20 (Samples 2944/4–9, Novoklenovo; Samples 2940/1–7, Balki) consists of brown clays and siltstones with marlstone concretions. Near the Novoklenovo settlement, the member yielded ammonites Dalmasiceras tauricum Bogd. et Ark. and its analogs near the Balki settlement, Dalmasiceras tauricum Bogd. et Ark., Malbosiceras malbosi (Pict.), M. pictetiforme Tav., Pomeliceras breveti (Pom.), Subalpinites amplus Ark., S. insolitus Ark. and others; bivalves Pycnodonte weberae Yanin; and brachiopods Loriolithyris cf. valdensis (Lor.) and Sellithyris ex gr. gratianopolitensis (Pict.). The member contains also diverse microfossils: foraminifers of the Quadratina tunassica Assemblage; ostracods Cytherelloidea flexuosa Neale, Pontocyprella nova Neale, Cypridea funduklensis Tes. et. Rach., Acrocythere alexandrae Neale et Kolp., and other forms; single spores and Classopollis spp. pollen; dinocyst of the Phoberocysta neocomica Assemblage; prasinophytes; and acritarchs. The thickness is 8 m. Vol. 23 No. 2 2015 Polarity Paleomagnetic samples Lithology Member Zone 162 Lithology D° 270 20 28 boissieri 15 9m 30 m 25 45 90 Bivalves Calcareous clay Brachiopods Siltstone Ammonites Sandstone Gastropods Calcareous sandstone Quartz conglomerate Limestone 10 26 90 180 270 –90 –45 0 Clay 5 1 65 25 Corals Belemnites Bioclasts Clayey limestone Plant detritus Reefal limestone Skeletal detritus Sponge limestone Large plant remains 60 22 m 24 boissieri 17 m 23 55 50 45 Coquina 40 Silty marlstone 35 Marlstone concretions Marcasite concretions Ferruginous ooids Marlstone 15 m 30 25 22 4m 10 9m 5 20 No. 2 m 5 1 Lithology 15 occitanica Zone Member occitanica Vol. 23 Outcrop 2940 21 Polarity Paleomagnetic samples 20 Outcrop 2944 Stratigraphic unconformities or erosional surfaces 9 20 19 1 0 2015 Fig. 4. Lithological–sedimentological and paleomagnetic data on outcrops 2940, 2943, and 2944. Ichnofossils Thalassinoides Unidentifiable ichnofossils Structures Trough cross bedding Geomagnetic polarity Normal polarity of geomagnetic field Reverse polarity of geomagnetic field Abnormal polarity of geomagnetic field Data on polarity omitted from consideration No data on polarity ARKADIEV et al. STRATIGRAPHY AND GEOLOGICAL CORRELATION Outcrop 2943 ?m 27 0 I° Fossils NEW DATA ON BERRIASIAN BIOSTRATIGRAPHY, MAGNETOSTRATIGRAPHY Section 2940 (Balki; 44°59′21.94′′ N, 34°28′07.11′′ E; Fig. 4) M e m b e r 21 (Samples 2940/8–23) comprises dark gray, dark brown, and brown-gray (dominant) clays with rare marlstone concretions and greenish gray calcareous siltstones. In its middle part, the member encloses several intercalations (0.15–0.20 cm thick) of calcareous siltstones representing oyster accumulations with Pycnodonte weberae Yanin. The member contains diverse macro- and microfossils: ammonites Dalmasiceras sp. in its lower part; ammonites Protetragonites tauricus (Kulj.-Vor.), Haploceras ex gr. elimatum (Opp.), Lytoceras liebigi (Opp.), and Spiticeras sp. in the upper part; bivalves Entolium germanicum (Woll.), Spondylus complanatus (d’Orb.), and others; brachiopods Loriolithyris valdenses (Lor.), Sellithyris uniplicata Smirn., Belbekella airgulensis Moiss, and other species; foraminifers of the Triplasia emslandensis acuta Assemblage (some layers contain giant agglutinated forms and planktonic species); ostracods Pontocypris cuneata Neale, Acrocythere alexandrae Neale et Kolp., Costacythere khiamii Tes. et Rach., Hechticythere belbekensis Tes. et Rach., and Reticythere marfenini Tes. et Rach.; single spores including Schizaleales ferns Cicatricosisporites sp. and pollen of Classopolllis spp.; dinocysts of the Phoberocysta neocomica Assemblage. The thickness is 18 m. M e m b e r 22 (Samples 2940/24–33) is composed of dark greenish gray and brown (dominant) viscous clays and dark gray and brownish siltstones. The member contains different organic remains scattered through its entire sections: abundant small ferruginate casts of ammonites Neocosmoceras euthymi (Pict.), N. minutus Ark. et Bogd., Hegaratia bidichotoma (Bogd. et Kvant.), H. nerodenkoi (Bogd. et Kvant.), H. balkensis (Bogd. et Kvant.), Spiticeras multiforme Djan., S. subspitiense (Uhl.), S. obliquelobatum (Uhl.), Bochinites neocomiensis (d’Orb.), B. laevis Liu, and others (Fauriella boissieri (Pictet) from the collection by V.V. Drushchits originates likely from the same member); bivalves Pycnodonte weberae Yanin, Aetostreon subsinuatum (Leym.), and others; brachiopods Loriolithyris valdensis (Lor.), Symphythiris arguinensis (Moiss.), Terebratuliopsis quadrata quadrata Smirn., and other forms; rare foraminifers from the impoverished Triplasia emslandensis acuta assemblage; ostracods Cytherelloidea flexuosa Neale, Bythoceratina ex gr. variabilis Donze, Eucytherura aff. trinodosa Pok., and others; spores of Schizaleales ferns Cicatricosisporites sp., pollen of Classopolllis spp., and prasinophytes. The thickness is 5.5 m. M e m b e r 23 (Samples 2940/34–44) is represented by dark greenish gray and brown clays alternating with dark gray siltstones. The member contains the impoverished Triplasia emslandensis acuta Assemblage with dominant Spirillina kubleri Mjatl. and ostracods Cytherella krimensis Neale, C. fragilis Neale, and others. The thickness is 8.4 m. M e m b e r 24 (Samples 2940/45–58) consists of dark gray and brown clays alternating with brown calcareous siltstones. The rocks contain ammonites STRATIGRAPHY AND GEOLOGICAL CORRELATION 163 Riasanites crassicostatum (Kvant. et Lys.), Riasanites sp., Hegaratia taurica (Bogd. et Kvant.), H. bidichotoma (Bogd. et Kvant.), and others and brachiopods Loriolithyris valdensis (Lor.), Symphythiris arguinensis (Moiss.), Terebratuliopsis quadrata quadrata Smirn., and other forms. In addition, ammonite Faurella simplicostata (Maz.) was found by B.T. Yanin in this member. The member under consideration contains also the impoverished foraminiferal Triplasia emslandensis acuta Assemblage dominated by agglutinated forms and ostracods represented by Cytherella lubimovae Neale, C. fragilis Neale, Costacythere andreevi Tes., and others. The thickness is 7.6 m. M e m b e r 25 (sponge horizon, Samples 2940/59– 65) in the outskirts of the Balki settlement is characterized by the following structure (from the base upward): (1) Greenish gray unconsolidated clays (approximately 5 m) with abundant brachiopod Symphythiris arguinensis (Moiss.) remains, foraminifers of the Triplasia emslandensis acuta Assemblage dominated by Lenticulina macra Coup., Spirillina kubleri Mjatl. accompanied by single planktonic forms, spores of Schizaleales ferns Cicatricosisporites sp. and pollen of Classopolllis spp., dinocysts Systematophora areolata Klement and Phallocysta elongata (Beju), prasinophytes, and acritarchs. (2) Light gray compact clotted limestones with abundant sponge skeletons, small oysters Aetostreon subsinuatum (Leym.), spines of echinoderms Diplocidaris (?) bicarinata Web., gastropods, and other organic remains such as brachiopods Loriolithyris valdensis (Lor.) and Symphythiris arguinensis (Moiss.), single ammonites Riasanites crassicostatum (Kvant. et. Lys.), and belemnite rostra. The limestones constitute isolated bioherms 1.0–1.5 m across submerged into the matrix of greenish clays. The thickness is at least 10–12 m. (3) Alternating greenish gray clays and compact gray calcareous siltstones (4–6 m) crossed by abundant vertical Ophiomorpha and Thalassinoides burrows. The sediments contain single weathered pyrite concretions. The impoverished Triplasia emslandensis acuta foraminiferal assemblage is dominated by agglutinated forms accompanied by poorly preserved calcareous tests. (4) Greenish gray unconsolidated clays (5 m) with ammonites Hegaratia sp. and Spiticeras sp. The Lenticulina andromede foraminiferal assemblage includes single specimens of planktonic forms. Ostracods scattered through the entire sponge member are represented by the following species: Cytherella krimensis Neale, C. lubimovae Neale, Cytherelloidea flexuosa Neale, Neocythere pyrena Tes. et Rach. The integral thickness of the member is 28 m. Vol. 23 No. 2 2015 164 ARKADIEV et al. Section 2943 (Mezhgor’e; 44°58′49.95′′ N, 34°24′27.60′′ E; Fig. 4) Samples 2943/1–5 were taken in the upper part of Member 25. The overlying sediments of Member 26 remained unsampled. M e m b e r 26 (Samples 2943/6–13 were taken in the uppermost part of the member; samples for paleomagnetic measurements were taken from this member in 2002 in section 2420 near the Pasechnoe settlement located 600–700 m northeast of Section 2943) is composed of greenish gray unconsolidated clays and yellowish gray fine-grained sandy siltstones. Higher in the section, siltstones become progressively more calcareous to grade into marlstones. The member contains diverse organic remains: poorly preserved ammonites Haploceras ex gr. cristifer (Opp.), Protetragonites tauricus (Kulj.-Vor.), Spiticeras sp., and Subalpinites sp.; abundant bivalves Gervillella cf. terekensis (Renng.), Entolium germanicum (Woll.), Chlamys goldfussi (Desh.), Neithea neocomiensis (d’Orb.), N. simplex Mordv., Plagiostoma dubisiensis (Pict. et Camp.), Ceratostreon minos (Coq.), Aetostreon subsinuatum Leym., and others; brachiopods Loriolithyris valdensis (Lor.), Terebratuliopsis quadrata quadrata Smirn., Weberithyris moisseevi (Web.), and others; echinoderms Acrocidaris minor Ag., Rhabdocidaris aff. burganensis Web., and Diplocidaris (?) bicarinata Web.; crinoids Apiocrinus cf. valangiensis Lor. Sediments from the lower part of the member contain foraminifers of the Lenticulina andromede Assemblage; in its upper part, the latter is replaced by the Conorboides hofkeri Assemblage. Ostracods are represented by the following species: Cytherelloidea mandelstami Neale, Bairdia menneri Tes. et. Rach., B. kuznetsovae Tes. et. Rach., Cypridea funduklensis Tes. et Rach., Eucytherura paula Lueb., Neocythere dispar Donze, Costacythere drushchitzi (Neale), and others. There are also spores of Schizaleales ferns and other plants, Classopollis spp. pollen, dinocysts of the Phoberocysta neocomica Assemblage, prasinophytes, and acritarchs. The thickness is 30 m. M e m b e r 27 (Samples 2943/14–15) consists of light gray and yellowish gray massive and slightly consolidated marlstones. Its upper part is characterized by diverse benthic macrofossils; corals; brachiopods Terebratuliopsis quadrata quadrata Smirn., Weberithyris moisseevi (Web.), Zeillerina baksanensis Smirn., and others; bivalves Chlamys goldfussi (Desh.), Neithea atava (Roem.), N. neocomiensis (d’Orb.), Ceratostreon minos (Coq.), and others; echinoderms Rhabdocidaris aff. burganensis Web. and Pygopyrina incisa (Ag.); and crinoids A. neocomiensis (d’Or.). In 2002, E.Yu. Baraboshkin found in this member brachiopods Loriolithyris valdensis (Lor.), Cyclothyris rectimarginata Smirn., Septaliphoria gerassimovi Moiss., Symphythiris koinautensis (Moiss.), Advenina villersensis (Lor.), and other species. The sediments contain also the impoverished foraminiferal association with Textularia crimica (Gorb.) and dominated by simple lituolids. The thickness is 15 m. M e m b e r 28 (Samples 2943/16–20) is represented by light brown-gray compact clotted biohermal limestones with frequent accumulations of brachiopods Zeillerina baksanensis Smirn. and others in the lower part of the member, where they form coquinas, and abundant rudists in its upper part. Bioherms 1.5– 2.0 m high are formed by corals, rudists, and algae and surrounded by organogenic–detrital and detrital limestones. The thickness is 25–30 m. The Zeillerina baksanensis Beds are barren of guide ammonite species; therefore, many researchers considered them Valanginian (Drushchits and Yanin, 1959; Gorbachik et al., 1975). Subsequently, limestones were attributed to the Megadiceras koinautense Beds, which were dated back to the late Berriasian (Yanin and Baraboshkin, 2000). The biohermal limestones of the Kuchki Formation near the Mezhgor’e settlement are overlain with the karst- and erosion-affected surface by quartz conglomerates (5–40 m), which may likely be considered as analogous to the Albat Member of the Bel’bek River basin, where it is, in