Technogenic gold deposits of the Trans-Baikal Territory

Abstract

Relevance. The need to expand the mineral resource base of the Trans-Baikal Territory. Aim. To study the geochemical composition of technozems of tailings dumps of gold deposits of the Trans-Baikal Territory, their correspondence, in terms of gold content, to technogenic deposits, to calculate the exceeding the maximum permissible concentrations of toxic elements in technozems of tailings dumps. Objects. Technozems of tailings dumps of gold deposits of the Trans-Baikal Territory. Methods. Silicate, X-ray fluorescence ISP-AES methods in analytical laboratories of the Geological Institute of the SB RAS (Ulan-Ude) and JSC "SGS Vostok Limited" (Chita). Results. It was found that in terms of gold content (Au>0.4 g/t), the technozems of the tailings of the gold deposits of the Trans-Baikal Territory, in general, correspond to technogenic gold deposits. The largest volumes and contents of gold (1.2 g/t) are characterized by technozems of the Baleysky tailings dam deposits with insignificant gold contents are technozems of Darasunsky (0.36 g/t) and Kariysky (0.35 g/t) deposits. It is determined that the chemical composition of the technozems of the tailings depends on the composition of the host rocks developed in the areas of deposits. They correspond to the rocks of both basic and medium compositions. The distinctive features of the content of impurity elements in the technozems of tailings are due to the different compositions of the initial ores of gold deposits. These differences are reflected in the values of exceeding the maximum permissible concentrations relative to soils. Among the toxic elements, arsenic is characterized by maximum exceedances of the maximum permissible concentrations. In the technozems of the Lyubavinsky deposit, the excess of the maximum permissible concentrations of arsenic relative to the soil is 933 times, and the Baley deposit is 397 times.