Geoheritage Resource of Small Mud Lakes in the Semi-Arid Environments of the Russian South

Lakes constitute a significant freshwater resource and are often regarded as being an important part of a country’s natural heritage. However, their geological heritage (geoheritage) value remains significantly understudied. Three small lakes, namely the Salt Lake, the Gruzskoe Lake and the Big Yashalta Lake, located in the central part of the Russian South were studied in this paper. The main focus of this research was to search for relevant unique geological features. This paper established that these lakes are distinguishable from other lakes by the presence of dark-colored mud that is rich in sulfides and methane. As a result of excessive summer evaporation, the lakes desiccate (partly or even fully) and this results in exposure of the mud as well as the formation of salt crystals and crusts. This bottom mud (peloid, therapeutic mud) forms as a result of highly-complex biogeochemical processes in semi-arid environments. This mud is interpreted as being part of the lake’s geoheritage as it belongs to sedimentary, geochemical and other types. Moreover, this geoheritage has a high ranking nationally. The most representative example can be found at the Big Yashalta Lake and for that reason, this lake is proposed as a geosite. Established sites of geoheritage importance are vital to geoscience research and geotourism activities and thus, these sites are considered to be a resource. Together with the development of local ecotourism and the use of peloids for the health industry purposes, the exploitation of this geoheritage resource would contribute to the sustainable development of the local area.