turn, overlain by lower Valanginian strata (Yanin and Baraboshkin, 2000). Near the Mezhgor’e settlement, the surface of limestones is similarly uneven and bears indications of activity of borers. The conglomerates are overlain by a sandstone and clay sequence, which is overlain near the Balki settlement by oncolitic limestones with gastropods and rudists. In the opinion of T.N. Bogdanova in (Bogdanova et al., 1981), the conglomerates are replaced west of the Mezhgor’e settlement by white gastropod limestones, which are traceable up to the Petrovo settlement. BIOSTRATIGRAPHY Ammonites. Of extreme interest is the finding of ammonite Malbosiceras ex gr. malbosi (Pictet) (Plate I) in the carbonate Bedenekyr Formation that underlies the terrigenous Bechku Formation in the outskirts of the Balki settlement (Section 2951). This ammonite was found in talus stratigraphically below the Malbosiceras chaperi Beds. The last unit defined by V.V. Arkadiev and T.N. Bogdanova in the Sary-Su River basin was correlated with the upper part of the jacobi Zone above the grandis Zone (Arkadiev et al., 2002, 2006). Previously, these sediments defined as the Malbosiceras (?) sp. Beds were attributed to the occitanica Zone (Bogdanova et al., 1981). Their correlation with any of these zones was ambiguous. V.V. Arkadiev identified from these beds M. malbosi (Pictet) together with M. chaperi. In Berriasian sections of Western Europe, the species M. malbosi is characteristic of the boissieri Zone (paramimounum Subzone), while M. chaperi occurs in the upper part of the jacobi Zone (Le Hégarat, 1973; Tavera, 1985). In Crimea, M. malbosi is, in addition, documented in the occitanica STRATIGRAPHY AND GEOLOGICAL CORRELATION Vol. 23 No. 2 2015 NEW DATA ON BERRIASIAN BIOSTRATIGRAPHY, MAGNETOSTRATIGRAPHY 165 Plate I (a) (b) 1 cm Plate I. Malbosiceras ex gr. malbosi (Pictet), specimen 1/13244. (a) Ventral view (×0.7); (b) lateral view (×0.7); Balki settlement, Member 2, Berriasian, occitaniica Zone. Zone (Arkadiev et al., 2012). Therefore, it is more reasonable to assume that it occurs at the lower level up to the jacobi Zone, not that M. chaperi continues occurring up to the occitanica Zone. In such a situation, the find of Malbosiceras ex gr. malbosi indirectly correlates the carbonate part of the examined section with the occitanica Zone. Magnetostratigraphic data, which register reverse polarity in outcrops 2950 and 2951 (Fig. 3), are consistent with correlation between the STRATIGRAPHY AND GEOLOGICAL CORRELATION Malbosiceras chaperi Beds and occitanica Zone. In the paleomagnetic scale, Chron M17 corresponds to the upper part of the jacobi Zone and largest part of the occitanica Zone (Ogg and Hinnov, 2012). Bivalves. The identified bivalve remains include both guide and marker species. In (Arkadiev et al., 2012), B.T. Yanin defined in the Berrisian Stage of Crimea three stratigraphic assemblages: lower–middle Berriasian, middle Berriasian, and upper BerriaVol. 23 No. 2 2015 166 ARKADIEV et al. sian. Neithea simplex Mord. is a guide form for the lower assemblage. This species is characteristic of Berriasian strata of Kopetdag, Mangyshlak, and the northern Caucasus, in addition to the Crimean Mountains. Prohinnites renevieri (Coq.) occurs from the lower strata of the Berriasian Stage and characterizes its entire section in Crimea. Entolium germanicum (Woll.) is also characterized by a wide stratigraphic range occurring beyond the limits of the Berriasian Stage. At the same time, in Crimea this species appearing in the jacobi Zone forms peculiar coquinas in clayey sediments of the central Crimean Mountains; i.e., it represents a marker species for this part of the region under consideration. The species is less characteristic of the middle and upper parts of the Berriasian Stage, where it occurs as single specimens. Gervillella anceps (Desh. in Leym.) and Integricardium deshayesianum (Lor.) are characteristic species of the upper middle Berriasian Dalmasiceras tauricum Subzone and largest part of the upper Berriasian. In sections of the Bel’bek River basin in southwestern Crimea, the first species (marker) forms coquinas. The second species is less frequent and never forms coquinas, being mostly distributed in the middle part of the Berriasian Stage in this area of the Crimean Mountains. Tortarctica weberi Mord. is also abundant in the same layers of the Berriasian section. Foraminifers. These microfossils from Berriasian sediments of central Crimea (Plate II) were investigated in residues and thin sections using variably oriented sections. For samples from some levels, shells extracted from rocks were used for preparing polished sections. In total, foraminifers from the composite Berriasian sec- Plate II. Foraminifers from Berriasian sediments of central Crimea. Magnification: ×20 for figs. 1–25, ×35 for figs. 26–49, ×60 for fig. 50. (1) Haplophragmium subaequale (Mjatl.), specimen 27/1324: (1a) lateral view, (1b) peripheral view, (1c) polished thin section, Balki settlement, Member 18; (2, 3) Charentia evoluta Gorb: (2) specimen 31/1324: (2a) lateral view, (2b) peripheral view, Enisarai Ravine, Member 9; (3) specimen 32/1324, thin section, transverse section, Enisarai Ravine, Member 1; (4, 5) Stomatostoecha compressa Gorb.: (4) specimen 35/1324: (4a) lateral view, (4b) peripheral view, Enisarai Ravine, Member 9; (5) specimen 36/1324, thin section, transverse section, Enisarai Ravine, Member 1; (6–8) Stomatostoecha enisalensis Gorb.: (6) specimen 38/1324, thin section, transverse section, Balki settlement, Member 18; (7) specimen 39/1324, oblique section close to the longitudinal one, Enisarai Ravine, Member 1; (8) specimen 37/1324: (8a, 8b) lateral view, (8c) peripheral view, Enisarai Ravine, Member 11; (9, 10) Melathrokerion spirialis Gorb.: (9) specimen 33/1324: (9a, 9b) lateral view, (9c) peripheral view, Balki settlement, Member 18; (10) specimen 34/1324, thin section, transverse section, Enisarai Ravine, Member 1; (11) Rectocylammina chouberti Hott., specimen 48/1324: (11a) lateral view, (11b) apertural view, (11c) polished section, Enisarai Ravine, Member 5; (12) Rectocylammina recta Gorb., specimen 52/1324: (12a) lateral view, (12b) apertural view, (12c) polished section, Enisarai Ravine, Member 10; (13) Rectocylammina arrabidensis Remalho, specimen 46/1324: (13a) lateral view, (13b) apertural view, (13c) polished section, Enisarai Ravine, Member 11; (14, 16) Everticyclammina virguliana (Koechl.): (14) specimen 44/1324: (14a) lateral view, (14b) apertural view, (14c) polished section, Enisarai Ravine, Member 5; (16) specimen 42/1324, lateral view, Enisarai Ravine, Member 6; (15) Everticyclammina elongata Gorb., specimen 45/1324, polished section, Enisarai Ravine, Member 4; (17) Alveosepta jaccardi (Schrodt), specimen 62/1324: (17a, 17b) lateral view, (17c) peripheral view, Balki settlement, Member 18; (18) Amijiella amiji (Henson), specimen 54/1324, thin section, longitudinal section, Enisarai Ravine, Member 4; (19) Bramkampella arabica Radm., specimen 55/1324, thin section, longitudinal section, Enisarai Ravine, Member 11; (20, 21) Textularia crimica (Gorb.), specimen 56/1324: (20a) lateral view, (20b) apertural view, Mezhgor’e settlement, Member 26; (21) specimen 57/1324, thin section, longitudinal section, ibid; (22–24) Belorussiella taurica Gorb.: (22) specimen 58/1324, lateral view, Mezhgor’e Settlement, Member 26; (23) specimen 59/1324, thin section, ibid; (24) specimen 60/1324, thin section, ibid; (25) Triplasia emslandensis acuta Brat. et Brand, specimen 30/1324: (25a, 25b) lateral view, (25c) apertural view, Balki settlement, Member 21; (26) Lenticulina ongkodes Esp. et Sigal, specimen 66/13244, Balki settlement, Member 21; (27) Lenticuina aquilonica Mjatl., specimen 67/13244: (27a) lateral view, (27b) peripheral view, Enisarai Ravine, Member 15; (28) Lenticulina aff. uspenskajae K. Kuzn., specimen 68/13244: (28a) lateral view, (28b) peripheral view, Enisarai Ravine, Member 15; (29) Lenticulina muensteri (Roemer), specimen 63/13244: (29a) lateral view, (29b) peripheral view, Mezhgor’e settlement, Member 26; (30) Lenticulina andromede Esp. et. Sigal, specimen 64/13244: (30a) lateral view, (30b) peripheral view, Mezhgor’e settlement, Member 26; (31) Lenticulina colligoni Esp. et Sigal, specimen 65/13244: (31a) lateral view, (31b) peripheral view, Enisarai Ravine, Member 15; (32) Lenticulina bifurcata Bart. et Brand, specimen 69/13244: (32a) lateral view, (32b) peripheral view, Enisarai Ravine, Member 15; (33) Lenticulina sp. (L. sp. 1 Gorb.), specimen 80/13244: (33a) lateral view, (33b) peripheral view, Balki settlement, Member 21; (34) Lenticulina macra Gorb., specimen 70/13244: (34a) lateral view, (34b) peripheral view, Enisarai Ravine, Member 13; (35) Lenticulina fracta Esp. et Sigal, specimen 73/13244: (35a) lateral view, (35b) peripheral view, Enisarai Ravine, Member 13; (36, 37) Lenticulina ambanjabensis (Esp. et Sigal): (36) specimen 77/13244: (36a) lateral view, (36b) peripheral view, Mezhgor’e settlement, Member 26; (37) specimen 78/13244, thin section close to the orthogonal one, Enisarai Ravine, below Member 1; (38) Lenticulina eichenbergi Bart. et Brand, specimen 82/13244: (38a) lateral view, (38b) peripheral view, Mezhgor’e settlement, Member 26; (39) Lenticulina neocomina Rom., specimen 74/13244: (39a) lateral view, (39b) peripheral view, Mezhgor’e settlement, Member 26; (40) Astacolus mutilatus Esp. et Sigal, specimen 84/13244, Balki settlement, Member 18; (41) Astacolus proprius K. Kuzn., specimen 85/13244, Balki settlement, Member 18; (42) Astacolus folium (Wisn.), specimen 86/13244, Balki settlement, Member 18; (43) Saracenaria latruncula (Chalilov), specimen 87/13244, Balki settlement, Member 21; (44) Saracenaria inflata Pathy, specimen 90/13244: (44a) lateral view, (44b) peripheral view, Mezhgor’e settlement, Member 26; (45) Saracenaria aculata Esp. et Sigal, specimen 89/13244: (45a) lateral view, (45b) peripheral view, Enisarai Ravine, Member 15; (46) Saracenaria compacta (Esp. et Sigal), specimen 91/13244: (46a) lateral view, (46b) peripheral view, Enisarai Ravine, Member 15; (47) Saracenaria tsarmandrosoensis Esp. et Sigal, specimen 93/13244, Mezhgor’e settlement, Member 26; (48) Saracenaria provoslavlevi Furs. et Pol., specimen 94/13244: (48a) lateral view, (48b) peripheral view, Enisarai Ravine, Member 13; (49) Pseudosaracenaria truncata Pathy, specimen 92/13244, Balki settlement, Member 21; (50) Conorboides hofkeri (Bart. et Brand), specimen 111/13244: (50a) dorsal view, (50b) ventral view, (50c) peripheral view, Mezhgor’e settlement, Member 26. STRATIGRAPHY AND GEOLOGICAL CORRELATION Vol. 23 No. 2 2015 NEW DATA ON BERRIASIAN BIOSTRATIGRAPHY, MAGNETOSTRATIGRAPHY 167 Plate II 5 4a 4b 2a 9a 1a 1b 3 2b 9b 6 8a 8b 9c 7 8c 10 1c 13b 11b 14b 12b 16 15 11a 11c 12a 12c 19 13a 18 13c 22 17a 17b 23 14a 20a 24 14c 21 20b 17c 25c 26 30a 29a 25a 25b 27a 27b 28a 28b 30b 32a 32b 29b 31a 31b 36a 34a 33a 34b 35a 50a 38b 37 35b 33b 38a 36b 39a 50b 50c 39b 44a 44b 40 41 42 43 STRATIGRAPHY AND GEOLOGICAL CORRELATION 45a Vol. 23 45b 46a 46b No. 2 2015 47 48a 48b 49 168 ARKADIEV et al. tion are represented by over 200 species of 63 genera (Fig. 5). As a whole, the identified foraminiferal assemblage is characteristic of the Textularia crimica– Belorussiella taurica Beds developed through the entire Crimean Region (Feodorova, 2004). The following six successive foraminiferal assemblages may be defined in the section under consideration on the basis of changes in the taxonomic composition and quantitative parameters (from the base upward) (Fig. 5): 1. The Everticyclammina virguliana–Retrocyclammina recta–Bramkampella arabica Assemblage (Members 1–12 and 18). This assemblage is characterized by the prevalence of lituolids (including complex) over nodosariid. The assemblage numbers 70 species of 45 genera in total. The characteristic species are abundant and diverse representatives of the genera Everticyclammina and Retrocyclammina, including Retrocyclammina ex gr. chouberti Hott, R. recta Gorb., Everticyclammina virguliana (Koechl.), and E. elongata Gorb., as well as Haplophragmium subaequale (Mjatluk), Melathrokerion spirialis Gorb., Charentia evoluta (Gorb.), Pseudocyclammina lituus (Yok.), Stomatostoecha rotunda Gorb., S. compressa Gorb., S. enisalensis Gorb., Bramkapella arabica Radm., Amijella amiji (Henson), Belorussiella taurica Gorb., Alveosepta jaccardi (Schrodt), Astacolus mulitatus Esp. et Sigal, A. inspissatus (Loeblich et Tappan), A. favoritus Gorb., Discorbis miser Gorb., Trocholina alpina (Leup.), T. elongata (Leup.), T. molesta Gorb., T. infragranulata Noth, and others. Thin sections from the lower part of the section (Member 2) yielded single specimens of Protopeneroplis ultragranulatus (Gorb.) and Pseudosiphoninella antiqua (Gorb.). The assemblage is named after species E. virguliana, R. recta, and B. arabica. The Rectocyclammina Beds transitional from the upper Tithonian to lower Berriasian, which are established on the Ai-Petri Plateau, and the Bramkapella Beds from the overlying limestone sequence (Gorbachik and Mokhamad, 1999) are characterized by a similar foraminiferal assemblage. The Bramkapella Beds are taken by the last authors to be the early Berriasian in age. It should be noted that the Everticyclammina virguliana–Retrocyclammina recta–Bramkampella arabica Assemblage is registered also in Member 18, which is located higher in the section. The assemblage from this member is characterized by the presence of many (several hundred) specimens of Melathrokerion spirialis Gorb. and species Flabellammina lidiae Gerke et Pol. and Triplasia elegans (Mjatl.), which are known from terminal Jurassic strata of the Boreal and Arctic provinces, against the background of dominant complex Lituolidae. These data combined with petromagnetic measurements may presumably indicate that Member 18 is repeated in the section, although this assumption requires additional investigations. We leave Member 18 in the general stratigraphic succession, although with the question mark. 2. The Lenticulina muensteri Assemblage (Members 13–17, 19) is notably dominated by Nodosariidae with representatives of the genera Lenticulina being particularly abundant and diverse and genera Saracenaria and Pseudonodosaria being subdominant. The assemblage is named after the characteristic species, which is present in all the examined samples. In total, the assemblage includes approximately 65 species of 22 genera with Ramulna aculeata Wright, Lenticulina nimbifera Esp. et Sigal, L. fracta Esp. et Sigal, Pseudonodosaria diversa (Hoff.), Saracenaria compacta Esp. et Sigal, and Hoeglundina ex gr. caracolla (Roemer) being dominant. The following species are also characteristic: Dorothia ex. oxycona (Reuss), D. kummi Zedler (minima), Nodosaria raristriata Chapman, Tristix acutangulus (Reuss), Lenticulina muensteri (Roemer), L. colligoni Esp. et Sigal, Astacolus proprius Kun., A. incurvatus (Reuss), Marginulina striatocostata Reuss, M. micra Tairov, Marginulinopsis sigali Bart., Bett. et Bolli, Saracenaria provoslavlevi Furs. et Pol., S. provoslavlevi Furs. et Pol. var. minima, S. aculata Esp. et Sigal, Dentalina gracilis d’Orb., D. guttinfera d’Orb., Citharinella pectinatimornata Esp. et Sigal, Trocholina micra Dulub., and others. The characteristic feature of this assemblage is alternative development of normal, dwarfish, and giant forms. 3. The Quadratina tunassica Assemblage (Member 20) is the least representative one, consisting only of approximately 30 species belonging to 23 genera. The assemblage is characterized by gigantism among simple lituolids. It is named after the index species of the Quadratina tunassica–Siphonella antiqua Zone (Drushchits and Gorbachik, 1979), which corresponds approximately to the upper part of the grandis Zone and lower part of the occitanica Zone. It is defined on the basis of the appearance of Quadratina tunassica Schokhina and Lenticulina protodecimae Dieni et Massari and the presence of single transit species such as Textularia crimica (Gorb.), T. densa Hoff., Citharinella pectinatimornata Esp. et Sigal, Citharina flexuosa (Bruck.), Tristix acutangulus (Reuss), Lenticulina colligoni Esp. et Sigal, L. muensteri (Roemer), Astacolus incurvatus (Reuss), Nodosaria paupercula Reuss, Saracenaria latruncula (Chalilov), Planularia crepidiularis Roemer, Lagena sztejnae Dieni et Massari, and Spirillina kubleri Mjatl. 4. The Triplasia emslandensis acuta Assemblage (Members 21–24 and lower part of Member 25) is distributed discretely through the section. In total, the assemblage includes over 100 species of 47 genera, among which Lenticulina representatives are dominant and species of the genera Saracenaria and Verneuilina are subdominant. It is named after the index species of the synonymous Triplasia emslandensis acuta Subzone (Kuznetsova and Gorbachik, 1985), approximately correlated with the upper part of the occitanica Zone and lower part of the boissieri Zone. The assemblage is defined on the basis of the appearance of Recurvoides ex gr. paucus Dubr., Haplophragmoides subchapmani K. Kuzn., Triplasia emslan- STRATIGRAPHY AND GEOLOGICAL CORRELATION Vol. 23 No. 2 2015 NEW DATA ON BERRIASIAN BIOSTRATIGRAPHY, MAGNETOSTRATIGRAPHY densis acuta Brat. et Brand., Pseudolamarckina reussi (Ant.), Lenticulina nuda (Reuss), L. nodosa (Reuss), and Saracenaria inflata Pathy and the presence of abundant specimens of transit species: Lenticulina macra Gorb., L. neocomina Rom., Vaginulina kochii Roemer, Saracenaria latruncula (Chalilov), Spirillina kubleri Mjatl. 5. The Lenticulina andromede Assemblage (upper part of Member 25 and lower part of Member 26) is represented by over 70 species of 40 genera with the distinctly dominant share of Lenticulina representatives. The assemblage is marked by the appearance of abundant Lenticulina andromede Esp. et Sigal, Tristix valanginica Schokhina, Lenticulina guttata guttata (Dam), L. ex gr. ouachensis Sigal, L. praegaultina Bart., Falsopalmula costata Gorb., and Istriloculina rectoangularia Mats. et Temirb. They are accompanied by species inherited from underlying sediments: abundant Ramulina aculeata Wright, Ammobaculites inconstans gracilis Bart. et Brand, Textularia crimica (Gorb.), Belorussiella taurica Gorb., Lenticulina nuda (Reuss), L. macra Gorb., L. neocomina Rom., Discorbis praelongus Gorb., Spirillina kubleri Mjatl., and others. 6. The Conorboides hofkeri Assemblage (upper part of Member 26) is named after one of the index species of the Conorbina heteromorpha–Conorboides hofkeri Zone (Drushchits and Gorbachik, 1979), correlated with the upper part of the occitanica Zone and boissieri Zone. The assemblage includes over 50 species of 30 genera being barren of distinct dominant forms. It is marked by the appearance of Dorothia kummi Zedler, Dentalina marginulinoides Reuss, Miliospirella caucasica Ant., Discorbis agalarovae Ant., Epistomina tenuicostata Bart. et Brand, E. ornata (Roemer), and Conorboides hoffkeri (Bart. et Brand), accompanied by abundant transit species Belorussiella taurica Gorb., Pseudolamarckina reussi (Ant.), Saracenaria inflata Pathy, Hoeglundina ex gr. caracolla (Roemer), and Spirillina kubleri Mjatl. and common Bulbabaculites inconstans (Bart. et Brand), Nautiloculina oolithica Mochler, Textularia crimica (Gorb.), Lenticulina macra Gorb., L. muensteri (Roemer), Astacolus ambanjabensis (Esp. et Sigal), Trocholina giganta Gorb. et Manz., and others. In central Crimea, Berriasian foraminifers were investigated by T.N. Gorbachik (Kuznetsova and Gorbachik, 1985). The comparison of our data with the results of this author is difficult since she mentions only 31 species for the entire Berriasian section of central Crimea, including taxa identified with the open nomenclature. The foraminiferal species documented in the examined sections are known from the Tithonian– Valanginian sections of Crimea, the Caucasus, the Caspian region, Syria, Germany, France, Italy, and Madagascar. Within the Tethyan region, the Everticyclammina virguliana–Retrocyclammina recta– Bramkampella arabica Assemblage of central Crimea is most similar to Berriasian foraminiferal assemblages STRATIGRAPHY AND GEOLOGICAL CORRELATION 169 of Syria, the northern Caspian region, southeastern France, and Italy. The assemblages from the middle and upper parts of Berriasian sections in central Crimea are best comparable with their counterparts from the “Cenozone D” of Madagascar (Espitalie and Sigal, 1963). Thus, the foraminiferal assemblages allow successful subdivision and correlation of sections within particular regions, while their potential in interregional correlations without ammonites is very low. Ostracods. The discovery of previously unknown parts of the Berriasian section in central Crimea in 2012 substantially widened the range and characteristics of the previously defined Costacythere khiamii–Hechticythere belbekensis Beds (Arkadiev et al., 2012). The identified ostracod remains belong to 16 families. Their assemblage includes 85 species of 33 genera in total. The core of their assemblages is represented by smoothwalled forms characterized by a wide facies and stratigraphic distribution (Cytherella) and abundant representatives of the tropical (subtropical) genus Cytherelloidea. Of interest is the presence of brackish- and freshwater genus Cypridea, which is characterized by rare specimens. Ornamented forms are mostly represented by genera of the families Protocytheridae (Protocythere, Reticyhere, Hechticythere, Costacythere) and Cytheruridae (Eucytherura) (Plate III). The taxonomic and quantitative analyses of ostracod assemblages allow two biostratigraphic units of the beds rank to be defined in the examined Berriasian section (Fig. 6). The lower part of the section conditionally correlated with the ammonite occitanica Zone contains 45 ostracod species belonging to 24 genera. It is united into the Costacythere khiamii–Hechticythere belbekensis Beds on the basis of the co-occurrence of characteristic species and high abundance of Costacythere khiamii specimens. The ostracod assemblage from the upper part of the section corresponding to the part of the ammonite boissieri Zone numbers 71 species of 28 genera. It is characterized by the dominant role of the genera Cytherella, Cytherelloidea, Paracypris, Costacythere, and Reticythere. Many species are inherited from underlying sediments (36 species of 20 genera in common), while others appear at this level for the first time (35 species of 22 genera). This part of the section is attributed to the Costacythere drushchitzi–Reticythere marfenini Beds on the basis of high abundance and joint occurrence of these characteristic species. The ostracod species registered in the examined section are mostly known from Lower Cretaceous (Berriasian–Hauterivian) deposits of Crimea (Neale, 1966; Tesakova and Rachenskaya, 1996a, 1996b), the North Caucasus (Kolpenskaya, 2000), Central Asia (Andreev, 1986), England (Neale, 1962, 1967, 1978; Slipper, 2009), France (Atlas…, 1985; Donze, 1964, 1965; etc.), Germany (Triebel, 1938; Gründel, 1964; etc.), and Poland (Kubiatowicz, 1983). Acrocythere diversa Donze and Bythoceratina variabilis Donze are first described from Berriasian strata of France (Donze, Vol. 23 No. 2 2015 STRATIGRAPHY AND GEOLOGICAL CORRELATION Stage Zone Vol. 23 No. 2 2015 Berriasian jacobi boissieri Subzone, beds with fauna (Arkadiev et al., 2012) Beds with Zeillerina baksanensis ? Beds with Symphythiris arguinensis Riasanites crassicostatum Neocosmoceras euthymi Beds with Malbosiceras chaperi ? grandis Dalmasiceras tauricum occitanica Textularia crimica–Belorussiella taurica Lenticulina Conorandromede boi des hofkeri Foraminiferal beds/ assemblages ? Triplasia emslandensis acuta Kuchki Bechku 28 30 27 15 26 30 25 15 24 7.6 23 8.4 22 5.5 21 18 20 8 17 0.3 19 10 18 5 16 1.65 15 3.6 14 1.5 13 2 11–12 1 10 2.8 9 11.5 7 7–8 6 6 5 4 2.7 3 63 2 12 50 1 4.5 Formation, sequence Member Thickness, m Lithology 1 2 3 4 5 6 7 8 9 1011121314151617181920212223242526272829303132333435363738394041424344 45464748 49 50 51 525354 5556 57585960616263646566676869707172 73 74757677 787980 81 82 83 84 4 6 8 1314 23242526 2122 20 1516171819 121314 21 24 293031 33 394041 394041 424344 4546 4748 49 50 51 52 53545556 