Abstract
The Varvarinskoye copper–gold deposit, large in terms of Au and small in terms of Cu, was discovered in 1979 in the western part of the Torgai trough in Kazakhstan. It is composed of Devonian volcanosedimentary and intrusive rocks. Ore zones with a thickness from a few meters to a few tens of meters have been identified against a background of disseminated ore mineralization. They are composed of densely disseminated (porphyry) up to massive ores. The ore zones are localized in the thermal metamorphism band of volcanosedimentary and intrusive rocks, while disseminated mineralization is widespread beyond it. Ten ore mineralization types can be distinguished. The Au–Cu mineralization type is common in volcanosedimentary rocks and diorites, while the Au–Cu–Ni ores occur in serpentinites formed after thermally metamorphized intrusive rocks. Densely disseminated and massive magnetite ores are confined to skarns. Sulfide and sulfide–arsenide mineralization can also be observed. Each type of Au–Cu mineralization (pyrrhotite, chalcopyrite–marcasite–pyrite, pyrite, and gold–sulfide–arsenopyrite) can be correlated to an analog of Au–Cu–Ni mineralization (pentlandite–pyrrhotite, chalcopyrite–pentlandite–pyrite, pentlandite–pyrite, and gold–nickeline–gersdorffite). This indicates the uniform ore-forming process in serpentinites and volcanosedimentary rocks with diorites and borrowing of ore material from host rocks, at least, partially. The gold–chalcopyrite mineralization type, synchronous to the thermal metamorphism and analogous to mineralization of the alkali stage at porphyry copper deposits, has no analog in the Au–Cu–Ni mineralization. Gold is present in all mineralization types, but gold–chalcopyrite and sulfide–arsenide are the most enriched in Au. Eighty ore minerals have been found at the studied deposit. Pyrrhotite disulfidization and chalcopyrite pyritization are universal in occurrence. These processes likely led to the formation of chalcopyrite–marcasite–pyrite and chalcopyrite–pentlandite–pyrite mineralization after pyrrhotite and pentlandite–pyrrhotite types, respectively. Invisible gold present in chalcopyrite was enlarged during these processes.
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REFERENCES
Akylbekov, S. A., Votsalevskii, E. S., Gulyaev, A. P., Zhukov, N. M., Miroshnichenko, L. A., Petrov, N.N., Rakishev, B.M., and Uzhkenov, B.S., Mineragenicheskaya karta Kazakhstana masshtaba 1 : 1 000 000 (Metallogenic Map of Kazakhstan on a Scale 1 : 1 000 000) Almaty–Astana: 2007.
Antonenko, A.A., Zhukov, N.M., Gertsen, L.E., and Goikolova, T.V., Mineral and element composition of low-grade ores of the Aktogai and Bozshakol’ deposits, Izv. Akad. Nauk RK, Ser. Geol. Tekhn. Nauk, 2016, no. 4, pp. 18–27.
Aptikeev, E.R., Maslennikov, V.V., and Zhukov, I.G., Structural types of the Varvarin gold–copper–skarn deposits of Kazakhstan, Metallogeniya drevnikh i sovremennykh okeanov-2009. Modeli rudoobrazovaniya i otsenka mestorozhdenii (Metallogeny of Ancient and Modern-2009. Models of Ore Formation and Estimates of Deposits), Miass: IMinURO RAN, 2009, pp. 203–205.
Bekzhanov, G.R., Koshkin, V.Ya., Nikitchenko, I.I., Skrinnik, L.I., Azizov, T.M., and Timush, A.V., Geologicheskoe stroenie Kazakhstana (Geological Structure of Kazakhstan), Almaty, 2000.
Edwards, R. and Atkinson, K., Ore Deposit Geology, London–New York, 1986.
Naldrett, A.J., Secular variation of magmatic sulfide deposits and their source magmas, Econ. Geol., 2010, vol. 105, no. 3, pp. 669–688.
Nekrasov, I.Ya., Yakovlev, Ya.V., Solov’ev, L.I., and Leskova, N.V., First find of Au–Bi-sulfide, Dokl. Akad. Nauk SSSR, 1988, vol. 299, no. 2, pp. 438–441.
Pavlova, Z.N. and Kotel’nikov, P.E., Speciation of silver, bismuth, tellurium, selenium, cobalt, antimony in the copper–gold deposit of Kazakhstan, Izv. Akad. Nauk KazSSR, Ser. Geol., 1988, no. 2, pp. 13–23.
Pavlova, Z.N., Abulgazina, S.D., and Kotel’nikov, P.E., Sulfotellurides of bismuth from copper–gold deposit of northwestern Kazakhstan, Izv. AN RK, Ser. Geol., 1992a, no. 3, pp. 47–58.
Pavlova, Z.N., Levin, V.L., and Kotel’nikov. P.E., Gold and trace elements in the copper–gold deposit of the northwestern Kazakhstan, Izv. AN RK, Ser. Geol., 1992b, no. 5, pp. 55–67.
Pavlova, Z.N., Levin, V.L., and Tasov, B.M., New species of gold and bismuth in the copper–gold deposit of Kazakhstan, Izv. AN KazSSR, Ser. Geol., 1991, no. 3, pp. 63–68.
Sillitoe, R.H., The tops and bottoms of porphyry copper deposits, Econ. Geol., 1973, vol. 68, no. 6, pp. 799–815.
Zhukov, N.M., Infil’tratsionnyi metasomatizm i prirodnye kolonny gidrotermalitov (Infiltration Metasomatism and Natural Columns of Hydrothermalites), Alma-Ata, 1991.
Zhukov, N.M. and Filimonova, L.E., Prehnite–chalcopyrite ore association on the Aktogai copper–porphyry deposit, Izv. AN KazSSR, Ser. Geol., 1979, no. 6, pp. 53–55.
Zhukov, N.M. and Goikolova, T.V., Prehnite–chalcopyrite ore association as an indicator of deep formation of copper porphyry deposits, Izv. Akad. Nauk RK, Ser. Geol. Tekhn. Nauk, 2013, no. 3, pp. 43–45.
Zhukov, N.M., Pavlova, Z.N., Aubakirova, R.E., Kosterov, E.I., and Gachkevich, I.V., New combined type of gold mineralization, Izv. Akad. Nauk Kaz SSR, Ser. Geol., 1984, no. 5, pp. 1–5.
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We are grateful to the reviewers for comments and advice that made it possible to improve the content of the paper.
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The study was financially supported under the Program: “Scientific Support for Replenishment and Expansion of Mineral Resources in the Republic of Kazakhstan” (project no. BR05236638).
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Antonenko, A.A., Zhukov, N.M., Pavlova, Z.N. et al. The Varvarinskoye Complex Copper–Gold Deposit in Northern Kazakhstan: Mineral Types and Ore Composition. Geol. Ore Deposits 62, 314–331 (2020). https://doi.org/10.1134/S1075701520030022
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DOI: https://doi.org/10.1134/S1075701520030022