Klimchuk O. Hypogene speleogenesis, its hydrogeological importance and role in the evolution of the karst

Thesis deals with the two related scientific problems: 1) improvement of the theoretical and methodological foundations of karst studies, 2) identification of regularities of hypogene speleogenesis and of its place and role in the evolution of karst. Hydrogeological approach to the definition of karst is adopted, in which karst is viewed as a groundwater circulation geosystem with specific properties, determined by speleogenetic self-organization of permeability structure and flow pattern. Such self-organization is a system-forming property of karst, and thus speleogenesis is the central process in the formation of karst and evolution of karst aquifers. It is shown that main differences in the origin and structural and functional characteristics of karst conduit-void systems (types of speleogenesis) are determined by hydrodynamic properties of confined and unconfined circulation systems. Hypogene speleogenesis is connected with upwelling segments of confined circulation systems in heterogeneous strata. Peculiar features of the mechanism of hypogene speleogenesis are revealed, its structural, functional and morphological features are identified, and structures of hypogene conduit-void systems are classified. Regional regularities of hypogene speleogenesis are revealed, hydrogeological settings of its development are typified. Criteria for identification of hypogene speleogenesis are elaborated and methodology of speleogenetic analysis is improved. The significant role of hypogene speleogenesis in the formation of deposits of hydrocarbons and hydrogenic ores in soluble and adjacent strata is demonstrated, as well as its role in the origin and development of hazardous geological processes. An evolutionary-genetic approach is elaborated to the typology of karst and prediction of karst-related hazards and mineral resources. Hypogene karst has wider global distribution than the "traditional" epigene karst. The territory of Ukraine is characterized by predominance of active and relict hypogene karst.