57585960616263646566676869707172 73 74757677 7879 80 81 82 83 84 ARKADIEV et al. 272829303132333435363738 Gaps in sampling, m Stomatostoecha enisalensis Trocholina elongata Trocholina alpina Bramkampella arabica Ammobaculites inconstans gracilis Melathrokerion spirialisilis Bulbabaculites inconstans Rectocyclammina recta Pseudocyclammina sp. (cf. P. lituus) Moechlerina basilinensis Belorussiella taurica Charentia evoluta Everticyclammina virguliana Rectocyclammina ex gr. chouberti Nautiloculina oolithica Protopeneroplis ultragranulatus Pseudosiphoninella antiqua Feurltillia frequens Planularia madagascariensis Trocholina molesta Amijiella amiji Trocholina giganta Astacolus ambanjabensis Pseudocyclammina spharoidalis Trocholina burlini Astacolus hamililis Astacolus favoritus Astacolus inspissatus Triplasia minima sp. nov. Stomatostoecha rotunda Haplophragmium subaequale Everticyclammina elongata Astacotys mutilatus Discorbis infracretaceus Astacolus calliopsis Dentalina nana Lenticulina macra Lenticulina neocomina Lenticulina ex gr. subalata Lenticulina sp. 2 (Gorb., 1978) Stomatostoecha compressa Discorbis miser Astacolus ex gr. proprius Lenticulina aff. andromede minima Discorbis crimicus Lenticulina aff. akmetchetica Trocholina infragranulata Triplasia elegans Flabellammina lidiae Alveosepta jaccardi Lenticulina sp. 1 (Gorb., 1978) Lenticulina muensteri Marginulina striatocostata Saracenaria provoslavlevi Dorothia ex gr. oxycona Ramulina aculeata Vaginulina sp. 2385 E et S? 1963 Marginulinopsis sigali Nodosaria raristriata Saracenaria aculata Lenticulina aff. ambanjabensis Lenticulina aff. uspenskajae (minima) Lenticulina fracta Saracenaria provoslavlevi minima Astacolus proprius Pseudonodosaria diversa Dentalina communis Pseudonodosaria mutabilis Saracenaria tsaramandrosoensis Frondicularia complexa Saracenaria compacta Lenticulina colligoni–protodecimae Vaginulina kochii Planularia crepidularis Tristix acutangulus Citharina flexuosa Planktonic forms Saracenaria latruncula Spirillina kubleri Dorothia kummi (minima) Tristix acutangulus micrus Trocholina micra Lenticulina ex gr. nimbifera Discorbis praelongus 170 22 17 4 15 9 15 5.6 2 45 65 8 9 1011 10 50– 60 1 2 3 4 5 6 7 Fig. 5. Stratigraphic distribution of main foraminiferal species in Berriasian sections of central Crimea. For legend, see Fig. 4. 6.25 Lenticulina muensteri Quadratina tunassica Evirticyclammina virguliana, Rectocyclammina recta, Bramkampella arabica Bedenekyr STRATIGRAPHY AND GEOLOGICAL CORRELATION Stage Zone Vol. 23 No. 2 2015 Berriasian jacobi occitanica boissieri Subzone, beds with fauna (Arkadiev et al., 2012) Beds with Zeillerina baksanensis ? Beds with Symphythiris arguinensis Riasanites crassicostatum Neocosmoceras euthymi Dalmasiceras tauricum Beds with Malbosiceras chaperi ? grandis Textularia crimica–Belorussiella taurica Foraminiferal beds/ assemblages ? Lenticulina Conorandromede boides hofkeri Kuchki Triplasia emslandensis acuta Bechku 28 30 27 15 26 30 25 15 24 7.6 23 8.4 22 5.5 21 18 19 10 11.5 20 8 9 18 5 17 0.3 16 1.65 15 3.6 14 1.5 13 2 1 10 2.8 11–12 2.7 7 6 6 7–8 5 4 3 63 50 4.5 2 12 1 6.25 Lenticulina muensteri Quadratina tunassica Evirticyclammina virguliana, Rectocyclammina recta, Bramkampella arabica Bedenekyr Formation, sequence Member Thickness, m Lithology 22 17 4 15 9 15 5.6 2 45 65 10 50– 60 123 119120121122 106107108109110111112113114115116117118 98 99 100 101102103104105 90 91 92 93 94 95 96 97 128 125126127 124 130131132 129 133 138 139140141142 135 136 137 134 Abundance of species: 1–10 specimens in sample 10–50 specimens in sample over 100 specimens in sample Occurrence of species: permanent discrete 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136 137138139140141142 85 86 87 88 89 Fig. 5. (Contd.) Gaps in sampling, m Dentalina gracilis Dentalina guttinfera Marginulina micra Citharinella pectinatimornata Hoglundina ex gr. caracolla Globulina fusica Lenticulina colligoni Astacolus incurvatus Globulina prisca Astacolus laudatus Frondicularia caspidiata Tristix crassa Pseudosaracenaria truncata Quadratina tunassica Lenticulina protodecimae Lagena sztejnae Astacolus sp. 1 Nodosaria sceptium Textularia densa Nodosaria paupercula Textularia crimica Verneuilina angularis Citharina rodocostata Rhizammina individa Lenticulina singulare Astacolus planiusculus Saracenaria valanginiana Planularia aff. plana Discorbis agalarovae Textularia notha Marssonella pseudocostata Saracenaria inflata Pseudolamarkina reussi Lamarckina (?) asteriaformis Recurvoides ex gr. paucus Haplophragmoides subchapmani Lenticulina nodosa Triplasia emslandensis acuta Lenticulina sp. 3 f Lenticulina nuda Tristix insignus Lenticulina guttata guttata Istriloculina rectoangularia Lenticulina andromede Lenticulina ex gr. ouachensis (cf. L. o. inchoata) Tristix valanginica Lenticulina praegaultina Falsopalmula costata Istriloculina fabaria Conorboides hofkeri Dentalina pseudodebilis Tristix acutangulus Miliospirella caucasica Epistomina ornata Dentalina marginuloides Discorbis agalarovae Dorothia kummi Epistomina tenuicostata NEW DATA ON BERRIASIAN BIOSTRATIGRAPHY, MAGNETOSTRATIGRAPHY 171 172 ARKADIEV et al. 1964). Metacytheropteron sp. A Pok., Quasigermanites bicarinatus moravicus Pok., Eucytherura trinodosa Pok., and two close species Eucytherura ex gr. trinodosa Pok. and Eucytherura aff. soror Pok. are identified in Tithonian sections of the Czech Republic (Pokorny, 1973). Of these species, E. trinodosa, E. ex gr. trinodosa, and E. aff. soror were found in the upper Tithonian–lower Berriasian section of eastern Crimea (Arkadiev et al., 2012). The subspecies Quasigermanites bicarinatus moravicus Pok. was previously recorded in the upper part of the Berriasian section of eastern Crimea, while the close species Quasigermanites aff. bicarinatus Pok. was documented in the middle part of the Berriasian section in southwestern Crimea. Neocythere dispar Donze was first described from the basal part of the Valanginian Stage in the stratotype region of the Berriasian Stage (Donze, 1965) and subsequently registered in Berriasian layers of Mangyshlak (Andreev and Oertli, 1970). We found this species in the upper and middle–upper parts of the Berriasian section in the central and western parts of the Crimean Peninsula, respectively. Many ostracod species were first described from the Berriasian section of central Crimea: Cytherella krimensis Neale, C. lubimovae Neale, Cytherelloidea flexuosa Neale, C. mandelstami Neale, Bairdia menneri Tes. et Rach., B. kuznetsovae Tes. et Rach., Cypridea funduklensis Tes. et Rach., Pontocyprella nova Neale, Pontocypris cuneata Neale, Neocythere pyrena Tes. et Rach., Costacythere khiamii Tes. et Rach., C. drushchitzi (Neale), C. andreevi Tes. et Rach., C. foveata Tes. et Rach., Hechticythere belbekensis Tes. et Rach., Reticythere marfenini (Tes. et Rach.), Eocytheropteron sp. A Neale (Neale, 1966; Tesakova and Rachenskaya, 1996a, 1996b). The defined ostracod assemblages of central Crimea exhibit the most similarity to their assemblage from the Berriasian stratotype (13 genera and 2 species in common) (Grekoff and Magne, 1966; Neale, 1967). The similarity at the species level is noted to the Berriasian assemblage from the section cropping out along the Urukh River in the North Caucasus (10 genera and 7 species in common) (Kolpenskaya, 2000). Nevertheless, a reliable correlation between ostracod beds defined in central Crimea and coeval stratigraphic units in the Urukh section is impossible. The assemblage of the Costacythere khiamii– Hechticythere belbekensis Beds is comparable with the similar Berriasian assemblage from the Berriasian tauricum Subzone defined in southwestern Crimea (Bel’bek River basin) (Arkadiev et al., 2012). It should be noted that the ostracod assemblage from the upper part of Section 2952 (Sample 49-9-1) is similar in its taxonomic composition and abundance of Cytherella lubimovae, Costacythere khiamii, and C. foveata to the assemblage from Section 2949 (Sample 39-2-1). Palynomorphs. In total, 28 samples were subjected to the palynological analysis. The samples were treated in accordance with the traditional technique used in palynological investigations, which is based on the hydrofluoric method and modified technology (Raevskaya and Shurekova, 2011). No palynomorphs are observed in 12 samples. Other samples contain variable quantities of spores, pollen, and microphytoplankton represented by wellpreserved cysts of dinoflagellates, prasinophytes, and acritarchs (Plate IV). The proportions of palynomorphs in different parts of the section are variable. In the lower part of the ammonite Dalmasiceras tauricum Subzone, the palynomorph assemblage is represented by Classopollis pollen (47%), spores and bisaccate coniferous pollen (1%), and marine microphytoplankton (52%). In the remaining part of the section, Classopollis pollen constitutes up to 90% and spores + bisaccate coniferous pollen are 1–5%. The share of microphytoplankton varies from 15% in the Malbosiceras chaperi Beds to Plate III. Ostracods from Berriasian sediments of central Crimea. (1) Cytherella krimensis Neale, specimen 2/13244, left valve, lateral view, Balki settlement, occitanica Zone; (2) Cytherella lubimovae Neale, specimen 176/13220, left valve, lateral view, Balki settlement, boissieri Zone, Symphythris arguinensis Beds; (3) Paracypris felix (Neale), specimen 3/13244, left lateral view, Balki settlement, occitanica Zone; (4) Cytherelloidea flexuosa Neale, specimen 4/13244, left valve, lateral view, Balki settlement, occitanica Zone; (5) Cytherelloidea mandelstami Neale, specimen 5/13244, left valve, lateral view, Balki settlement, occitanica Zone; (6) Eucytherura ex gr. trinodosa Pokorny, specimen 6/13244, left valve, lateral view, Balki settlement, occitanica Zone; (7) Eucytherura sp. 1, specimen 7/13244, right valve, lateral view, Balki settlement, occitanica Zone; (8) Eucytherura sp., specimen 8/13244, left valve, lateral view, Balki settlement, occitanica Zone; (9) Paranotacythere sp., specimen 9/13244, left valve, lateral view, Balki settlement, occitanica Zone; (10) Eocytheroteron sp., specimen 10/13244, left valve, lateral view, Balki settlement, occitanica Zone; (11) ?Furbergiella sp., specimen 11/13244, left valve, lateral view, Balki settlement, occitanica Zone; (12) Neocythere pyrena Tes. et Rach., specimen 212/13220, left valve, lateral view, Balki settlement, bossieri Zone, euthymi Subzone; (13) Costacythere drushchitzi (Neale), specimen 230/13220, right valve, lateral view, male, Mezhgor’e settlement, bossieri Zone; (14) Costacythere drushchitzi (Neale), specimen 12/13244, right lateral view, Balki settlement, occitanica Zone; (15) Reticythere marfenini Tes. et Rach., specimen 13/13244, left lateral view, male, Balki settlement, bossieri Zone, euthymi Subzone; (16–18) Costacythere khiami Tes. et Rach.: (16) specimen 14/13244; (17) specimen 15/13244, left lateral views; (18) specimen 16/13244, right valve, lateral view, females, Balki settlement, occitanica Zone; (19, 20) Costacythere foveata Tes. et Rach.: (19) specimen 17/13244, left valve, lateral view, female; (20) specimen 18/13244, left valve, lateral view, male, Balki settlement, occitanica Zone; (21) Costacythere andreevi Tes. et Rach., specimen 19.13244, left valve, lateral view, Balki settlement, occitanica Zone; (22) Hechticythere belbekensis Tes. et Rach., specimen 20.13244, right valve, lateral view, Balki settlement, occitanica Zone, tauricum Subzone; (23) Cythereis sp. B, specimen 21/13244, right valve, lateral view, Balki settlement, occitanica Zone; (24) Schuleridea ex gr. juddi Neale, specimen 22/13244, right lateral view, Balki settlement, occitanica Zone. STRATIGRAPHY AND GEOLOGICAL CORRELATION Vol. 23 No. 2 2015 NEW DATA ON BERRIASIAN BIOSTRATIGRAPHY, MAGNETOSTRATIGRAPHY 173 Plate III 1 2 100 µm 100 µm 100 µm 5 7 30 µm 14 16 15 100 µm 100 µm 12 50 µm 13 17 50 µm 11 50 µm 100 µm 8 100 µm 10 9 100 µm 100 µm 100 µm 6 50 µm 100 µm 4 3 100 µm 100 µm 19 18 20 100 µm 100 µm 21 100 µm 100 µm 22 STRATIGRAPHY AND GEOLOGICAL CORRELATION 23 100 µm Vol. 23 No. 2 24 100 µm 2015 174 ARKADIEV et al. 5% in the upper part of