Structure of the South Urals and cis-Uralian foredeep as revealed by interpretation of regional seismic data and the origin of the prolific of oil reserves in the Volga Urals Basin
Ключевые слова: South Urals; cis-Uralian foredeep; Volga Urals Basin; thrust belt; oil; gas; seismic surveying; Riphean-Vendian deposits; Domanik source rock; Romashkino oil field.
Для цитирования: Sobornov K.O. Structure of the South Urals and cis-Uralian foredeep as revealed by interpretation of regional seismic data and the origin of the prolific of oil reserves in the Volga Urals Basin. Geologiya nefti i gaza. 2023;(1):7–25. DOI: 10.31087/0016-7894-2023-1-7-25. In Russ.
Acknowledgments: The author expresses his deep gratitude to A.W. Bally, V.A. Baldin, D. Gee, J. Knapp, I.P. Korotkov, N.K. Fortunatova, V.E. Khain, V.S. Shein for fruitful discussions concerning various aspects of seismic interpretation, geology, and oil and gas potential of the Southern Urals and the Cis-Urals.
Interpretation of the regional seismic data in the South Urals and cis-Uralian foredeep suggests that the eastern flank of the East European Platform has passed through two cycles of continental margin basin’ development. One took place in the Riphean-Vendian (Late Precambrian), second- in the Paleozoic. Each of them ended up with continental collision and folding. The Paleozoic structuring overprinted the Riphean-Vendian section. It produced disharmonic structure of the Cis-Uralian sedimentary cover and overlapping of the two continental margin’ megasequences. The proposed geological interpretation suggests that the prolific Paleozoic deposits of the central part of the Volga Ural Basin were the focus of oil migration from the nearby buried multikilometer-thick Riphean-Vendian section of the cis-Uralian Foredeep. The contribution of the predominantly immature Domanik source rock was of secondary importance in hydrocarbon charging. This proposition provides solution for the lasting debate concerning the origin of the unique petroleum endowment of the Volga Ural Basin.