Chrome spinels and accessory mineralization in the weathering crust of the Vladimir deposit, Varshavsky ultramafic massif, southern Urals

摘要

The paper presents the characteristics of chrome spinels from an ore-bearing packet of the Vladimir chromite deposit. Three main types of chrome spinels are distinguished by morphology and chemical composition: medium-chrome ore-forming, high-chrome transformed, and low-chrome relict accessory. The significant role of weathering conditions is expressed in alteration of accessory chrome spinel. The formation of high-chrome spinels is explained by the hydrothermal effect of the Varshavsky granitoid massif with accompanying dikes and talc-carbonate metasomatic rocks. Characteristic accessory minerals are represented by native gold and nickel, millerite, pentlandite, chalcopyrite, maucherite, PGE sulfides, and picroilmenite.