STRATIFYING OF THE PRE-JURASSIC FORMATIONS IN THE WESTERN UVATSKY DISTRICT OF THE TYUMEN REGION BASED ON A SET OF BIOSTRATIGRAPHIC, LITHOPETROGRAPHIC, AND SEISMIC DATA

D. A. Sidorov 1, T. B. Volchenkova 2, Ya. A. Vevel 2, A. V. Zhuravlev 3

1 Tyumen Petroleum Research Centre, Tyumen, Russia; 2 All-Russia Petroleum Research Exploration Institute, St. Petersburg, Russia; 3 Komi Geology Institute of the Research Centre of the Ural Branch of RAS, Syktyvkar, Russia

The paper provides the results of integrated stratigraphic studies of the pre-Jurassic section of the western Uvatsky District, including the analysis of data on biostratigraphy, lithostratigraphy, and seismic stratigraphy. The lithopetrographic composition of the pre-Jurassic basement rocks was characterised, indicating high heterogeneity. The latest results of dating the age of the Paleozoic deposits are given in the paper. The stratigraphic sequence of rock complexes of the basement and intermediate structural stage is justified. There are four structural formation complexes: Lower(?)-Middle Paleozoic volcanogenic-shale, the Upper Devonian – Lower Carboniferous terrigenous-carbonaceous, the Upper Paleozoic – Lower Triassic terrigenous-volcanogenic synoogenic, and the Middle-Upper Triassic terrigenous-volcanogenic syn-rift ones. The complexes identified were correlated with the units of the Regional Stratigraphic Chart of the Paleozoic of the West-Siberian Plane, dated 1999. The authors recommend updating of the current stratigraphic chart in relation of the straton correlation and dividing of the explored territory into zones.

Key words: stratification, pre-Jurassic basement, Paleozoic, Triassic, Uvatsky District, Western Siberia.

DOI 10.20403/2078-0575-2017-2-58-68

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