ABSTRACT
The knowledge of the problems of paleohydrogeology provides a principally new approach to understanding of the character of deep groundwater formation and accompanying oil-gas deposits. The methods of paleohydrogeological reconstruction are very different Conventional methods of investigation of the relationship of paleohydrogeological reconstruction, the role of variability of the thickness and quality of water-bearing and screen rock mass, discontinuity of sedimentation have been supplemented by the development of the analysis of continental drift, the water-rock balance, isotope of a wide range of elements. The retrospective review of the hydrogeological history evidences that the evolution of the underground hydrosphere is attributed primarily by its dynamics within fault zones which control the accumulation and discharge rate of groundwaters, specificity of their chemical composition as well as the oil and gas migration. At the old Siberian platform the stages of hydrogeodynamical activity existed in Proterozoic, Wend and Phanerozoic times. Paleohydrogeological reconstructions hypothesize that preservation of the oil and gas deposits are associated primarily with the presence of Mesozoic-Cenozoic centers of hydrogeodynamical activity. Among those are, for example, the oil-gas deposits in the fault zones along the rivers Vilui, Angara, Oka and Upper-Lena. The former hydrogeodynamical activity can be proved also by the presence of concentrated brines with high contents of hydrogen sulphide (1–2 g/dm3) in the productive series, as well as by the organic matter rich (Corg up to 30–40 mg/dm3) freshwater in suprasalt formations.
