Microfacies and Mineral Assemblages of Silver–Base-Metal Ores of the Maiminovskoe Vein Deposit (Sikhote-Alin, Dal’negorsky Ore District)

Abstract

The mineralogy of ore from the zones of extended trunk vein bodies and the local zones of veinlet-disseminated ores of the Maiminovskoe deposit is studied. A comparison is made at the level of mineral microfacies: hydrothermal filling of veins and veinlets and hydrothermal–metasomatic ores from altered sandstones in the selvages of the veins and veinlets. The identity of the mineral assemblages and the composition of the minerals from the microfacies of the studied zones is shown. An exception is the anomalously argentiferous chalcopyrite that is found only in the ores of the trunk veins. A common specific feature of the microfacies in the hydrothermal–metasomatic ores, which is expressed in enrichment of minerals formed during the replacement of sandstones by Co and Ni admixtures and in the presence of separate minerals Co, Ni, and Ti (cobaltite, ullmannite, and rutile), is revealed for the studied zones. It is shown that in terms of mineralogy and geochemistry, the vein ores of the Maiminovskoe deposit are similar to the ores from the upper (near-surface) parts of the ore bodies of the Ag–Pb–Zn skarn deposits in Dal’negorsky district.