Silver-cobalt mineralization in the Upper Seymchan ore cluster, Northeastern Russia
Tóm tắt
This paper is focused on the Early Cretaceous Ag-Bi-Co-sulfoarsenide mineralization atypical of northeastern Asia, which contains diverse Co-Ni sulfoarsenides, Se-bearing Bi sulfotellurites, and Ag-Bi-Pb sulfosalts. The Upper Seymchan ore cluster is located at the boundary between the Paleozoic Omulevka Terrane of carbonate platform and the In’yali-Debin Synclinorium of the Kular-Nera Terrane. These ore-bearing sequences are represented by the Middle Jurassic terrigenous rocks that rest upon the Upper Triassic sandshale rocks of the upper structural stage. The sedimentary rocks are cut through by high-Al granitic plutons and younger granite-porphyry dikes. The orebodies that are superposed on igneous rocks were formed during (1) the quartz-chlorite-tourmaline stage of metasomatic alteration, (2) the main economic tourmaline-chlorite-quartz-sulfoarsenide vein stage, (3) the polysulfide-quartz stage with Ag, Se, Bi minerals, and (4) the postore quartz-calcite stage with fluorite. The epithermal veins of festoon chalcedony-like quartz with Sb-bearing arsenopyrite occupy a special position. In particular orebodies, the chlorite-quartz ore veins dominate at the upper levels, whereas the quartz-tourmaline veins occur at the lower levels. Wall-rock alteration is represented by metasomatic chloritization and tourmalinization up to the formation of monomineralic metasomatic zones. Sulfides and sulfoarsenides are distinguished by anomalous enrichment of sulfur in the light isotope (δ34S = −12.8 to −16.7‰) in contrast to the sulfur isotopic composition of Sb-asenopyrite (−1.7‰) from the genetically different epithermal veins. The oxygen isotopic composition of calcite (the third stage) is uniform at all studied deposits and reveals a tendency to updip enrichment in δ18O within a vertical interval of 200 m. Quartz from ore-bearing and epithermal veins has an almost identical δ18O value (±2‰) but differs from quartz at the tin deposits related to granites of the Canyon Complex and enriched in the light isotope in its oxygen isotopic composition. The mineralization in the Upper Seymchan ore cluster, which is genetically linked to the Early Cretaceous calc-alkaline dike suite pertaining to the period of postcollision late orogenic extension, is formed from magmatic fluids diluted with meteoric water (salinity reaches 20 wt % NaCl equiv) at temperatures varying from 400-380°C to 220-150°C and under a pressure of 970 to 60 bar. The direct vertical mineral zoning is expressed in the change of mineral species with depth and in variable compositions and properties of particular minerals.
Tài liệu tham khảo
Bodnar, R.J. and Vityk, M.O., Interpretation of microthermometric data for H2O-NaCl fluid inclusions, in Fluid Inclusions in Minerals: Methods and Applications, Pontignano-Siena, 1994, pp. 117–130.
Borisenko, A.S., Study of salt composition of fluid inclusions in minerals using cryometric method, Geol. Geofiz., 1977, vol. 18, no. 8, pp. 16–27.
Borisenko, A.S., Lebedev, V.I., and Tyul’kin, V.G., Usloviya obrazovaniya gidrotermal’nykh kobal’tovykh mestorozhdenii (Formation Conditions of Hydrothermal Cobalt Deposits), Novosibirsk: Nauka, 1984.
Borisenko, A.S., Borovikov, A.A., Zhitova, L.M., et al., Composition of magmatogenic fluids, factors of their geochemical specialization and ore potential, Geol. Geofiz., 2006, vol. 47, no. 1, pp. 1308–1325.
Brown, P., FLINCOR: a computer program for the reduction and investigation of fluid inclusion data, Am. Mineral., 1989, vol. 74, pp. 1390–1393.
Gamyanin, G.N., Nekrasov, I.Ya., Goryachev, N.A., et al., Mineralogical-geochemical features of silver mineralization in the Verkhoyansk-Kolyma Fold Region, Paper 1: Mineral assemblages in Silver-Antimony and Gold-Silver ores, Mineral. Zh., 1987, no. 6, pp. 5–17.
Gamyanin, G.N. and Goryachev, N.A., Cobalt arsenide mineralization in northeastern Asia: Types and genesis, in Tektonika, rudnye mestorozhdeniya i glubinnoe stroenie zemnoi kory (Tectonics, Ore Deposits, and Deep Structure of the Earth’s Crust), Yekaterinburg, 2011, pp. 45–48.
Geodinamika, magmatizm i metallogeniya Vostoka Rossii (Geodynamics, Magmatism and Metallogeny of Eastern Russia) Khanchuk, A.I., Eds., Vladivostok: Dal’nauka, 2006, vol. 1, 2.
Goryachev, N.A. and Gamyanin, G.N., Silver-rare-metal deposit type, the Verkhne-Seimchan mineral district, in Metallogeny of the Pacific Northwest: Tectonics, Magmatism and Metallogeny of Active Continental Margins. Proceedings of the Intern. IAGOD Conference, Vladivostok, pp. 1–20.
Goryachev, N.A., Zhil’nyi kvarts zolotorudnykh mestorozhdenii Yano-Kolymskogo poyasa (Quartz Veins at Gold Deposits of the Yana-Kolyma Belt), Magadan: SVKNII DVO RAN, 1992.
Goryachev, N.A., Proiskhozhdenie zoloto-kvartsevykh zhil’nykh poyasov Severnoi Patsifiki (Origin of Gold-Quartz Vein Belts in Northern Pacific), Magadan: SVKNII DVO RAN, 2003.
