A twenty-year break in the development of official stratigraphy made possible a complete inspection of the state of stratigraphic research in Western Siberia and identification of stratigraphic levels with minimum certainty in existing ideas, requiring a complete reinterpreting, as well as levels requiring some degree of further detailing and updating. A review of stratigraphic data demonstrated that the most considerable changes are required in the Regional Triassic Stratigraphy Scheme that is based on the incorrect understanding of rifting (its absence) in the Western Siberian north. It is found that in the most of West Siberian regions (and first of all in the eastern slope of the Subpolar Urals) Triassic sedimentary formations previously identified using the improper principles of dating of palynological complexes must be assigned to Lower-Middle Jurassic. The position of Jurassic-Triassic interface is updated in the columns of ultradeep СГ-6 and СГ-7, and Gydanskaya-130 wells. The authors note the need for fundamental changes in the regional stratigraphic scheme of West Siberian Triassic and Lower-Middle Jurassic series.

Aleksei A. Nezhdanov  ORCiD
Doctor of Geological and Mineralogical Sciences
ZapSibNIIGG,
48/4a, ul. Respubliki, Tyumen, 625000, Russia
e-mail: nezhdanovaa@zsniigg.ru
SPIN-код: 4650-3952
Author ID: 165305

​Valerii V. Ogibenin 
Scientific Adviser
ZapSibNIIGG,
48/4a, ul. Respubliki, Tyumen, 625000, Russia
e-mail: OgibeninVV@zsniigg.ru
SPIN-код: 5551-8234
Author ID: 985783

Evgeniya A. Slutsker
Leading Geologist
ZapSibNIIGG,
48/4a, ul. Respubliki, Tyumen, 625000, Russia
e-mail: SlutskerEA@zsniigg.ru

​Aleksei V. Trigub
Head of Division
ZapSibNIIGG,
48/4a, ul. Respubliki, Tyumen, 625000, Russia
e-mail: TrigubAV@zsniigg.ru
SPIN-код: 9769-0829
Author ID: 1019091

Evgenii N. Khomitskii
Head of Department
ZapSibNIIGG,
48/4a, ul. Respubliki, Tyumen, 625000, Russia
e-mail: TrigubAV@zsniigg.ru

​Ekaterina A. Kitlyain
Leading Geophysicist
ZapSibNIIGG,
48/4a, ul. Respubliki, Tyumen, 625000, Russia
e-mail: KitlyainEV@zsniigg.ru

Artem R. Novikov
1^st category Geologist
ZapSibNIIGG,
48/4a, ul. Respubliki, Tyumen, 625000, Russia
e-mail: novikovar@zsniigg.ru

​

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