Modern mineral formation in the geotechnogenic landscape of the Sherlovogorsky ore area (Eastern Transbaikalia)

Mineralogical and geochemical features of 15 deposits of various ore formations and the corresponding natural and ge-otechnogenic landscapes of the mining areas of Transbaikalia are studied. The inheritance of the chemical composition of mined ores and their waste was established. The fields under development have been and remain sources of certain typochemical associations of chemical elements forming their toxicogenic concentrations in varying wastes. The contents of most chemical elements (Cu, Zn, Cd, Pb, Bi, Sb, W, Sn, Ce, Mo, Sn) in the technozems of geotechnogenic landscapes significantly exceed the clarke and MPC for soils. Of the chemical elements whose high concentrations represent an environmental hazard, As, Pb, Zn, Sb, Cd and Bi are the most common in the studied landscapes. Depending on their concentrations in the technozems exceeding the MPC and APC, and the contents of the main minerals and chemical elements of the ores, mineralogical and geochemical typification of the studied geosystems was performed. Two of their main groups were identified: arsenic and armpitic. The first are geosystems with arsenic content in mining waste of 300 g/t and more. To the second with its smaller contents, geotechnogenic landscapes from the tunisten deposit of greisen formation and molybdenum. The arsenic type includes geosystems with deposits of gold-quartz formation, arsenic-antimony with deposits of a shallow gold-silver formation and gold-sulfide-quartz in granitoids. Arsenic-bismuth and arsenic-antimony-bismuth types are also associated with deposits of gold-sulfide-quartz formation. Arsenic-antimony-molybdenum in granitoids with extremely minimal arsenic content; arsenic-polymetallic type, associated with deposits of polymetallic, tin-polymetallic and gold-polymetallic formations. This type is characterized by a wide range of toxic elements and their high concentrations in mining waste with a predominance of antimony or bismuth, depending on the geochemical specialization of the field, as well as the constant presence of cadmium over 2 g/t, exceeding the APC. Antimony is widespread in the mining wastes of polymetallic and gold ore deposits, with the exception of those enriched with bismuth. Bismuth forms environmentally hazardous contents in the products of processing of tungsten, tin-polymetallic, gold-quartz-molybdenum, gold-sulfide-quartz formations. Lead is a cross-cutting product for the processing of deposits from all polymetallic formations. The most dangerous cadmium is typical for all formations, except gold and molybdenum. It's minimum, albeit dangerous concentrations are typical for geotechnogenic landscapes of molybdenum and gold-molybdenum ore formations. It is shown that the associations of chemical elements in technozems depend not only on their ore-formational affiliation, but also on the technology of processing ore deposits.

Keywords

Authors

References