Mineralogy of host rocks of the Osinovskoe gold-quartz deposit (Central Urals)

Abstract

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.