ГЕОЛОГИЧЕСКАЯ ПОЗИЦИЯ, МИНЕРАЛЫ РЕДКИХ И БЛАГОРОДНЫХ МЕТАЛЛОВ В РУДАХ МЕДНО-НИКЕЛЕВОГО МЕСТОРОЖДЕНИЯ КУН-МАНЬЁ (ЮГО-ВОСТОЧНОЕ ОБРАМЛЕНИЕ СИБИРСКОЙ ПЛАТФОРМЫ)

Abstract

In this paper we present new data on geology of the Kun-Manie copper-nickel-PGE sulfide deposit of the Kun-Manie ore field located on the eastern periphery of the Pristanovoy orogen in the southeast of the Siberian Platform, as well as a detailed description of ores and basic minerals and the distribution of PGE mineralization in ores of the deposit. The ore bodies are spatially associated with sills of the Late Paleoproterozoic Kun-Manie gabbronorite-websterite-lherzolite complex of 1.76–1.69 Ga. It has been established that the outlines of disseminated Cu-Ni ores and ore-bearing sills of mafic-ultramafic rocks match almost exactly. Breccia and massive ores are confined to schists of the upper and lower parts of the ore shoots. Patchy disseminated and vein-disseminated mineralization is concentrated in zones of ductile deformation and along contacts between rock layers of different competence. The main ore minerals are pyrrhotite, pentlandite and chalcopyrite; less common are pyrite, marcasite, cubanite, bornite, chalcocite, sulfoarsenides (gersdorfite, glaucodot), arsenides (nicolite) and tellurides (melonite) of nickel. Magnetite and ilmenite occur in small amount. PGE mineralization is represented by arsenides (sperrylite), sulfoarsenides (irarsite, holingworthite), tellurides (Pd-melonite, merenskite, kotulskite), and tellurobismuthides (moncheite, michenerite). Arsenides, sulfoarsenides and tellurides of PGE, Ni, Ag and Bi, native gold and silver were found in vein-disseminated, patchy disseminated and breccia Cu-Ni ores. The concentration of a considerable part of the main sulfide minerals and the productivity of PGE mineralization are assumed to be due not only to complex processes of magmatic differentiation, but also to sulfurization of magma differentiates in zones of ductile (tectonic) deformation under the influence of recrystallized fluids. The productivity of PGE mineralization characteristically increases with increasing fluid concentrations of S, As, Te, Bi, and Sb.