On the Genesis of the Kargala Copper Sandstones

The article considers the main features of formation and the nature of the location of copper sandstones in the southern part of the western Urals strip of about 600 km length. Kargalin copper ores on the Sakmarsko-Dmitrievskaya mineralization area, represented by malachite and azurite, as well as cuprite, native copper, and related minerals, were formed in the red-brown sandstone sediments in the form of separate lenses, nests, interlayers in the channels of ancient rivers flowing from the Ural Mountains in Late Permian (Kazanian and Tatarian epochs) 230-285 million years ago. The indigenous deposits of the Ural Mountains, washed away by rivers were the sources of sulfide solutions. Accumulations of terrestrial vegetation and other organic matter in riverbeds served as precipitators of copper from solutions. Mineral deposits repeat the shape of river meanders and are distributed extremely unevenly across the Kargalinskiy ore field, repeatedly overlapping in more than hundred meters thick sedimentary rocks. Formation of coppery sandstones in the Urals occurred at the syngenetic geochemical barrier along Kungurian salt anticlines and salt diapirs. The barrier is indicated by a sharp flexural dipping of the Artinskian deposits towards the foothill trough with the overlaying salt anticlines.