Abstract
The Emet borate deposits were formed in two separate basins, possibly part of an interconnected lacustrine playa lake, in areas of volcanic activity, fed partly by thermal springs and partly by surface streams. The borates are interlayered with tuff, clay and marl. Limestone occurs above and below the borate lenses. Sediments in both basins are similar but borate minerals show different mineralogical and geochemical features in the two basins.
The Emet borate deposits are the only deposits known to contain any of the minerals veatchite-A, tunellite, teruggite and cahnite. Principal minerals are colemanite, with minor ulexite, hydroboracite and meyerhofferite.
Thermal springs associated with local volcanic activity are thought to be the source of the borates. The initial brines from which the borates crystallized are deduced to have been high in sulphite and sulphate, low in chloride, and hence it is assumed that the initial brines were fed at all times by abundant calcium and boron with minor amounts of arsenic, strontium and sulphur. Realgar, celestite and native sulphur are almost ubiquitous in borates and sediments, and appear to have formed at all stages during deposition and diagenesis.
The early colemanite, meyerhofferite, ulexite and teruggite nodules were probably formed directly from brines penecontemporaneously within the unconsolidated sediments below the sediment/water interface, and continued to grow as the sediments were compacted. Later generations of colemanite occur in vugs, veins and as fibrous margins to colemanite nodules. Tunellite appears to have formed during diagenesis with enrichment of Sr in some places. Diagenetic alterations include the partial replacement of colemanite by veatchite-A, cahnite, hydroboracite and calcite.
Similar content being viewed by others
References
Akkuş, M.F.: Geology of the Kütahya-Gediz area. Turkey Miner. Research Explo. Inst. Bull. 58:21–30 (1962)
Aristarain, L.F., Hurlbut, C.S. Jr.: Teruggite 4CaO · MgO · 6B2O3 · As2O5 · 18 H2O, a new mineral from Jujuy, Argentina. Am. Mineral. 53:1815–1827 (1968)
Baysal, O.: Tunellite, a new hydrous strontium borate from the Sarıkaya borate deposits in Turkey. Bull. Mineral Research and Explo. Institute of Turkey 79:22–29 (1972)
Bowser, C.J.: Geochemistry and petrology of the sodium borates in the non-marine evaporite environment. Ph. D. dissertation, University of California, Los Angeles (1965)
Bowser, C.J., Dickson, F.W.: Chemical zonation of the borates of Kramer, California. Second Symp. on Salt. 1:122–132, Northern Ohio Geol. Soc., Cleveland Ohio (1966)
Braitsch, O.: Über p-Veatchit, eine neue Veatchit-Varietät aus dem Zechsteinsalz. Beitr. Mineral. u. Petrogr. 6:352–356 (1959)
Bugge, Jens A.W.: Minerals from the skarn iron ore deposits at Arendal, Norway. Cahnite from Kladeborg mine. K. Norske Vidensk, Selskab. Förh. 24:79–81 (1951)
Embrey, P.G.: Cahnite from Capo di Bove, Rome. Min. Mag. 32:666–668 (1960)
Erd, R.C., Morgan, V., Clark, J.R.: Tunellite, a new hydrous strontium borate from the Kramer borate district, California. Prof. Pap. U.S. Geol. Surv. 424-C:294–297 (1961)
Erinç, S.: The Gediz earthquake of 1970. In: Geology and History of Turkey, A.S. Campbell, Ed., pp. 443–451. The Petroleum Exploration Society of Libya, Tripoli (1971)
Gawlik, J.: Borate deposits of Emet district. M.T.A. Rep. no. 2479 (unpublished) (1956)
Harvey, P.K., Taylor, D.M., Hendry, R.D., Bancroft, F.: An accurate fusion method for the analysis of rocks and chemically related materials by X-ray fluorescence spectrometry. X-Ray Spectrometry 2:33–44 (1973)
Helvacı, C.: Contribution to discussion of a paper by Inan, K., Dunham, A.C. and Esson, J. Trans. Inst. Min. Metall. (Section B. Appl. earth sci.) 83B:36 (1974)
Helvacı, C.: Geology, mineralogy and geochemistry of the borate deposits and associated rocks at the Emet Valley, Turkey. Ph. D. dissertation, University of Nottingham, England (1977)
Helvacı, C.: A review of the mineralogy of the Turkish borate deposits. Mercian Geol. 6:257–270 (1978)
Helvacı, C.: Unpublished research materials and data (1982)
Helvacı, C., Firman, R.J.: Geological setting and mineralogy of Emet borate deposits, Turkey. Trans. Inst. Mining Metall. (Section B. Appl. earth Sci.) 85B:142–152 (1976)
Holzer, H.: Geological report of the Beyce-54/4 and Simav-71/2 area. M.T.A. Rep. no. 2366 (unpublished) (1954)
Inan, K., Dunham, A.C., Esson, J.: Mineralogy, chemistry and origin of Kırka borate deposit, Eskişehir Province, Turkey. Trans. Inst. Min. Metall. (Sect. B: Appl. earth sci.), 82B:114–123 (1973)
Kitano, Y.: Geochemistry of calcareous deposits found in hot springs. J. Earth Sci., Nagoya Univ. 11:68–100 (1963)
Kumbasar, I.: Veatchite-A, a new modification of veatchite. Am. Mineral. 64:362–366 (1979)
Leake, B.E., Hendry, G.L., Kemp, A., Plant, A.G., Harrey, P.K., Wilson, J.R., Coats, J.S., Aucott, J.W., Lünel, T., Howarth, R.J.: The chemical analysis of rock powders by automatic X-ray fluorescence. Chem. Geol. 5:7–86 (1969/1970)
Malinko, S.V.: First find of cahnite in the U.S.S.R. Dokl. Acad. Sci. U.S.S.R., Earth Sci. Sect., 166, 116–120. Transl. from Dokl. Acad. Nauk U.S.S.R., 166:695–697 (1966)
Muessing, S.: Recent South American borate deposits. In Second symp. on salt (Cleveland, Ohio: Northern Ohio Geological Society), 1:151–159 (1966)
Negro, A.D., Kumbasar, I., Ungaretti, L.: The Crystal Structure of Teruggite. Am. Mineral. 58:1034–1043 (1973)
Özpeker, I.: Western Anatolian borate deposits and their genetic studies. Ph. D. dissertation (Turkish text). Technical University of Istanbul (1969)
Palache, C., Bauer, L.H.: Cahnite, a new boroarsenate of calcium from Franklin, New Jersey. Am. Mineral. 12:149–153 (1927)
White, D.E.: Thermal waters of volcanic origin. Geol. Soc. Amer. Bull. 68:1637–1658 (1957)
White, D.E., Hem, J.D., Waring, G.A.: Chemical composition of subsurface waters. In: Data of geochemistry, 6th Ed. U.S. Geol. Survey, Prof. Paper, 440-F, p. 67 (1963)
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Helvacı, C. Occurrence of rare borate minerals: Veatchite-A, tunellite, teruggite and cahnite in the Emet borate deposits, Turkey. Mineral. Deposita 19, 217–226 (1984). https://doi.org/10.1007/BF00199788
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00199788