Gold-sulphide mineralization and formation conditions of Sinilga deposit (Subpolar Urals)

S.K. Kuznetsova*, M.B. Tarbaevb, N.V. Sokerinaa**, T.P. Mayorovaa,c***, V.N. Filippova, S.N. Shaninaa****

aInstitute of Geology of the Komi Science Center, Ural Branch, Russian Academy of Sciences, Syktyvkar, 167982 Russia

bGeology and Licensing Office, Subsoil Management Department for the Northwestern Federal District in the Komi Republic (KOMINEDRA), Syktyvkar, 167982 Russia

cPitirim Sorokin Syktyvkar State University, Syktyvkar, 167005 Russia

E-mail: *kuznetsov@geo.komisc.ru, **sokerina@geo.komisc.ru, ***mayorova@geo.komisc.ru, ****shanina@geo.komisc.ru

Received January 22, 2018

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Abstract

Hydrothermal gold deposits are known in the Subpolar Urals, which are mainly associated with sulfide-quartz veins and zones of vein-disseminated sulfide mineralization. Their investigation is very important for the development of the existing ideas about the regional patterns of ore formation. We have studied the material composition and formation conditions of gold-sulfide ores from the Sinilga deposit. As a result of the study, we have established that the gold-sulfide mineralization of this deposit is superimposed on relatively young quartz veins filling the steeply dipping fractures oriented across the foliation of the rocks. Sulfides in the ores are mainly represented by coarse-grained galena, forming nests, veins and inclusions in vein quartz. Pyrite, pyrrhotite, arsenopyrite, and chalcopyrite are present in insignificant amounts. Hypergenic minerals are widely developed: goethite, hydrogoethite, anglesite, jarosite, cerussite, and scorodite. Gold is closely associated with sulfides, mainly with galena, which is often observed in areas of development of hypergenic minerals, in fractures of vein quartz, grows on small crystals of rock crystal. The composition of gold includes an admixture of silver (up to 10 wt. %). Crystallization of quartz of gold-bearing veins occurred in hydrothermal chloride-sodium-potassium solutions with a significant proportion of carbon dioxide in the temperature range from approximately 390 ?C to 270 ?C. Gold-sulfide mineralization corresponds to the latest stages of mineral formation. Sulfur of galena has a predominantly heavier isotopic composition (galena δ34S vary from +2.9? to +10? and are mainly in the range of 7.3–10?), indicating its primary sedimentary origin with a subordinate value of magmatic sources. We have suggested that hydrothermal processes played the most important role in the formation of the Sinilga deposit. They were conditioned by the Late Paleozoic metamorphism of the greenschist facies.

Keywords: gold, ore composition, sulfur isotopy, genesis, Sinilga ore occurrence, Subpolar Urals

Acknowledgments. The study was performed within the research and development project of the state task (SR no. AAAA-A17-117121270036-7) for the Institute of Geology of the Komi Science Center, Ural Branch, Russian Academy of Sciences and supported in part by the Ural Branch of the Russian Academy of Sciences (project no. 18-5-5-57).

Figure Captions

Fig. 1. Geological structure of the Sinilga gold deposit: 1 – quaternary deposits; 2. – upper and middle strata of the Middle Riphean Puyvinskaya series: dark gray. gray-green sericite-quartz. sericite-albite-quartz schists; 3 – granitoids of Narodinsk massif; 4 – faulting; 5 – gold-mining areas; 6, 7 – gold-sulphide-quartz veins and disintegrated sulphide-quartz veins; 8 – mining (ditches and trenches); 9 – outline of gold placer.

Fig. 2. Sulphides in the gold ore veins of the Sinilga deposit: a – galena partially substituted with anglesite in quartz; b – galena in pyrite; c – pyrite with a frame of iron hydroxides (grey); d – pyrrhotite in quartz; e – chalcopyrite and galena in pyrite; f – arsenopyrite partially substituted with scorodite in pyrite.

Fig. 3. Gold of the Sinilga deposit: a–e – gold in pyrite and products of supergene substitution of sulphides with secondary minerals; d – gold particle with an uneven distribution of impurities (areas with a high content of Ag are marked with dotted line); e – fragment of gold particle with complex shapes; f–h – gold in vein quartz.

