The Tukulan Section in the Baibykan River Area as a New Type of Jurassic Marine Deposits in the Vilyui Syneclise and Preverkhoyansk Foredeep

Grinenko V.S., Knyazev V.G.

It is established that part of the Lower – Middle Jurassic lithological section is missing in closed areas in the eastern Siberian platform, in the buried Laptev subcoplex (T3r2–J3v) of the Verkhoyansk terrigenous complex (C1v–K1al1). These areas are restricted to the latitudinal segment of the Preverkhoyansk foredeep. In the sedimentary cover of the foredeep, in marine facies, we studied and traced (from natural exposures and deep core holes) a stratigraphic gap genetically related to the dropping of the regional clayey marker, the Suntar Formation, out of the continuous terrigenous sedimentogenesis of the Vilyui syneclise. A comparison of the established structure of the section and the well-known types of stratigraphic section in the Vilyui syneclise and the Preverkhoyansk foredeep (Suntar, Mastakh, Zhigansk, Khapchagay, Ust’-Vilyui and Aldan) necessitates putting into use of a new «Tukulan» type of section for the Lower – Middle Jurassic marine deposits. The age and stratigraphic volume of the Tukulan-type section were correlated with the International and regional stratigraphic scales. Analysis of paleomagnetic remains in local geologic bodies of this new type of section as well as correlation of their vertical sequence with sections of meridional and latitudinal segments of the Preverkhoyansk foredeep (Lena and Aldan RR. basins) confirm the need for using this new type of section for structures in the eastern Siberian platform such as the Lungkha – Kelya basin, the Tukulan protrusion and the Yakutian buried arched uplift. The foregoing shows that usage of this new type of section with its paleontological characteristics in exploration work in closed areas of the ancient Siberian platform will provide best substantiation for extending the radius of action of regional horizons (Zimniy  through Malyshev) established in Siberia into the western periphery of the East Siberian structural-facies area.

Key words: Siberian platform, Vilyui syneclise, Preverkhoyansk foredeep, East Siberian structural-facies area, regional horizons, Verkhoyansk terrigenous complex, Laptev subcomlex, series, formation.

Science and Education, 2017, No.3, pp.21-29