NATIVE GOLD TYPOMORPHISM AS INDICATOR OF VARIOUS TYPES OF MINERALIZATION OF LARGE SCARN-PORPHYRY Au-Fe-Cu DEPOSIT BYSTRINSKOE, EASTERN TRANSBAIKALIA
The paper makes up for the lack of publications on one of the main industrial components of the Bystrinskoye deposit - gold. The features of the distribution of native gold in ores, the frequency of gold formation in various matrix minerals, compositional variations, morphology and particle size distribution are established. It has been shown that the deposition of native gold is associated with all stages of the process of mineral formation: aposcarnic, porphyry and pyrite. The most informative typomorphic characteristic of native gold is composition: the dependence of fineness on the belonging of native gold to one or another part of the mineral formation process and partly on the depth of localization of gold mineralization is noted. The regularities of the enrichment of certain sections of ores with gold, rare for the deposit, were revealed. They are confined to zones of fracture and processing of primary ores during the application of late processes. A mineral indicator of gold enrichment is the coexistence of pyrite-chalcopyrite and magnetite aggregates, preferably in serpentinized aposcarns with minerals replacing them. Among them there may occur valeriitis, chalcopyrite and magnetite of subsequent generations (including W-magnetite), pyrite (especially Co-pyrite), sulfotellurides Bi, sulfides, sulfosalts, etc., which indicates the processing of primary concentrations of Au. The geochemical markers of gold-enriched ores - increasing contents of Mg, Cu, Co, Ag, Zn, W, Bi, Te, S, Pb, As, Sb, Hg in the ores - indicate the combination of all the processes that appear in the deposit that contribute to the concentration of Au.