Ecological and Geographical Characteristics of the Lake Pelenkino (Rostov Region) Based on the Materials of Retrospective and Modern Research

The physical and geographical characteristics and geological structure of Lake Pelenkino are described. During the analysis of the results of the satellite survey, it was found that the area, length and width of the water surface of the reservoir, as well as the length of the lake's shoreline, the elongation index, and the compactness of the lake vary significantly both by year and by season. It has been suggested that the water surface area and the chemical composition of the water are influenced by both the amount of precipitation and wind-driven effects in the Sea of Azov. The chemical composition of water and mud solution is prone to accumulation of an equivalent amount of Mg2+ relative to Ca2+ over time, which may be due, along with the influence of a hydrological factor, to a change in the physical and chemical equilibrium in the water-mud system. According to the description of the well cores, deposits up to a depth of about 15-35 cm are represented by silt (mud), which first turns into steel-gray clay of a semi-liquid consistency, and then to the bottom of the layer into denser clay. The physical and chemical parameters of the mud of Lake Pelenkino allow us to classify them as continental, silt, mineral, medium mineralized, slightly alkaline, slightly sulfide peloids. Lithological control was found for a set of parameters (pH, Eh, CH4, Ssulfide), which manifests itself in their synchronous change during the transition from silts to the bedrock sediments of the reservoir bed – steel-gray clays. The content of gross mercury in the mud and sediments of the lake does not exceed the threshold of the Low range of Exposure (EQL), equal to 0.15 micrograms/g of dry weight. The bottom sediments of the rivers of the Pelenkino Lake basin and its mud themselves are under anthropogenic influence, which primarily forms a low level of perfringence titer values and its virulence. The use of lake mud for therapeutic purposes without prior preparation is not recommended.