Geological Structure of the Basement of Western and Eastern Parts of the West-Siberian Plain

The U-Pb dating (SHRIMP-II on zircon) was obtained for the first time from the basement of the West Siberian Plain in the Western half of the region. It is established that a large part of the protolith of the metamorphic depth in the Shaim-Kuznetsov meganticlinorium contained sedimentary late- and middle-Devonian rocks (395-358 million years). Probably, greywackes served as a substrate of metamorphic rocks substrate, which were formed largely in the erosion of ophiolitic association rocks. The U-Pb method helped to specify late carbonic age of granite plutons composing the Shaim-Kuznetsov meganticlinorium. It turns out that the kernels of anticlinoria are not Precambrian blocks, but Paleozoic magmatic and metamorphic complexes, i.e., the formations of the lower and middle part of the crust. In the Eastern part of Western Siberia, the tectonic zoning of the basement of East Khanty-Mansiisk Autonomous district is held and 8 submeridional structural-formational zones are determined with different sets and structure of composing formations, history of geological development and physical regions. On the basis of generalization and analysis data, we have compiled a new geological map of the pre-Jurassic base of the Eastern part of the Khanty-Mansiisk Autonomous district, significantly refining the predecessors' maps.