Makogon V. The lithology and paleogeography of the Visean deposits of the central part of the Dnieper-Donetsk basin (relation with oil and gas presence)

The work is concerned with study of the lithology-facies characteristics, peculiarities of diagenetic transformations, laws-dependences of the accumulation of sediments and of the paleogeography of the time of the formation of the Visean sedimentary rocks of the central part of the Dnieper-Donetsk basin. On the base of a lithogenetic study of core, the main facial types of the Visean deposits have that their spread on area and in section changed very much during the Visean time. A complex study of carbonaceous concretions has allowed to defined more precisely the character of diagenetic transformations. It has been determined that the facial conditions of the accumulation of sediments directly influenced the diagenesis environment and that this influence was reflected on the features of the chemistry-mineralogical composition of concretions. Siderite and pyrite geochemical facies were the conditions of the way of the diagenesis of clayey deposits. On the foundation of an analysis of lithology-paleogeographical maps drawn, the character and peculiarities of the paleogeography of the central part of DDB at the Visean time have been determined. It has been proved that, during the Visean time, an alternation of conditions of the accumulation of sediments, with the predominance of basinal sedimentation, took place. An estimation of the perspectives of the oil and gas presence of the Visean deposits has been carried out.