The paper describes the mineralogy of mica shales of the Osinovskoe gold deposit in the Central Urals. Our studies unraveled the role of dynamometamorphism in the transformation of primary rocks and allowed the characterization of their metasomatic alteration. We showed the relationship between plastic and brittle deformations and the formation of gold-bearing mineral assemblage with major pyrite, pyrrhotite and ilmenite and subordinate and rare sphalerite, chalcopyrite, marcasite, rutile, magnetite, molybdenum, galena, altaite, hessite, melonite, petzite, calaverite, volynskite, and sylvanite. The Ag content of native gold varies from 4 to 29 wt. %. Tellurides are associated with pyrite and pyrrhotite and also form monomineral grains and intergrowths in chlorite and mica with inclusions of REE minerals (xenotime-(Y), monazite-(Ce), hydroxylbastnesite-(Ce)), allanite-(Ce)), REE-bearing minerals (epidote, apatite, zircon), Th silicate (torite), and uraninite.

Keywords: REE minerals, xenotime, monazite, hydroxylbastnesite, tellurides, native gold, sulfdes, mica shales, metamorphism, gold deposit, Central Urals.

Received 07.10.2023, accepted 04.12.2023

N.P. Safina, South Urals Federal Research Center of Mineralogy and Geoecology UB RAS, Institute of Mineralogy, Miass, Chelyabinsk district, 456317 Russia; natali-safna2015@yandex.ru

L.Ya. Kabanova, South Urals Federal Research Center of Mineralogy and Geoecology UB RAS, Institute of Mineralogy, Miass, Chelyabinsk district, 456317 Russia; 

I.A. Blinov, South Urals Federal Research Center of Mineralogy and Geoecology UB RAS, Institute of Mineralogy, Miass, Chelyabinsk district, 456317 Russia

