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CONDITIONS OF FORMATION OF THE BAZHENOV FORMATION SECTIONS WITHIN THE MALYY BALYK DOME-SHAPED UPLIFT

R. M. Saitov, M. A. Fomin

A. A. Trofimuk Institute of Petroleum Geology and Geophysics SB RAS, Novosibirsk, Russia

Based on the study of lithological composition of rocks, as well as structural and paleostructural analysis within the Malyy Balyk dome-shaped uplift, conditions for generation of the Bazhenov Formation are analyzed and restored. It was revealed that sedimentation rates of the Bazhenov Formation were unstable and varied over the time. The main changes in sedimentation rates are associated with the bioproductivity of radiolarias, while non-skeletal organisms did not significantly affect the accumulation of organic matter. It is assumed that a sharp decrease in the productivity of living organisms at the end of the Middle Volgian, which existed in the West Siberian Sea, could be due to the influence of volcanic activity. The bottom paleorelief in the Late Jurassic – Early Cretaceous influenced the processes of sedimentation within the studied territory, which is reflected in the difference in thicknesses of the Bazhenov Formation, isolated members and their lithological composition, their lithological composition and reservoir properties.

Keywords: Bazhenov Formation, paleogeography, conditions of formation, section types.

DOI 10.20403/2078-0575-2024-1-45-56

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