Goryachev, N.A., Gamyanin, G.N., Prokof’ev, V.Yu., Velivetskaya, T.A., Ignat’ev, A.V., and Leskova, N.V., Gold-antimony mineralization of the Yana-Kolyma Belt, Northeast Russia, Russian J. Pacific Geol., 2011, vol. 5, no. 2, pp. 97–110.
Gracheva, O.S. and Krylova, L.I., Structure and mineralogical features of the Verkhne-Seimchan rare-metal deposit, in Inform. Sbornik VSEGEI, 1959, no. 9, pp. 13–24.
Irber, W., The lantanide tetrad effect and its correlation with K/Rb, Eu/Eu*, Sr/Eu, Y/Ho, and Zr/Hf of evolving peraluminous granite suites, Geochim. Cosmochim. Acta, 1999, vol. 63, nos. 3/4, pp. 489–508.
Kalyuzhny, V.A., Osnovy ucheniya o mineraloobrazuyushchikh flyuidakh (Principles of Science on Mineral-Forming Fluids), Kiev: Naukova dumka, 1982.
Krutov, G.A., Mestorozhdeniya kobal’ta, in Rudnye mestorozhdeniya SSSR (Ore Deposits of the USSR), Moscow: Nedra, 1974, vol. 2, pp. 75–98.
Kryazhev, S.G., Vasyuta, Yu.V., and Kharrasov, M.K., Technique of bulk analysis of inclusions in quartz, in Mater. XI Mezhdunar. konf. po termobarogeokhimii (Proceedings of the 11th Intern. Conference on Thermobarogeochemistry), Aleksandrov: VNIISIMS, 2003, pp. 6–10.
Kuznetsov V.M. and Shpikerman V.I. Gosudarstvennaya geologicheskaya karta Rossii (novaya seriya. List R-56. Ob“yasnitel’naya zapiska (State Geological Map of Russia (New Series). Map Sheet R-56. Explanatory Notes), St. Petersburg, VSEGEI, 2008.
Lebedev, V.I., Rudnomagmaticheskie sistemy etalonnykh arsenidno-kobal’tovykh mestorozhdenii (Ore-Magmatic Systems of Reference Cobalt Arsenide Deposits), Novosibirsk: SO RAN, 1998.
Malinovsky, M.A., Gold potential of the Obkhod, Yasny, and Levoseimkanskoe cobalt ore deposits, in Geologiya i mineral’no-syr’evye resursy Severo-Vostoka Rossii: Mater. Vserossiiskoi nauchno-prakticheskoi konf. (Proceedings of All-Russia Scientific-Practical Conference: Geology and Mineral Resources of Northeastern Russia), Yakutsk, Dom SVFU, 2012, vol. 2, pp. 29–30.
Newberry, R.J., Layer, P.W., Gans, P.B., et al., Preliminary analysis of chronology of Mesozoic magmatism, tectonics, and mineralization in northeastern Russia with allowance for 40Ar/39Ar datings and data on trace elements in igneous and mineralized rocks, in Zolotoe orudenenie i granitoidnyi magmatizm Severnoi Patsifiki, T.1: Geologiya, geokhronologiya i geokhimiya (Gold Mineralization and Granitoid Magmatism of Northern Pacific, Vol. 1: Geology, Geochronology, and Geochemistry), Magadan: SVKNII DVO RAN, 2000, pp. 181–206.
Naumov, V.B., Possible determination of pressure and density of mineral-forming media from inclusions in minerals, in Ispol’zovanie metodov termobarogeokhimii pri poiskakh i izuchenii rudnykh mestorozhdenii (Use of Thermobarogeochemical Methods in Prospecting and Study of Ore Deposits), Laverov, N.P., Ed., Moscow: Nedra, 1982, pp. 85–94.
Ocherki metallogenii i geologii rudnykh mestorozhdenii Severo-Vostoka Rossii (Essays on Metallogeny and Geology of Ore deposits in Northeastern Russia), Sidorov, A.A. and Goryachev, N.A., Eds., Magadan: SVKNII DVO RAN, 1994.
Prokof’ev, V.Yu., Types of hydrothermal ore-forming systems (from fluid inclusion studies), Geol. Ore Deposits, 1998, vol. 40, no. 6, pp. 457–470.
Prokof’ev, V.Yu., K/Rb ratio in relics of ore-forming fluids, in Novye idei v naukakh o Zemle: VII Mezhdunar. konf. Tezisy dokladov (Abstracts of the 7th Intern. Conf.: New Ideas in Geoscience), Moscow: MGGRU, 2005, vol. 2, p. 94.
Savva, N.E., Mineralogical features of gold and silver mineralization in the Omsukchan district (Northeast of the USSR), Cand. Sci. (Geol.-Mineral.) Dissertation, Moscow: Moscow State Univ., 1980.
Shpikerman, V.I., Domelovaya minerageniya Severo-Vostoka Azii (Pre-Cretaceous Minerageny of Northeastern Asia), Magadan: SVKNII DVO RAN, 1998.
Sindeeva, N.D., Mineralogiya, tipy mestorozhdenii i osnovnye cherty geokhimii selena i tellura (Mineralogy, Deposit Types, and Main Features of Selenium and Tellurium Geochemistry), Moscow: AN SSSR, 1959.
Sokolova, E.A., Complex of minor intrusions in the Verkhne-Seimchan district and related mineralization, in Materialy po geologii i poleznym iskopaemym Severo-Vostoka SSSR (Proceedings on Geology and Mineral Resources of the Northeastern USSR), Magadan, 1956, issue 10, pp. 69–93.
Tektonika, geodinamika i metallogeniya territorii respubliki Sakha (Yakutiya) (Tectonics, Geodynamics, and Metallogeny in Territory of the Sakha Republic), Parfenov, L.M. and Kuz’min, M.I., Eds., Moscow: MAIK Nauka/Interperiodika, 2001.