1. Ayupova N.R., Maslennikov V.V., Filippova K.A.(2019) REE geochemistry and mineralogy in ores of the Talgan Cu-Zn massive sulfde deposit, Southern Urals. Doklady Earth Sciences, 487, 973–975.
2. Belogub, E.V., Novoselov, K.A., Shilovskikh, V.V., Blinov, I.A., Palenova, E.E. (2022) Rare-earth elements and Th minerals in the metasandstones of the Udokan Basin (Russia). Geology of Ore Deposits, 64(7), 125–140.
3. Buslaev F.P., Marx V.A., Prakhova E.V. (1988) [Mauk deposit] In: Mednokolchedannye mestorozhdeniya Urala:Geologicheskoe stroenie [Massive sulfde deposits of the Urals: Geological structure]. Sverdlovsk, UNTs AN USSR, 164–171. (in Russian)
4. Eliseev N.A. (1959) [Metamorphism]. Moscow, MGU, 415 p. (in Russian)
5. Flynn D. (1967) [Deformations under metamorphism]. In: Priroda metamorphizma [The Nature of Metamorphism]. Moscow, Mir, 49–78. (in Russian)
6. Giere R., Sorensen S.S. (2004) Allanite and other REE-rich epidote-group minerals. Reviews in Mineralogy & Geochemistry, 56, 431–493.
7. Gramenitsky E.N. (2012) [Petrology of metasomatic rocks]. Moscow, INFRA-M, 221 p. (in Russian)
8. Kirmasov A.B. (2011) [Basics of structural analysis]. Moscow, Nauchny mir, 368 p. (in Russian)
9. Korovko A.V., Dvoeglazov D.A., Kuzovkov G.N. et al. (2015) [State Geological Map of the Russian Federation. Scale 1 : 200000. Second edition. Central Urals Series. Sheet O-41-XXXII. Explanatory note]. Moscow, VSEGEI, 274 p. (in Russian)
10. Marakushev A.A., Bobrov A.V. (2005) [Metamorphic petrology]. Moscow, Nauka, 256 p. (in Russian)
11. Marx V.A. (1969) [Metamorphism of albite-epidote-amphibolite facies of rocks of the greenstone zone in the Verkhny Ufaley district in the Central Urals]. In: Metamorphizm gornykh porod glavnoy vulkanogennoy zony Urala [Metamorphism of Rocks of the Main Volcanic Zone of the Urals]. Moscow, Nauka, 120–207. (in Russian)
12. Melekestseva I.Yu. (2007) [Heterogeneous Co-bearing massive sulfde deposits in ultramafc rocks of paleoisland-arc structures]. Moscow, Nauka, 245 p. (in Russian)
13. Nicolas A. (1992) [Basics of rock deformations]. Moscow, Mir, 167 p. (in Russian)
14. Novoselov K., Belogub E., Shilovskikh V., Blinov I., Filippova K. (2023) Origin of ironstones of the Udokan Cu deposit (Siberia, Russia): A key study using SEM and LA-ICP-MS. Journal of Geochemical Exploration, 249, 107–221.
15. Palenova E.E., Rozhkova E.A., Belogub E.V., Rassomakhin M.A. (2022) [REE minerals in black shales of the Paleoproterozoic Mikhailovka Formation (Baikal-Patom Highland, Siberia)]. Mineralogiya [Mineralogy], 8(3), 47–66. (in Russian)
16. Safna N.P., Maslennikov V.V., Maslennikova S.P., Glushkov A.N. (2010) [Mineralogical and geochemical features of sulfde ores of the Zapadnoye ore occurrence, Subpolar Urals]. Materialy of XIII nauchno-prakticheskoy konferentsii “Puti realizatsii neftegazovogo i rudnogo potentsiala KHMAO-Yugry” [“Materials of the XIII Scientifc-Practical Conference Ways to Implement the Petroleum and Ore Potential of KhMAO-Ugra“], Khanty-Mansiysk, 492–501. (in Russian)
17. Safna N.P., Maslennikov V.V., Maslennikova S.P., Kotlyarov V.A., Danyushevsky L.V., Large R.R., Blinov I.A. (2015) Banded sulfde-magnetite ores of Mauk copper massive sulfde deposit, Central Urals: composition and genesis. Geology of Ore Deposits, 57, 191–212.
18. Safna N.P., Kabanova L.Ya., Kuznetsov D.A., Blinov I.A. (2015) [Metamorphosed sulfde ores of the Luchistoye Cu occurrence, South Urals]. Mineralogiya [Mineralogy], (4), 79–90. (in Russian)
19. Serdyuchenko D.P., Lutz B.G., Mineev D.A., Kochetkov O.S., Pavlov V.A. (1967) [Rare elements in rocks of various metamorphic facies]. Moscow, Nauka, 199 p. (in Russian)
20. Shepel E.V., Ayupova N.R., Rassomakhin M.A., Khvorov P.V. (2021) [Thorium, uranium and rare-earth mineralization of the Ugakhan gold deposit, Bodaibo ore region]. Mineralogiya [Mineralogy], 7(3), 78–93. (in Russian)
21. Soroka E.I., Pritchin M.E., Leonova L.V., Bulatov V.A. (2022) Rare-earth fuorocarbonates in rocks of the Saf’yanovka Cu–Zn massive sulfde deposit, Middle Urals. Doklady Earth Sciences, 507, S262–S268.
22. Vedernikov V.V., Dvoeglazov D.A. (1997) [Unpublished report on advanced geophysical and geochemical works and additional geological exploration on a scale of 1 : 50 000 with a general search for gold and copper within the Sosnovskaya area (topographic sheets O-41-123-A, B, C, D and O-41-135-A) for 1987–1995)]. Verkhnyaya Pyshma, 1474 p. (in Russian)
23. Vernon R.H. (1980) [Metamorphic processes]. Moscow, Nedra, 226 p. (in Russian)
24. Yarosh P.Ya. (1973) [Diagenesis and metamorphism of sulfde ores in the Urals]. Moscow, Nauka, 240 p. (in Russian)