Types of karst and features of its distribution in the Southern Urals and in the Cis-Urals
The karst process is the result of a long natural-historical process of formation of the geological environment. The lithological composition of karst rocks predetermined the greatest impact on the territory by surface karst occurrences in the areas of sulphate karst development in the Southern Cis-Urals, and in the Southern Urals the highest concentration of karst caves in conditions of carbonate karst development. At the same time, the history of the geological development of the region in recent times has led to the maximum occurrence of ancient karst caves and buried karst forms in the Southern Urals in comparison with the Southern Cis-Urals. The history of relief formation in the Neogene-Quaternary time largely predetermined the degree and nature of overlap of karst rocks by non-karst, significantly determining the intensity of the distribution of karst manifestations and the modern activity of sinkhole formation. The limiting thicknesses of the sediments covering karst rocks, at which the karst appears on the surface, have been established. Of particular danger are karst and suffosion-karst processes in gypsum, leading to the formation of karst sinkholes and, as a result, to deformation of residential and industrial facilities. Karst significantly intensifies human economic activity, which radically changes the hydrogeodynamic and hydrogeochemical situation in the karst-affected rocks as well as in the upper and lower strata.