Mineralogy and formation conditions of the Yuzhno-Magnetitovoye gold-polymetallic deposit (Ozerninsky ore cluster, Republic of Buryatia)

The Yuzhno-Magnetitovoye deposit is located in the Eravninsky district of the Republic of Buryatia and localized in a sequence of volcanosedimentary rocks and is confined to a mineralized zone of crushing and brecciation near syenite and dolerite dikes, where vein-veinlet quartz and disseminated sulfide mineralization is developed and lens-shaped bodies of magnetite ores are present. Secondary metasomatic alterations, including propylitization, argillization, and silicification are developed, as well as skarns revealed at deeper levels. Approximately 30 mineral species were identified in the ores, the principal ones being magnetite, hematite, chalcopyrite, and pyrite. The minerals of the oxidation zone are cuprite, covellite, idaite, iron hydroxides, and native copper.Based on ore composition studies and mineral geothermometry, it has been established that the Yuzhno-Magnetitovoye deposit formed in three stages: the skarn, hydrothermal-metasomatic, and supergene ones. The geological features, mineral composition of the ores, and the isotopic and geochemical characteristics of the Yuzhno-Magnetitovoye deposit allow us to assine it to the gold-skarn type.