References

  1. Tarbaev M.B. The vein type of gold mineralization in the Polar Urals. Extended Abstract of Cand. Geol.-Mineral. Sci. Diss. Syktyvkar, 1991. 16 p. (In Russian)
  2. Tarbaev M.B., Kuznetsov S.K. Sinilga gold occurrence in the Polar Urals. Syktyvkar. Mineral. Sb., 1996, no. 25, pp. 94–103. (In Russian)
  3. Tarbaev M.B., Kuznetsov S.K. Paleozoic gold veins in the Polar Urals. Dokl. Ross. Akad. Nauk, 1996, vol. 350, no. 5, pp. 658–660. (In Russian)
  4. Sokerina N.V., Shanina S.N., Zykin N.N., Isaenko S.I., Piskunova N.N. Conditions for formation of gold mineralization at the Sinilga gold occurrence, Polar Urals (According to the study of fluid inclusions). Zap. Ross. Mineral. O-va., 2013, vol. 142, no. 6, pp. 88–104. (In Russian)
  5. Fishman M.V., Yushkin N.P. Problems of metallogeny of European North-East. Seriya preprintov “Nauchnye doklady” [Ser. Preprints “Research Reports”]. Vol. 57. Syktyvkar, Komi Fil. Akad. Nauk SSSR, 1980. 29 p. (In Russian)
  6. Timonina R.G. Petrologiya metamorficheskikh porod Pripolyarnogo Urala [Petrology of Metamorphic Rocks in the Polar Urals]. Leningrad, Nauka, 1980. 102 p. (In Russian)
  7. Pystin A.M. Polimetamorficheskie kompleksy zapadnogo sklona Urala [Polymetamorphic Complexes of the Western Slope of the Urals]. St. Petersburg, 1994. 208 p. (In Russian)
  8. Bortnikov N.S., Bryzgalov I.A., Krivitskaya N.N., Prokof'ev Yu.V., Vikent'eva O.V. Multistage vein-disseminated gold-sulfide deposit Maiskoe (Chukotka, Russia): Mineralogy, fluid inclusions, stable isotopes, and formation conditions. Geol. Rudn. Mestorozhd., 2004, vol. 46, no. 6, pp. 475–509. (In Russian)
  9. Gibsher N.A., Tomilenko A.A., Sazonov A.M., Ryabukha M.A., Timkina A.L. The Gerfed gold deposit: Fluids and PT-conditions for quartz vein formation (Yenisei Ridge, Russia). Russ. Geol. Geophys., 2011. vol. 52, pp. 1461–1473.
  10. Grinenko V.A. Preparation of sulfur dioxide for isotope analysis. Zh. Neorg. Khim., 1962, no. 7, pp. 2578–2582. (In Russian)
  11. Mayorova T.P. Isotopy of sulfur and lead of sulphides from gold deposits in the Northern Urals. Geologiya i mineral'nye resursy evropeiskogo severo-vostoka Rossii: Materialy XV geol. s”ezda Respubliki Komi [Geology and Mineral Resources of the European North-East of Russia: Proc. XV Geol. Congr. of Komi Republic]. Vol. II. Syktyvkar, IG Komi NTs Ural. Otd. Ross. Akad. Nauk, 2009, pp. 274–276. (In Russian)
  12. Chang Zh., Large R., Maslennikov V. Sulfur isotopes in sediment-hosted orogenic gold deposits: Evidence for an early timing and a seawater sulfur source. Geology, 2008, vol. 36, no. 12, pp. 971–974. doi: 10.1130/G25001A.1.
  13. Dubinina E.O., Ikonnikova T.A., Chugaev A.V. Isotopic variations of sulfur from the Sukhoi Log deposit. XIX simpozium po geokhimii stabil'nykh izotopov im. akad. A.P. Vinogradova [Proc. XIX Symp. on Geochemistry of Stable Isotopes Named for Acad. A.P. Vinogradov]. Moscow,  Akvarel', 2010, pp. 102–106. (In Russian)
  14. Michurin S.V., Krupenin M.T., Sharipova A.A. Sulfur isotopic composition of sulphides from the Riphean deposits in the western slope of the Southern Urals. XIX simpozium po geokhimii stabil'nykh izotopov im. akad. A.P. Vinogradova [Proc. XIX Symp. on Geochemistry of Stable Isotopes Named for Acad. A.P. Vinogradov]. Moscow, Akvarel', 2010, pp. 251–254. (In Russian)
  15. Goldfarb R.J., Baker T., Dubé D., Groves D.I., Craig J.R. Hart C.J., Patrice Gosselin P. Distribution, character, and genesis of gold deposits in metamorphic terranes. In: Economic Geology 100th Anniversary Volume. Soc. Ekon. Geol., Inc., 2005, pp. 407–450.
  16. Goryachev N.A. Proiskhozhdenie zoloto-kvartsevykh zhil'nykh poyasov severnoi Patsifiki [The Origin of Gold-Quartz Vein Zones of the North Pacific]. Magadan, SVKNII Dal'nevost. Otd. Ross. Akad. Nauk, 2003. 143 p. (In Russian)
  17. Omoto H., Ray R.O. Isotopes of sulfur and carbon. In: Geokhimiya gidrotermal'nykh rudnykh mestorozhdenii [Geochemistry of Hydrothermal Ore Deposits]. Moscow, Mir, 1982, pp. 403–450. (In Russian)
  18. Karyakin A.E., Smirnova V.A. Struktury khrustalenosnykh polei [Structures of Crystal-Bearing Fields]. Moscow, Nedra, 1967. 240 p. (In Russian)
  19. Bukanov V.V. Gornyi khrustal' Pripolyarnogo Urala [Rock Crystals of the Polar Urals]. Leningrad, Nauka, 1974. 212 p. (In Russian)
  20. 20.{cke_protected}{C}%3C!%2D%2D%20%20value%3D%2221%22%2D%2D%3E-->Kuznetsov S.K. Zhil'nyi kvarts Pripolyarnogo Urala [Vein Quartz of the Polar Urals]. St. Petersburg, Nauka, 1998. 203 p. (In Russian)
  21. Ogorodnikov V.N., Sazonov V.N. Sootnoshenie zolotorudnykh i khrustalenosnykh mestorozhdenii obramleniya gneisovykh blokov Urala [The Ratio of Gold and Rock Crystal Deposits Framing Gneiss Blocks of the Urals]. Sverdlovsk, Ural. Otd. Akad. Nauk SSSR, 1991. 72 p. (In Russian)
  22. Vodolazskaya V.P., Berlyand N.G., Kotov K.N., Shergina Yu.P., Mareichev A.M., Akimov L.V. Kozhimskaya area of tectonic and magmatic activity and its gold bearing potential. Rudy Met., 1996, no. 4, pp. 16–27. (In Russian)


For citation: Kuznetsov S.K., Tarbaev M.B., Sokerina N.V., Mayorova T.P., Filippov V.N., Shanina S.N. Gold-sulphide mineralization and formation conditions of Sinilga deposit (Subpolar Urals). Uchenye Zapiski Kazanskogo Universiteta. Seriya Estestvennye Nauki, 2018, vol. 160, no. 2, pp. 308–323. (In Russian)


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