ABSTRACT
The cupriferous sandstones and shales occur in rocks of a different metamorphic grade (from low-grade catagenesis to epidote-amphibolite facies of the metamorphism) and in rocks of variable age (from Upper Permian to Medium Proterozoic). Cupriferous sandstone and shale deposits are characterized by a follows series of common peculiar features: (1) the association with red-colored molasses, (2) the location of ore mineralization at the biogeochemical barrier; (3) ores are represented by Cu-S and Cu-Fe-S-type sulfides, nonstoichiometric minerals are widespread; (4) the uniform mineral zonation; and (5) ore mineralization controlled by the permeability of red-colored rocks. These regularities are explained by the migration of copper and other metals from the red parental ore formations and their precipitation in sulfide form at the biogeochemical barriers represented by organic-rich sediments. After their formation, cupriferous sandstone and shale deposits may have been subjected to metamorphic and supergene transformation that are reflected in the crystallochemical patterns of sulfide minerals, the paragenetic associations, mineral zonation, and ore body mineralogy.
