Regional stratigraphic subdivisions of the Paleozoic of the West-Siberian plate

The given regional stratigraphic model accountsfor the published information and for the new data of the author on Latitude Priob'ye, Novoportovsky zone, and the southeast of theWest-Siberian plate (WSP). The structural-facial division into districts of the Palaeozoic is used, which the author, together with V.S.Bochkarev, developed in the early 1990s. The International Stratigraphic Committee approved the majority of the aboriginal subdivisionsof WSP in 1999, except the Tyumen, Uvatsky, Ishimsky and Shaimsky areas where, despite single stratigraphic units with namesand parametric wells, stratigraphic works were not conducted. The scheme of comparison lacks the recent data on Pre-Yenisei region ofthe Chulym-Yenisei structural-facial zone (boring wells: Vostok-1, 3, 4, Tyisky, Lemok). The anhydrites, the continuous differentiatedsectional view of the Cambrian period in the pre-Jurassic complex of rocks, the geochemical specificity of the organic matter allow assumingthe territorial independence of this region and considering it as belonging to the Siberian platform, rather than to WSP. The authorincludes a new Novomostovskaya stratum representing a complex of reef formations of the Visean in the lithostratigraphic frame ofthe Sherkalinsky structural-facial zone (SFZ). In the article 12 stratigraphic units of various statuses are described: the Pavlovsky andLarinsky layers of the Upper Ordovician and the Lower Silurian, the Ostaninsky layers of the Upper Silurian and the horizons of theDevonian system - Kyshchtovsky, Armichevsky, Solonovsky, Biasinsky, Elley-Igaysky, Gerasimovsky, and Luginetsky. The Luginetsky,Tamyrsatsky and East-Nikolsky "horizons" are not regional stratigraphic subdivisions according to the requirements of the StratigraphicCode of Russia (2006) due to the absence of regional types-indices (by different groups of organisms) and insufficient paleontologicallyreasonable borders. The horizons established on the biostratigraphic basis and laterally embracing a province or a paleobiogeographicrange can be named regiolayers according to the Code. The author also uses the term "parasedia" meaning paragenetic "associationof rock bodies formed from simultaneously deposited sediments". That is, the definition contains the idea of synchronism ofcreation of the rock bodies bound by paragenesis at the stage of sedimentation. The author uses the concept "parasedia" for synchronisationof rock bodies (suites, layers) from different SFZ of the West-Siberian plate for understanding the dynamics of developing and evolutionof WSP as a unified independent tectonic segment of a lithosphere (paraplatform). The frame of the Pre-Jurassic basis of WSP hasthree levels: pre-paraplatform (R-O2) - marine regime; paraplatform (O3-C2) - marine regime; taphrogen (C2-T) - continental regime. Inthe first level there are two regiolayers, in the second and third levels - three regiolayers. Each level has syneclise, aulacogen and destructivestages of development. Each stage of the paraplatform development starts with the stage of stabilising, levelling of the reliefand developing of residual soil and ends with the maximum bowing, diversification of magmatism, arched uplift of all the territory ofWSP.

Keywords

Authors

References