Ore Mineralization of the Mutnovskoe Gold–Silver–Base Metal Deposit (Kamchatka)

The Mutnovskoe deposit is located in the southern part of the Central Kamchatka volcanic belt (Kamchatka Peninsula, Russia). The orebodies are concentrated within the submeridional Opredelyaushchaya vein zone, which occupies the central part of the Mutnovskoe ore field. According to the intensity of development of ore mineral assemblages, the vein zone is divided into northern, southern, and central parts, traditionally called flanks. The article presents the results of a mineralogical study of ore samples from the northern flank of the deposit, taken from core of boreholes drilled during the evaluation stage of geological exploration work. The data obtained in describing the typomorphic features of the main ore minerals are compared with the results of many years of research into the mineralogy of the southern flank. For the first time, hessite and minerals of the isomorphous series proustite–pyrargyrite, pirseite–polybasite were described in the ores of the northern flank. Differentiation of native gold fineness on the flanks of the deposit has been noted, which may evidence hidden mineralogical zoning of the products of the gold–silver stage of ore formation.