the ammonite tauricum Subzone and boissieri Zone. Through the entire section (Fig. 7), spores are represented by smooth grains of Leiotriletes spp., Cyathidites sp., and Schizaleales ferns with the costate (Cicatricososporites sp.), grumous (Verrucosisporites sp.), and foveate (Klukisporites variegatus Coup.) exine. The sediments of the Dalmasiceras tauricum Subzone and boissieri Zone are marked by the appearance of Pteropsida spores Eboracia torosa (Sach. et Iljina), Concavissimisporites punctatus (Delcourt et Sprumont), Kraeuselisporites sp., and Microlepidites crassirimosus Timosch. and spores of Gleicheniaceae and Lycopodiaceae ferns (Lycopodiumsporites sp., Densiosporites velatus Weyland et Krieger). The pollen spectrum includes grains of Classopollis spp., Piceapollenites spp., Pinuspollenites spp., Callialasporites dampieri (Balme), and Quadraeculina anellaeformis Mal. The Phoberocysta neocomica dinocyst assemblage defined in the interval of the Berriasian section most saturated with marine phytoplankton remains (lower part of the ammonite Dalmasiceras tauricum Subzone) is represented by the following groups: (1) chorate and proximoshorate cysts of dinoflagellates: Hystrichosphaerina? orbifera (Klement), Systematophora areolata Klement, Kleithriasphaeridium eoinodes (Eisenack), Tanyosphaeridium isocalamum (Deflandre et Cookson), Dichadogonyaulax? pannea (Norris), Dichadogonyaulax culmula (Norris), Achomosphaera sp., Cleistosphaeridium varispinosum (Sarjent), Ctenidodinium sp., Epiplosphaera reticulospinosa Klement, Bourkidinium sp., Sentusidinium spp.; (2) cavate cysts of dinoflagellates: Scriniodinium campanula Gocht, Gonyaulacysta sp., Phoberocysta neocomica (Gocht); (3) proximate cysts of dinoflagellates: Pseudoceratium cf. pelliferum Gocht, Apteodinium sp., Rhynchodiniopsis martonensis Bailey et al., Rh. cladophora (Deflandre), Cribroperidinium sp., Nannoceratopsis deflandrei Evitt subsp. deflandrei, Durotrigia sp.; (4) prasinophytes of the genus Pterospermella; (5) acritarchs Micrhystridium sp. In the upper part of the ammonite Dalmasiceras tauricum Subzone and in the boissieri Zone, microphytoplankton is represented by cysts of the dinoflagellate species Systematophora areolata Klement, Epiplosphaera spp., Kleithriasphaeridium eoinodes (Eisenack), Phoberocysta neocomica (Gocht), Rhynchodiniopsis cladophora (Deflandre), Durotrigia sp., and Oligosphaeridium patulum Riding et Thomas; prasinophytes belonging to the genus Pterospermella; and diverse acritarchs. Despite the scarcity of the taxonomic composition of microphytoplankton remains in this interval of the section, it contains species characteristic of the above-mentioned Phoberocysta neocomica dinocyst assemblage from the lower part of the Dalmasiceras tauricum Subzone. The impoverishment of the assemblage is most likely explained by changes in depositional environments. The Phoberocysta neocomica Beds established in central Crimea are also recognizable in southwestern and eastern parts of the peninsula (Arkadiev et al., 2012). The dinocyst assemblage from this unit is correlated with the assemblage from the Berriasian Dichadogonyaulax bensoni dinocyst zone of France (Monteil, 1992), upper Riazanian–lower Valanginian Pheoberocysta neocomica Zone of northwestern Europe (Fisher and Riley, 1980), and synonymous dinocyst zone of eastern Canada (Williams, 1975). The microphytoplankton assemblage documented in the Malbosiceras chaperi Beds and underlying strata (Sections 2949, 2948) includes the following groups: proximate cysts of dinoflagelaltes species Batiacasphaera sp., Cribroperidinium sp., Muderongia simplex Alberti, and Muderongia Complex; chorate and proximate cysts Kleithriasphaeridium eoinodes (Eisenack), Cometodinium habibi Montail, Systematophora areolata Klement, Prolixosphaeridium parvispinum (Deflandre), Prolixosphaeridium spp., Achomosphaera sp., Spiniferites ex gr. ramosus (Ehrenberg); prasinophytes Pterospermella. As a whole, the dinocyst assemblage in Berrasian sediments of central Crimea is characterized by an impoverished composition. Nevertheless, it is evident that by its taxonomic composition this assemblage is close to that from the Phoberocysta neocomica Beds. DEPOSITIONAL ENVIRONMENTS The depositional environments of Berriasian sediments were relatively diverse, although as a whole they Plate IV. Dinocysts from Berriasian sediments of central Crimea. All the specimens originate from Berriasian section 2940 near the Balki settlement in central Crimea. (Figs. 1–5, 8, 10–14, 17–23) occitanica Zone, tauricum Subzone, Member 20, Sample 149/13220; (figs. 6, 7, 9) occitanica Zone, tauricum Subzone, Member 21, Sample 147/13220; (figs. 15, 16) bossieri Zone, Symphythiris arguinensis Beds, Member 25, Sample 148/13220. (1a, 1b) Phoberocysta neocomica (Gocht); (2) Achomosphaera sp.; (3) Tanyosphaeridium isocalamum (Defl. et Cook.); (4, 5) Hystrichsphaerina? orbifera (Klement); (6) Oligosphaeridium patulum Riding et Thomas; (7) Epiplosphaera gochti (Fens.); (8) Cleistosphaeridium varispinosum (Sarjent); (9) Epiplosphaera ?areolata (Klement); (10) Kleithriasphaeridium eoinodes (Eisen); (11) Circulodinium distinctum (Defl. et Cook.); (12) Circulodinium brevispinosum (Pocock); (13) Dichadogonyaulax culmula (Norris); (14) Scrinodinium campanula Gocht; (15, 16) Systematophora sp.; (17) Apteodinium sp.; (18) Ctenidodinium sp.; (19) Dichadogonyaulax? pannea (Norris); (20) Nannoceratopsis deflandrei Evitt subsp. deflandrei; (21) Tanyosphaeridium sp.; (22) Micrhystridium sp.; (23) Pterospermella sp. STRATIGRAPHY AND GEOLOGICAL CORRELATION Vol. 23 No. 2 2015 NEW DATA ON BERRIASIAN BIOSTRATIGRAPHY, MAGNETOSTRATIGRAPHY 175 Plate IV 1a 1b 2 3 5 6 4 8 9 10 7 13 11 12 14 15 16 17 18 23 19 20 STRATIGRAPHY AND GEOLOGICAL CORRELATION 21 Vol. 23 22 No. 2 2015 50 µm STRATIGRAPHY AND GEOLOGICAL CORRELATION Vol. 23 No. 2 e r r i a s i a boissieri Costacythere drushchitzi– Reticythere marfenini Bechku Subzone, beds with fauna (Arkadiev et al., 2012) Beds with Zeillerina baksanensis Beds with Symphythiris arguinensis Bedenekyr Riasanites crassicostatum Neocosmoceras euthymi Dalmasiceras tauricum Beds with Malbosiceras chaperi grandis Costacythere khiamii– Hechticythere belbekensis Ostracod beds Kuchki 28 30 27 15 26 30 25 15 24 7.6 23 8.4 22 5.5 21 18 19 10 18 5 20 8 17 0.3 16 1.65 15 3.6 14 1.5 13 2 11–12 1 10 2.8 9 11.5 7 6 6 7–8 5 4 2.7 3 63 2 12 50 1 4.5 6.25 Stage Zone n Formation, sequence Member Thickness, m 22 17 4 15 9 15 5.6 2 45 Gaps in sampling, m 12 7 Cytherelloidea mandelstami 2 1 4 2? 4j 3? Paracypris sp. Patellacythere sp. Costacythere drushchitzi 2 34 1 4 2 9 2 2 3 13 7 39 1 7 2 13 3 2 2 10 2 2 3 7 5 5 6 10 15 9 3 6 35 1 142 7 2 8 14 10 3 39 7 39 15 6 13 14 1 2 30 3 40 7 25 2 3 6 16 2 5 3 1 4 2 6 1 1 1 13 1 12 1 12 2 3 10 10 9 2 78 37 1 7 10 121 10 1 8 2 11 1 62 4 2 16 15 1 2 1 1 22 10 1 2 1 1 1 1 15 2 2 5 3 10 15 7 7 93 103 77 26 8 6 986 262 5 5 1 1 1 1 1 71 1 1 1 5 1 123 16 2 3 72 15 57 3 2 5 2 4 4 1 6 14 1 30 149 27 1 6 39 32 13 1 2 163 82 340 15? 1 33 2 70 1009 4? 2 Costacythere andreevi Bythoceratina sp. Costacythere foveata Costacythere khiamii Hechticythere belbekensis ?Fuhrbergiella sp. Paranotacythere sp. Cythereis sp. B Schuleridea ex gr. juddi Quasihermanites bicarinatus moravicus Pontocyprella sp. “Cypridea” sp. Costacythere sp. Reticythere marfenini 50 7 7 36 23 50 242 12 52 330 14 13 55 5 220 83 1565 267 3 1 1 260 76 230 11 93 24 3 226 46 4 40 57 1 1 2 23 1 30 24 353 Cytherella lubimovae Cytherella krimensis Cytherella fragilis Cytherella sp. 2 6 11 1 1 131 Protocythere sp. 1 Bairdia sp. Schuleridea aff. juddi 2 1 8 1 3 Eucytherura aff. trinodosa 2 1 2 Eocytheropteron sp. 7 4 1 39 1 21 3 40 1 1 1 8 40 21 13 8 1 15 1 16 12 4 1 81 13 13 1 1 Cytherelloidea flexuosa Neocythere sp. Pontocypris felix 5 Cythereis aff. senckenbergi Paracypris aff. caerulea Acrocythere alexandrae Schuleridea? sp. indet. 2 1 2 4 2 1 8 1 1 3 1 3 2 14 1 1 3 Eucytherura sp. 2 Paracypris aff. parallela Acrocythere aff. hauteriviana Pontocyprella nova 15 1 6 6 1 2 1 1 2 3 5 Cypridea funduklensis Eucytherura aff. soror Cytherelloidea sp. 9 3 1 1 3 2 1 36 1 42 17 7 1 9 1 1 1 2 14 1 2 10 1 5 11 15 7 1 4 1 1 2 Ostracods 8 2 5 12 1 Eucytherura sp. 1 Metacytheropteron sp. A Bythoceratina ex gr. variabilis 2 4 3 1 Neocythere pyrena Pontocyprella elongata Pontocypris cuneata Pontocyprella aff. superba Macrocypris sp. Pontocyprella aff. nova Pontocyprella sp. (aff. P. harrisiana) Paracypris sp. (P. ex gr. elegans) Neocythere dispar Pterygocythere? sp. Eucytherura aff. ardescae Bairdia menneri 1 1 1 1 1 4 6 3 3 10 2 6 3 2 21 7 3 1 1 3 15 10 1 3 11 1 31 3 22 4 1 3 1 ARKADIEV et al. 65 10 50– 60 Fig. 6. Stratigraphic distribution of main ostracod species in Berriasian sections of central Crimea. For legend, see Fig. 4. Lithology Acrocythere aff. alexandrae Bairdia kuznetsovae Eocytheropteron sp. A. Acrocythere diversa Eucytherura ardescae Eucytherura paula Paranotacythere diglypta Vocontiana sp. Eucytherura trinodosa Bythocypris sp. (B. arcuta) 176 2015 B occitanica jacobi STRATIGRAPHY AND GEOLOGICAL CORRELATION Stage Zone Vol. 23 No. 2 2015 Berriasian occitanica jacobi boissieri Subzone, beds with fauna Beds with Zeillerina baksanensis Beds with Symphythiris arguinensis Riasanites crassicostatum Neocosmoceras euthymi Dalmasiceras tauricum Beds with Malbosiceras chaperi grandis Phoberocysta neocomica Bedenekyr Kuchki 28 30 27 15 26 30 25 15 24 7.6 23 8.4 22 5.5 21 18 20 8 17 0.3 19 4 18 5 16 1.65 15 3.6 14 1.5 13 2 1 11–12 10 2.8 9 11.5 6 6 6.25 7–8 7 5 4 2.7 3 63 2 12 1 4.5 50 Dinocysts beds Bechku Formation, sequenc Member Thickness, m 22 17 4 15 9 15 1 2 45 65 10 50– 60 Gaps in sampling, m 31-12-1 31-8-1 31-7-1 31-5-1 Sample number Cicatricosisporites sp. Klukisporites variegatus Cyathidites spp. Verrucosispontes sp. Leiotriletes spp. Microlepidites crassirimosus Concavissimisporites punctatus Gleicheniidites sp. Contignisporites sp. Eboracia torosa Densoisporites velatus Disaccites gen. gen. spp. Classopollis spp. Pollen Callialasporites dampieri Quadraeculina anellaeformis Spores Lycopodiumsporites sp. 31-3-1 31-2-1 31-1-1 27-1-3 27-1-2 27-1-1 25-11-2 25-11-1 25-9-2 25-9-1 25-7-1 25-3-1 25-2-1 25-1-1 26-1-1 29-1-3 29-1-2 29-1-1 41-9-1 41-7-2 41-7-1 41-5-2 41-5-1 41-3-2 41-3-1 38-4 38-238-3 38-1-2 38-1-1 39-3-1 39-2-1 Kraeuselisporites sp. Proximate cyst gen. et sp. indet. Muderongia Complex <1% 1–10% >50% Chorate cyst gen. et sp. indet. Systematophora areolata Kleithriasphaeridium eoinodes Prolixosphaeridium parvispinum Batiacasphaera sp. Cribroperidinium sp. Achomosphaera sp. Cometodinium habibii Spiniferites ex gr. ramosus Phoberocysta neocomica Rhynchodiniopsis cladophora Durotrigia sp. Sentusidinium spp. Circulodinium distinctum Ctenidodinium sp. Systematophora sp. Gonyaulacysta sp. Hystrichosphaerina? orbifera Nannoceratopsis deflandrei subsp. deflandrei Psendoceratium cf. pelliferum Apteodinium sp. Scriniodinium campanula Tanyosphaeridium isocalamum Rhynchodiniopsis martonensis Epiplosphaera reticulospinosa Dichadogonyaulax? pannea Dichadogonyaulax culmula Circulodinium brevispinosum Cleistosphaeridium varispinosum Epiplosphaera ? areolata Oligosphaeridium patulum Epiplosphaera gochtii Phallocysta elongata Tubotuberella sp. Muderongia sp. Batioladinium jaegeri Leptodinium sp. Dichadogonyaulax sellwoodii Dinocysts Proportions of palynomorphs in palynological spectra: Fig. 7. Stratigraphic distribution of palynomorphs in Berriasian sections of central Crimea. For legend, see Fig. 4. Lithology Pterospermella spp. Prasinophytes Micrhystridium spp. Acritarchs NEW DATA ON BERRIASIAN BIOSTRATIGRAPHY, MAGNETOSTRATIGRAPHY 177 178 ARKADIEV et al. were always associated with development of the carbonate platform. The lower part of the section (Members 1–18) demonstrates a relatively uniform composition of calcareous sediments in both the lateral and the vertical direction. The presence of clay and marlstone intercalations and the absence of features indicating extremely shallow areas, landslides, and accumulation of detrital sediments imply the formation of this part of the section in settings of an almost flat homoclinal ramp. The