Time-Lapse Electrical Resistivity Tomography and Soil-Gas Measurements on Abandoned Mine Tailings Under a Highly Continental Climate, Western Siberia, Russia

Abstract

Mine tailings are a very active system in which the processes of oxidation, dissolution, and the re-deposition of substances occur in real-time. Time-lapse electrical resistivity tomography and soil-gas measurements have been used on abandoned mine tailings under a highly continental climate, Western Siberia, Russia. The electrical resistivity tomography method allows the structure of the tailings to be determined, namely, its electrophysical parameters, which are related to the chemical composition and geochemical characteristics of the subsurface substance. The aim of this work is to determine the variations in the geoelectrical zoning of sulfide-bearing mine tailings depending on fluctuations in environmental conditions, i.e., ground and air temperature, in conjunction with volatile compounds of environmental concern emanating from the tailings (SO2, CS2, C2H6S). The hourly observations revealed that the configuration of the geoelectrical section varies during the day. The concentration of gases in the surface air layer varied in accordance with the ambient temperature conditions. In general, the minimum gas concentrations were determined at night, and the increase in gas concentrations began when the temperature increased. The dependence of gas formation on temperature conditions differed during the daytime and nighttime. In warmer hours, gas concentrations are highest. At night, when there was a decrease in the temperature of air and then in the ground temperature, a local increase in the concentration of all measured gases occurred at the maximum temperature difference in the air (14.1 °C), and the ground remained relatively warm (20.8 °C). There is a close relationship between ground temperature, electrical resistivity, and the rate of gas production. Local anomalies with the greatest variation in electrical resistivity are associated with the zones that have the most active gas emanations.