"Young platform"- traditional intelligence and reality (geodynamic aspect)

Purpose. Transition of theoretical tectonics to the mobilistic position has changed a notion of the nature of geological processes, and hence approaches to re-comprehesion on the new high-quality level of views of the tectonic nature of the areas which are traditionally interpreted as “young platforms”, and notions of which were based on the classical studies of geosynclines. Methodology. Mobilistic theory of tectogenesis is the important component of the geodynamics basis of the analysis. Methodology of investigations include: formational analysis of Proterozoic and Phanerozoic series, structural analysis, and paleogeographic and paleogeodynamic reconstruction. For interregional correlation the methods of comparative analysis (stratigraphic, formational, tectonic) were used. Findings. Formation of the “young platforms” as an especial tectonic element of the lithosphere traditionally was distinguished by geosynclinal pre-history. It was accepted that their structural plan was developed under the influence of differential vertical tectonic movements that were derivatives from the processes of geosynclinal folding. Such a postulate has gained an axiomatic form and has submitted to itself the direction of the thoughts of many investigator for almost a half-century. On the schemes of tectonic regioning (zoning) of the Ukraine’s territory, two young platforms are traditionally distinguished, namely: Scythian one in the south and the West-European in the west.  But existing notion of their structure and evolution were based on the principles that already are contrary to new geological-geophysical material and are out of accordance with the level of the modern theoretical tectonics. iIn the recent interpretation, the Scythian platform is interpreted as “Scythian terrain” which was a constituent part of Epi-Grenville Supercontinent of Rodinia at an interval of 1100 to 950 mln years. After its disintegration (850–630 mln y.) the Scythian terrain joined up with the East European Craton. In the Late Proterozoic – Early Paleozoic in the zone of collision the deformation belt is formed that is now documented as a green shale complex and a system of overthrusts in the Lower Paleozoic series. On the tectonic map of the West Ukraine one can distinguish a zone which is thinning out between the East European Platform and Carpathian construction in the form of triangle. It is considered as a fragment of the young West European Platform which occupies the territory of Variscides of West and East Europe. Executed investigations have shown that within the limits of this area of Variscidesthat no tectonic structures have been formed neither during the Caledonian or  Baikalian epochs. This plot of the Earth’s crust consolidates allochtonous structures of different age, structure, and genesis. This microplate structural ensemble of mosaic style of structure have a collisional origin as a result of the different –directed interaction of the Gondwana, Lavrasia, and Baltic continents. The analysis of the existing material, taking into consideration new geological-geophysical information, testifies to that within the limits of Western and Central Europe is absent such a set of indications which give grounds to interpret that plot of the Earth’s crust as the “young platform”, and correspondingly there are no reasons to maintain the “young West European Platform” within the limits of Variscides on the whole. Originality. Notions of tectonic nature of the “young platforms” have been re-comprehended. Investigations have shown-that such a set of indications serve as the basis for distinguishing plots of the Earth’s crust as “young platforms” have turned out to be erroneous from the position of modern theoretical tectonics. Practical Value. Overthrust conception of the formation of structures in sedimentary series in such regions determine unconventional and perspective direction of search for hydrocarbons in overthrust and underthrust structures, that is to say – structures new by their tectonic position.