examined limestone varieties belong to two ramp microfacies (RMF; Flügel, 2010): (1) RMF 3 (Members 1–4, 18) is represented by wacke- and packstones with skeletal detritus bioturbated by crustaceans (Thalassinoides, Plate V, fig. 1). The presence of micrite, skeletal detritus, and ooids indicates calm to moderate hydrodynamics. This microfacies is characteristic of the middle and/or outer ramp. (2) RMF 9 (Members 8, 9, 14, 16) comprises pack-, wacke-, and floatstones with bioclasts and intraclasts of the ramp, rare thalassinoid burrows, and lenses of shelly floatstones (SMF 8 after Flügel, 2010). This microfacies characterizes the middle and/or outer ramp and calm to moderate hydrodynamics. Skeletal detritus in both microfacies represents typical material redeposited from inner parts of the ramp. The rare sandstone intercalations (Members 11, 12, Plate V, figs. 5, 6) with well-developed trough to horizontal bedding locally disturbed by crustacean Ophiomorpha burrows (Plate V, fig. 5) were probably deposited in tidal channels (Baraboshkin, 2011). The effect of high-energy currents is evident from the presence of oyster accumulations with separated valves (Plate V, fig. 3). Clays and marlstones (Members 5, 6, 10, 13, 15, 17, partly 18) were deposited in inner areas of the basin and/or in depressions; in either case, they indicate deeper sedimentation settings as compared with depositional environments of limestones. Corals of the genus Montlivaltia occur frequently in pelitic rocks (Wright and Burgess, 2005); therefore, their co-occurrence with belemnites and ammonites in Member 15 implies their autocthonous nature. At the same time, it is conceivable that accumulation of some clay members as well as the entire terrigenous part of the section was stimulated by climate humidization, which explains the presence of carbonaceous detritus, sand admixture, and coquinas. Thus, the lower calcareous part of the section (Members 1–4) was accumulated in environments of the middle and/or outer ramp, while its overlying part dominated by clays and marlstones was deposited in deeper settings of inner areas of the basin or under climate humidization. Taking into consideration the insignificant lateral variability of sediments in outer parts of the ramp (Tucker and Wright, 1990; Flügel, 2010) and low probability of the replacement by carbonate facies, the vertical replacement of limestone by clays resulted from transgressive processes or climate humidizatiuon. The basin deepening is consistent with the transgressive part of the megacycle in other regions corresponding to the jacobi and occitanica phases (Ogg and Hinnov, 2012). The overlying part of the section (Members 19–24) is largely represented by the terrigenous succession. Its basal layers are composed of bioturbated glauconite– quartz carbonate sandstones grading up the section into clays with abundant small pyritized shells of ammonites and other faunal remains. This trend most likely reflects the basin deepening stage. The appearance of the sponge horizon (Member 25) reflects the change in the basin dynamics. The absence of features indicating the dynamic influence of water and the presence of a significant mud component in sediments indicate that the sponge horizon was formed at depths exceeding 50 m. The growth of Spongia bioherms proceeds usually under the influence of high-energy bottom currents, which transport food particles and nutrients. Such bioherms grow near the slope bends; it is conceivable that, this area corresponded to the middle–lower ramp transition or was slightly deeper. The overlying section (Members 26–28) demonstrates a well-expressed shoaling trend, which is also consistent with the transgressive–regressive megacycle of the boissieri phase (Ogg and Hinnov, 2012). The regressive features are already evident in the upper part of Member 25 (Plate V, fig. 7), which was formed in relatively shallow environments of the warm basin. However, the substantial share of silty–sandy terrigenous admixture prevented accumulation of pure carbonate sediments in this zone. At the same time, the presence of Ophiomorpha burrows implies an unconsolidated mobile substrate. The higher carbonate content in Members 26–27 and the presence of abundant remains of diverse normal-marine organisms, including oysters, brachiopods, and echinoderms, indicate open basin (ramp?) settings with the dominant role of tidal currents. The section is crowned by Member 28, represented by coral–rudist–algae limestones Plate V. Fragments of the section structure and some ichnofossils in Berriasian sediment. (1) Thalassinoides suevicus (Rieth) burrow, Member 3; (2) Gyrolithes sp. burrow, presumably Members 10–12; (3) accumulation of oyster Pycnodonte weberae Yanin shells, Member 12; (4) limestones entirely bioturbated by Thalassinoides burrows, Member 2; (5) horizontally bedded sandstones with Ophiomorpha sp. (arrow), Member 12; (6) trough cross bedding in sandstones, some layers are enriched with bioclasts, Member 12; (7) outcrops of Member 25 near the Pasechnoe settlement; (8) outcrops of Member 28 (biohermal limestones) in the quarry of the Pasechnoe settlement, the top of the quarry wall corresponds to the presumable Berriasian– Valanginian boundary. (Figs. 1–6) Balki settlement area, photo by V.K. Piskunov, 2012; (figs. 7, 8) photo by E.Yu. Baraboshkin, 2002. STRATIGRAPHY AND GEOLOGICAL CORRELATION Vol. 23 No. 2 2015 NEW DATA ON BERRIASIAN BIOSTRATIGRAPHY, MAGNETOSTRATIGRAPHY 179 Plate V 1 2 3 4 5 6 7 8 STRATIGRAPHY AND GEOLOGICAL CORRELATION Vol. 23 No. 2 2015 180 ARKADIEV et al. (Plate V, fig. 8), which were deposited on the coastal shoal raised intermittently above the sea level. The Berriassian sedimentation stage terminates with desiccation of the carbonate platform, which was accompanied by karst processes and reorganization of the sedimentary system: in the Valanginian, terrigenous sedimentation became prevalent. Most identified ostracod taxa are characteristic of basins with normal salinity. Single representatives of their genera able to resist salinity variations or dwell in brackish-water to fresh-water environments do not effect on in their general distribution (Morkhoven, 1963; Prakticheskoe…, 1999 ). The results of the paleoecological analysis of ostracod assemblages are also consistent with presumable basin deepening (Members 5–18) and shoaling (Member 26) and confirm the conclusion on deposition of the sponge horizon (Member 25) at depths exceeding 50 m. The palynological data (Fig. 7), including abundant Classopollis spp. pollen (up to 90% in spectra) produced by Cheirolepidaceae plants and dominant role of chorate dinocysts with long processes, imply warm (tropical) environments. MAGNETOSTRATIGRAPHY Petromagnetic and Magnetic– Mineralogical Investigations The petromagnetic and magnetic–mineralogical investigations included the study of magnetic susceptibility (K) and its anisotropy (AMS), measurement of remanent magnetization (Jn), experimental magnetic saturation with subsequent determinations of remanent magnetization of saturation (Jrs) and remanent coercive force (Hcr), and differential thermomagnetic analysis (DTMA). K was measured on MFK1-FB equipment (kappabridge), Jn was measured on a JR-6 spin magnetometer, and a TAF-2 thermoanalyzer of fractions (“magnetic weights”) was used for DTMA. The AMS analysis was conducted using the Anisoft 4.2 program. The composite section is well differentiated with respect to its petromagnetic properties (Fig. 8). The lower (carbonate) part of the section (Members 1–9) is slightly magnetized (K = 0.2–8 × 10–5 SI units, Jn = 0.002–0.2 × 10–3 A/m). The overlying terrigenous sediments (Members 10– 26) are characterized by higher K values increasing up the section to 25–33 × 10–5 SI units in Members 20–22 and then gradually decreasing to 11–15 × 10–5 SI units in Member 26. The similar trend in the distribution of Jn values is complicated by the presence of several intervals with abnormally high values, which results in the increase in the Konigsberger ratio (Q factor) to several units, while its background values never exceed fractions of unity. The upper carbonate members (27 and 28) are slightly magnetic (K = 1–3 × 10–5 SI units, Jn = 0.01–0.1 × 10 3 A/m). The K/Jrs parameter proportional to the average size of ferromagnetic particles is lowest in clays of the Bechku Formation (Members 19–24) and highest in limestones of Members 3 and 4 and terrigenous–carbonate varieties of Members 26 and 27. Hcr value is highly variable (20–325 × 103 A/m), being highest in some carbonate varieties of Members 1–4, 9, 27, and 28. Many samples are magnetically soft (saturation is achieved in fields of ~100 × 103 A/m) (Fig. 9a), which is determined by the presence of magnetite or close minerals. The magnetically hard samples do not achieve saturation in fields up to 600 × 103 A/m (Fig. 9b), which is explained by the presence of hematite or strongly dehydrated Fe hydroxides. On saturation curves obtained for limestones from the lower part of the section (Members 1–3), both phases (magnetically soft and hard) are well recognizable (Fig. 9c). The presence of magnetite is also evident on DTMA curves. Unfortunately, the peak near 550– 578°C corresponding to the Curie point of Fe3O4 or close minerals is masked on all of them by thermomagnetic effects related likely to pyrite. The presence of the latter is evident from the magnetization increment above 400°C owing to transformation of FeS2 into Fe3O4 (Figs. 9d, 9e). The magnetically hard phase (hematite, martite, or dehydrated Fe hydroxides) is reflected in the poorly expressed peak on DTMA curves in the area of 650°C (Fig. 9e). The ASM patterns are different in carbonate and terrigenous varieties. Limestones exhibit chaotic magnetic patterns (Fig. 9f), while in clays and sandstones projections of short axes of magnetic ellipsoids are regularly grouped in the center of the stereographic projection and projections of long axes strive to the equator and are marked by slight but distinct anisotropy along the sublatitudinally oriented line that corresponds with the strike of beds (Fig. 9g). In order to exclude suspicions that chaotic AMS patterns (Fig. 9f) are determined by the instrumental error in measurements of slightly magnetic limestones (mostly К < 3 × 10–5 SI units), we have analyzed two selections of samples with the measurement errors of <5% and >5%, respectively. The testing revealed that the magnetic patterns in both selections are the same. The anisotropy of magnetic susceptibility in limestones is most likely determined by the irregular distribution of ferromagnetic minerals due to their concentration in bioturbations, which are characteristic of carbonate rocks in the examined section. The enrichment of ichnofossils with ferromagnetic minerals is explained by the concentration of biogenic magnetite in many crustacean organisms (Biskirk and O’Brian, 1989); in addition, some burrows become populated by magnetite-producing bacteria (Stolz et al., 1986). Bioturbation of sediments provides no obstacle for paleomagnetic investigations since ferromagnetic particles remain oriented in accordance with the field in semiliquid sediments acquiring the post-depositional detrital remanent magnetization Jn. The anisotropy of long axes of magnetic ellipsoids in the terrigenous part of the section indicates com- STRATIGRAPHY AND GEOLOGICAL CORRELATION Vol. 23 No. 2 2015 Member Thickness, m Gaps in sampling, m Polarity K, 10–5 SI units 0 10 20 30 Jn, 10–3 A/m K/Jrs, 10–5 m/A 0 1 2 3 4 5 6 7 –0.05 0 2420 2943 28 30 27 15 26 30 3 ? 25 15 22 24 7.6 2940 17 23 8.4 15 19.96 21.84 40.97 22 5.5 4 21 18 2952 11–12 2948 3.6 1.5 2 1 10 2.8 9 11.5 45 4 2.7 2949 6 5 65 21.2 0.50 0 50 150 250 350 Jrs, 10–3 A/m Q 0 1 2 3 0 1000 2000 2947 6 6.25 3 63 2 12 10 50– 60 181 >50 1 4.5 2950 2949 7–8 7 2947 2015 17 0.3 1.65 16 15 14 13 20.3 15 5.6 2 2952 2944 19 4 18 5 2950 2951 No. 2 9 20 8 0.25 Hcr, 103 A/m NEW DATA ON BERRIASIAN BIOSTRATIGRAPHY, MAGNETOSTRATIGRAPHY Vol. 23 Fig. 8. Composite magnetostratigraphic Berriasian section of central Crimea: paleomagnetic and petromagnetic characteristics. For legend, see Fig. 4. STRATIGRAPHY AND GEOLOGICAL CORRELATION Outcrops 182 ARKADIEV et al. pression of rocks in the submeridional direction, which is consistent with widely shared views on geodynamics of the Crimean Peninsula at the neotectonic stage (Nikishin et al., 1997). In contrast to hard limestones, clays and clayey sands changed their magnetic structure in response to collisional compressions. At the same time, judging from the vague anisotropy of long axes, deformations which they experienced could not have resulted in significant distortion of Jn vectors able to affect polarity determination. An atypical AMS distribution is documented in outcrop 2952 represented by alternating carbonate and terrigenous rocks. As in the remaining section, limestones in this outcrop are characterized by chaotic magnetic patterns. At the same time, projections of short axes in clays (Members 13, 15, 17) are displaced from the center of the stereographic projection and are arranged along a large circle in the SE–NW direction, while long axes are distributed transversely in the SW– NE direction (Fig. 9h). Such magnetic patterns indicate that these rocks were subjected to extremely intense deformations due to local compression along the SE–NW axis (Lanza and Meloni, 2006), which was probably accompanied by the formation of the upthrown (thrust) structure. This conclusion is indirectly confirmed by development of cleavage in limestones (Member 18) and poor quality of the paleomagnetic record in this outcrop. In such a situation, the data on this interval of the section, including documented succession of layers, should be taken with precaution. It is conceivable that limestones with intense cleavage represent an exotic block (klippe) of older strata, which is consistent with the paleontological data: the foraminiferal assemblage from Member 18 differs from that in underlying terrigenous rocks, being identical to the assemblage in older limestones. Similar AMS patterns are observed in clays, siltstones (upper part of Member 25 and Member 26), and marlstones (Member 27) cropping out in the Mezhgor’e and Pasechnoe areas (outcrops 2943, 2420): projections of short axes of magnetic ellipsoids demonstrate as in outcrop 2952 a tendency for the shift along the large circle, although they are less remote from the center of stereographic projection (Fig. 9i). This indicates that unconsolidated plastic sediments are deformed by compression in the SE–NW direction (as in outcrop 2952, but to a lower degree). Thus, the AMS investigations make it possible to obtain nontrivial information on intensity of tectonic movements, which affected rocks in the region under consideration, and, in fact, to specify the structure of the Berriasian section in central Crimea. At the same time, outcrops 2952, 2943, and 2420 (Members 13– 18, 26–28) appeared to be unfavorable objects for paleomagnetic investigations. As a whole, variations in petromagnetic parameters through the composite section promote individualization of its particular intervals and recognition of sedimentation cyclicity (Fig. 8), which is of undoubted interest for substantiation of stratigraphic units and paleogeographic reconstructions. Paleomagnetic Investigations The paleomagnetic investigations were aimed at obtaining magnetic polarity characteristics of the section. Each of 181 oriented samples taken from different stratigraphic levels (Figs. 3, 4) was cut into three or four cubes with edges of 20 mm. The laboratory investigation of the samples included Jn measurements on the JR-6 spin magnetometer after a series of successive magnetic demagnetization sessions by an alternating field mostly up to 45–60 mT with a step of 5 mT (H demagnetization) on LDA-3 AF equipment and temperature ranging from 100°C to 500–550°C with a step of 50°C (T° demagnetization) in an Aparin furnace. The samples were subjected to the impact of high fields and temperatures until their magnetization became comparable with the instrumental measurement accuracy. For the control over the possible laboratory magnetization of samples, two cubes from the same sample with mutually opposite orientation along two Jn constituents were placed into the furnace. For the control over the quality of results, some samples were measured on the cryogenic magnetometer (2G Enterprises) in the Paleomagnetic Laboratory (Institute of Petroleum Geology and Geophysics, Siberian Branch, Russian Academy of Sciences, Novosibirsk). The data were processed using the Remasoft 3.0 program. The natural remanent magnetization (Jn) retained after the impact of strong fields and high temperatures was accepted as the stable component of magnetization (SCM) (Figs. 10a, 10b). Carbonate rocks of the basal part of the section appeared to be most favorable for paleomagnetic investigations. In samples from these rocks, the stable components of magnetization projected onto the upper hemisphere are usually defined with the appropriate accuracy (maximum deviation angles up to 15°) after both demagnetization procedures (Fig. 10a). The results of thermal demagnetization of samples from Members 1–3 yield better paleomagnetic statistics as compared with that for backup samples, where Jn was Fig. 9. Results of the magnetic–mineralogical analysis. (a–c) Curves of magnetic saturations; (d, e) DTMA curves (integral curves and first derivatives according to thermomagnetic analysis curves); (f–j) distributions of directions for axes of anisotropy of magnetic susceptibility (in the stratigraphic coordinate system) for limestones (f) and terrigenous rocks (g) from outcrops 2952 (h) and 2943 (i). DTMA was conducted simultaneously for several lithologically and magnetically similar samples. (1, 2) Long (K1) and short (K3) axes of ellipsoid of anisotropy of magnetic susceptibility, respectively. STRATIGRAPHY AND GEOLOGICAL CORRELATION Vol. 23 No. 2 2015 Jrs, 10–3 A/m 80 (b) 400 500 600 H, 103 A/m 2949-4 (c) 0 100 200 300 400 500 600 H, 103 A/m –3 Jrs, 10 A/m 2950-3 30 0 –2 N = 220 270 90 2 1 0 –2 –3 –6 –5 (e) 3 combined samples 2947-3, 10 J/ Ts eco nd 2 he ati ng ses sio n 10 8 6 4 1 2 100 200 300 400 500 600 700 –1 –2 0 –1 –3 dJ/ dT –2 sec ond hea ting sess ion 180 –3 N N (g) N (h) (i) N = 273 270 –1 –4 A/m (first heating session) 3 0 –5 ssion ating se first he dJ/dT (f) se ssi on –4 J, 10 4 N he at in g –7 0 100 200 300 400 500 600 H, 103 A/m (first heating session) 1 2 se co nd –7 2947-10 dJ/dT, 10–7 A/m 300 200 100 dT –3 20 10 100 200 300 400 500 600 700 dJ / session 200 100 0.5 1.0 –1 (first heating session) 40 dJ/dT, 10–7 A/m 2943-11 1.5 dJ/dT, 10–6 A/m 300 (second heating session) 200 1.0 dJ/dT, 10–7 A/m J, 10–7 A/m (second heating session) 0 100 2.0 1.5 se co fir nd st h he ea ati tin ng gs ess se ssi ion on heating session 2943-5 J/ T combined samples 2940-21, 22, 25 J/ T J/T firs t 40 2.5 st heating dJ/dT fir J, 10–6 A/m (first heating session) 2952-1 100 2.0 (d) (second heating session) Jrs, 10–3 A/m 80 (a) 183 J, 10–5 A/m (second heating session) NEW DATA ON BERRIASIAN BIOSTRATIGRAPHY, MAGNETOSTRATIGRAPHY N = 28 90 270 180 STRATIGRAPHY AND GEOLOGICAL CORRELATION N = 59 90 270 180 Vol. 23 90 180 No. 2 2015 184 ARKADIEV et al. destroyed by the alternating field (table). The relatively high precision parameter and steeper (than after H demagnetization) paleomagnetic inclination are determined by the fact that magnetization related to hard ferromagnetic minerals is destroyed by temperature more effectively. This is evident from the correlation between the precision parameter and Hcr values in results of demagnetization by the alternating field: in the magnetically softest samples, precision parameters are the highest and paleomagnetic directions correspond to the vector derived from thermal demagnetization sessions, the precision parameter decreases with addition of magnetically harder samples to the selection, and the average paleomagnetic inclination becomes gentler (table). In terrigenous varieties, the reliability of paleomagnetic measurements is worse than in limestone, although the K and Jn values in them are substantially higher. No stable component was defined in approximately one-third of terrigenous samples. The remaining samples may be divided into two groups. In samples of the first group, Jn projections either were initially located on the northern sector of the lower hemisphere or left it after the session of demagnetization by weak temperature and alternating field. Such behavior of paleomagnetic vectors during demagnetization was interpreted as the presence of the Jn component corresponding to the reversed polarity (R). In some sample, SCM is anomalous: for example, southerly declination combined with positive inclinations in Sample 2940-30 (Fig. 10c). In samples of the second group, projections of paleomagnetic vectors remained in the northern sector of the lower hemisphere up to the last session of demagnetization (Fig. 10b). These directions are interpreted as corresponding to normal polarity of the magnetic field (N). We believe that the significant scatter of R vectors (Figs. 10e, 10f) is determined by the different degree of SCM “contamination” with the stabilized secondary component related to products of oxidation of magnetic grains and by impossibility to separate the components during demagnetization. This effect leaves the paleomagnetic statistics on normally magnetized samples practically unchanged (Fig. 10g, table) since SCMs corresponding to normal polarity are close to the direction of rock magnetization reversal by the recent field, although statistically being different (table). It is of importance that the results of the sample magnetization reversal by the alternating field and temperature demonstrate principal similarity (Figs. 10c, 10d). This increases substantially the reliability of paleomagnetic measurements as compared with the results based only on one of the demagnetization procedures. Nevertheless, the anomalous reversed polarity is shown as the half-shaded paleomagnetic column in Figs. 3 and 4. The rejected and unreliable polarity determinations are scattered more or less regularly through the section; therefore, the absence of information hardly affects its paleomagnetic structure. Small gaps in polarity determinations and single intervals with its opposite sign were ignored during compilation of the composite paleomagnetic column (Figs. 2, 11). Owing to the biostratigraphic control, identification of the paleomagnetic column with successive magnetic chrons was successful (at least for Members 1–23) despite large unexposed intervals and doubts in the reliability of results obtained for some intervals of outcrops 2952, 2943, and 2420. The long R magnetic zone corresponding to the largest part of the occitanica Zone (and, probably, uppermost jacobi Zone) and N magnetic zone in the uppermost part of the occitanica Zone represent undounbted analogs of Chron M17 (M17r and M17n, respectively). The Dalmasiceras tauricum Subzone is an analog of the Dalmasiceras dalmasi Subzone of the Mediterranean standard and consequently Chron M17n cannot correspond to large gaps in sampling between Members 3 and 4 or 8 and 9 (Figs. 2, 11), which are located considerably below the first finds of Dalmasiceras representatives. The overlying R magnetic zone corresponds to Chron M16r established previously in the Feodosiya area (Arkadiev et al., 2010) (Fig. 11). The examined section includes also analogs of Chrons M16n and M15r (it is conceivable that M15n and M14r are included as well), although their position cannot be determined because of large gaps in sampling (Fig. 11). The obtained data make it possible to carry out magnetostratigraphic correlation of the Berriasian section of central Crimea and the Berriasian stratotype Fig. 10. Results of the component analysis. (a, b) (From left to right) stereographic images of changes in Jn vectors during demagnetization sessions, Zijderveld diagrams, demagnetization plots; (c, d) comparison of results of demagnetization by the alternating field (h) and temperature (t); (e–g) stereographic projections of SCM corresponding to R polarity in Members 1–3 (limestones) according to results of T° and H demagnetization (e), R polarity in Members 5–25 (terrigenous rocks) according to results of T° and H demagnetization (f), R polarity in Members 1–3 (limestones) according to results of H demagnetization of magnetically softest samples (Hcr = 19.6– 26.8 × 103 A/m) and T° demagnetization, and N polarity in Members 5–25 (terrigenous rocks) according to results of T° and H demagnetization (g). All the Zijderveld diagrams and Jn stereographic projections are presented in the stratigraphic coordinate system. (1, 2) Jn projections in stereograms on the lower (1) and upper (2) hemispheres; (3, 4) projections of average SCM directions for all R and N populations of vectors, respectively; (5) projections of directions of rock magnetization reversal by the recent geomagnetic field (“crosses” of magnetization reversal). Paleomagnetic statistics for the stereogram (c) and interpretation of statistical parameters are presented in the table. STRATIGRAPHY AND GEOLOGICAL CORRELATION Vol. 23 No. 2 2015 NEW DATA ON BERRIASIAN BIOSTRATIGRAPHY, MAGNETOSTRATIGRAPHY (a) N J/Jmax 1.0 0.8 E 0.6 E 0.4 0.2 Jmax = 35.1e–06 A/m W W 0 180 N Sample 2949-8 S Base N Top N N Top E E W W 180 N Sample 2944-5 Sample 2940-30 h (d) J/Jmax 1.0 0.8 Jmax = 41.0e–03 A/m 0.6 0.4 0.2 h t 180 180 N N Sample 2943-8 h t t Sample 2940-60 E E jr-6 J/Jmax 1.0 0.8 0.6 0.4 Jmax = 1.18e–03 A/m 0.2 0 jr-6 SQUID Sample 2944-4 SQUID 100 200 300 400 500 600 Division value = 175.e–06 A/m °C S Base 180 (e) t Sample 2944-7 S Base N Top W W h 0 10 20 30 40 50 60 70 mT Division value = 7.89e–03 A/m t Sample 2947-10 10 20 30 40 50 60 mT Division value = 42.9e–06 A/m S Base Sample 2940-21 t Sample 2952-13 J/Jmax 1.0 0.8 0.6 0.4 J = 256.e–06 A/m 0.2 max 0 (b) h h E E N Sample 2950-5 100200300400500 °C Division value = 5.13e–06 A/m W W 180 N (c) Sample 2947-10 N Top 185 N (f) N N (g) 1 n = 40 D = 169.1° I = –28.5° k = 1.6 α95 = 29.9° n = 47 D = 176.3° I = –41.4° k = 6.3 α95 = 9.0° 2 270 90 3 4 5 180 180 STRATIGRAPHY AND GEOLOGICAL CORRELATION 180 Vol. 23 No. 2 2015 186 ARKADIEV et al. in France (Galburn, 1985) (Fig. 11) and combined with the available data on eastern Crimea (Arkadiev et al., 2010; Bagaeva et al., 2011; Guzhikov et al., 2012) allow the statement that analogs of all the Berriasian magnetic chrons are present in Crimea. The ancient nature of the stable component of magnetization (SCM) is substantiated by the following arguments. (1) The direction of geomagnetic polarity is independent of both the lithological composition of rocks and variations in their petromagnetic properties (Figs. 2, 8). This does not prove the hypothesis of the old magnetization nature, but is consistent with the latter since the geomagnetic reversal is a global phenomenon; therefore the probability of interrelations between magnetic polarity and lithological–magnetic properties determined by local and regional factors is negligible. (2) The data on magnetic patterns of limestones (Fig. 9f) imply the confinement of the magnetically soft fraction to bioturbations, indicating the biogenic nature of magnetite particles, which could not have been formed later than the diagenetic stage. The entire section exhibits features characteristic of detrital magnetization and, in contrast, atypical of chemical magnetization: low Q factor values (fractions of unity) except for narrow intervals (to 1–5) sporadically scattered through the section (Fig. 8) and low paleomagnetic interstratal precision parameters (up to 30) (table). The substantiation of the hypothesis of sediment magnetization prior to diagenesis cessation is identical to the proof that Jn reflects the direction of the geomagnetic field in the Berriasian. (3) The most reliable paleomagnetic result obtained for limestones (table) is statistically identical to the average paleomagnetic direction available for the Late Jurassic in western Crimea (Pecherskii and Safonov, 1993) (it should be noted that, according to D.M. Pecherskii, “western Crimea” includes the Ai-Petri Yala, Karabi-Yaila, Demerdzhi, Chatyr Dag, and Cape Fiolent areas). (4) The paleomagnetic reversal (inversion) test is positive (table), which represents a very solid argument in favor of the primary nature of magnetization. (5) The paleomagnetic zonality of the composite section is well consistent with traditional views on the regime of the Berriasian geomagnetic field (Ogg and Hinnov, 2012) (Fig. 11). The index of paleomagnetic confidence for the obtained data is formally equal to 6 (of 7 possible) according to the classification in (Van der Voo, 1997) and 7 (of possible 8) according to A.N. Khramov in (Dopolneniya…, 2000). Thus, magnetic polarity determinations for the largest part of the Berriasian section (Members 1–23) deserve credence despite the generally low paleomagnetic quality of examined rocks. CONCLUSIONS (1) The contact between the carbonate Bedenekyr and terrigenous Bechku formations is described for the first time for central Crimea with the age of the upper part of the former unit attributed to the Berriasian occitanica Zone being specified. (2) On the basis of the combined paleontological and magnetostratigraphic data, the Malbosiceras chaperi Beds are attributed to the occitanica Zone. (3) Six successive foraminiferal assemblages are defined through the Berriasian section (from the base upward): (1) Everticyclammina virguliana–Retrocyclammina recta–Bramkampella arabica; (2) Lenticulina muensteri; (3) Quadratina tunassica; (4) Triplasia emslandensis acuta; (5) Lenticulina andromede; (6) Conorboides hofkeri. (4) The ostracod assemblages provide basis for defining the following biostratigraphic units in the Beriassian section (from the base upward): Costacythere khiamii–Hechticythere belbekensis Beds correlated partly with the ammonite occitanica Zone and the Costacythere drushchitzi–Reticythere marfenini Beds correlated partly with the ammonite boissieri Zone. (5) The dinocysts assemblage allows the Phoberocysta neocomica Beds correlated partly with the ammonite occitanica and boissieri zones to be defined. (6) A series of isolated outcrops (Novoklenovo, Balki, and Mezhgor’e settlements) are united into a composite section, which represents now the most complete Berriasian succession for central Crimea. Owing to magnetostratigraphic data obtained for this composite section, the presence of all the Berriasian magnetic chrons in central and eastern Crimea is substantiated for the first time. (7) On the basis of paleomagnetic data, the Berriasian section of central Crimea is correlated with its stratotype in the Mediterranean region with the position of standard Berriasian zones being specified. (8) The established anisotropy in magnetic susceptibility is used for reconstructing directions of deformations of terrigenous (clayey) rocks in response to tectonic movements. ACKNOWLEDGMENTS We are grateful to S.V. Lobacheva (posthumously) for identifying brachiopods, V.A. Perminov (Center of Learning Youth (TSENTUM) Intellekt, Feodosiya, Russia) for his help in organizing field works, A.Yu. Kurazhkovskii (Borok Geophysical Observatory) for help in conducting magnetic–mineralogical investigations, and N.V. Platonova (assistant to the director of the Resource Center X-ray Diffraction Research Methods of St. Petersburg State University) for accomplishing the X-ray phase analysis of samples. STRATIGRAPHY AND GEOLOGICAL CORRELATION Vol. 23 No. 2 2015 Statistical parameters of the distribution of the stable component of magnetization (SCM) directions No. 2 Iav (°) k α95 (°) R 33 177.9 –37.1 5.0 12.5 Hcr = 19.6–26.8 × 103 A/m R 5 177.5 –45.7 30.7 14.0 Hcr = 19.6–27.7 × 103 A/m R 7 182.6 –39.5 11.3 18.7 Hcr = 19.6–30.9 × 103 A/m R 9 182.9 –38.2 10.6 16.6 R 14 172.0 –47.9 16.1 10.2 Stable component of magnetization (SCM) calculated using H demagnetization data on magnetically softest R samples (Hcr =19.6–26.8 × 103 A/m) and T° demagnetization 19 173.5 –47.4 19.0 7.9 Magnetically soft T° demagnetization 2015 Members 5–28 (terrigenous rocks) Polarity Dav (°) H demagnetization All samples Hcr = 45.4 – 325.4 × 103 A/m Members 1–3 (limestones) Vol. 23 n N When an angle exceeds the Results of the reversal test error value (±), the vectors (McFadden demonstrate significant difand McElhinny, 1990) ference; in the opposite situation, they are statistically coincident (Debiche and Watson, 1995) A (°) Ac (°) Cl Angle with Angle with RF (°) SCM + 180 (°) 5.6 91 SCM + 180° 1.7 46.8 353.5 47.9 Magnetization reversal by the recent field (RF) 2 4.3 58.7 Western Crimea (J3) (Pecherskii and Safonov, 1993) 11 352 47 14.7 4.0 8.8 B 11.8 ± 4.4 4.5 ± 6.7 (A) angle between vectors 12.5 ± 6.7 (Ac) critical angle (Cl) classification 10 102.8 4.5 12.6 ± 6.1 13.7 ± 3.2 1.1 ± 6.8 NEW DATA ON BERRIASIAN BIOSTRATIGRAPHY, MAGNETOSTRATIGRAPHY STRATIGRAPHY AND GEOLOGICAL CORRELATION (n) number of samples in the selection (Dav, Iav) average paleomagnetic declination and inclination, respectively (k) precision parameter (α95) radius of the vector confidence circle The amplitude of the secular geomagmetic variation (10%, according to V.G. Bakhmutov, 2006; (1200) summer variation is characterized by the amplitude of 8%). 187 Tirnovella occitanica 188 m 450 400 350 300 250 200 150 100 50 0 Fauriella boissieri Member Polarity ARKADIEV et al. ? ? Stage Zone Polarity Berriasian Tirnovella occitanica T. subalpina Stage Fauriella boissieri B. privasensis D. dalmas M. paramimounum Eastern Crimea Sultanovka Berriasian– Valanginian (Bagaeva et al., 2011) (Arkadiev et al., 2010) Zavodskaya Balka 50 0 Berriasian F. boissieri P. grandis Vol. 23 B. picteti Zone Subzone B. callisto Polarity Tithonian Stage Berriasian Berriasella jacobi Subthurmannia occitanica Zone Subthurmannia boissieri Polarity M14 M15 M16 M17 M18 M19 No. 2 Ma 140 141 142 143 144 145 2015 Magnetochronological scale 28 27 26 25 24 23 22 21 20 19 18 – 10 9 8–4 3 2 1 STRATIGRAPHY AND GEOLOGICAL CORRELATION Dinocysts beds (Ogg and Hinnov, 2012) Ostracod beds Phoberocysta neocomica Berriasian stratotype (France) Costacythere drushchitzi–Reticythere marfenini (Galbrun, 1985) Foraminiferal beds/ assemblages ? Costacythere khiamii–Hechticythere belbekensis Conorboides hofkeri Lenticulina andromede ? Lenticulina Quadratina muensteri tunassica Triplasia emslandensis acuta Central Crimea, Russia Beds with Zeillerina baksanensis Beds with Symphythiris arguinensis Riasanites crassicostatum Neocosmoceras euthymi Dalmasiceras tauricum Beds with Malbosiceras chaperi grandis Textularia crimica–Belorussiella taurica Evirticyclammina virguliana, Rectocyclammina recta, Bramkampella arabica Composite section (this work) Stage Zone Subzone, beds with fauna (Arkadiev et al., 2012) Berriasian B. jacobi Magnetic chrons NEW DATA ON BERRIASIAN BIOSTRATIGRAPHY, MAGNETOSTRATIGRAPHY 189 Fig. 11. Correlation of magnetostratigraphic data available for the Berriasian section of central and eastern Crimea with the Berriasian stratotype in southeastern France and standard magnetostratigraphic scale. In the paleomagnetic column of the composite section of central Crimea, gaps 5 m wide and less in determinations of polarity are not shown. For legend, see Fig. 4. This work was supported by the Russian Foundation for Basic Research (project nos. 11-05-00405-a, 13-05-00745-a, 14-05-31152_a_mol) and Ministry of Education and Science of the Russian Federation in the base part (project 1582) and the scientific field (project 1757). Reviewers M.A. Rogov, A.Yu. Kazanskii, and V.A. Zakharov REFERENCES Andreev, Yu.N. and Ertli, Kh.Yu., Some Cretaceous ostracods of Central Asia and related species of Europe, Vopr. Mikropaleontol., 1970, no. 13, pp. 95–121. Andreev, Yu.N., Cretaceous ostracods of Central Asia (composition, distribution, evolution, geological significance), Doctoral (Geol.-Mineral.) Dissertation, Moscow: MGU, 1986. Arkadiev, V.V., Bagaeva, M.I., Guzhikov, A.Yu., et al., Bioand magnetostratigraphic characterization of the Upper Berriasian section “Zavodskaya balka” (Eastern Crimea, Feodosiya), Vestn. Sankt-Peterburg. Univ., Ser. 7. Geol. Geogr., 2010, Iss. 2, pp. 3–16. 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