Коллизионные деформации Днепровско-Донецкой впадины. Часть 2. Геодинамические режимы и кинематический механизм деформаций

Abstract

The tectonic inversion of the Dnieper-Donets Basin and the Donets Foldbelt began in the Late Hercynian epoch under the influence of collisional movements of the left-sided knematics of the compression orogen on the edge of the Paleotethis. It is shown that as a result of gently inclined disruptions in the Paleozoic platform cover of the West Donets Graben, a thrust lattice was formed, which controlled the processes of collisional buckling of the horizons in the thrust and strike-slip modes. As a result of the displacement of geomasses from the axial zones of maximum compression to the zones of "geodynamic shadow" - in the direction of the Basin borders in the northern and axial parts of the Graben, linear uplift folds were formed, and in the southern - thrust covers. At the Late Mesozoic and Cenozoic, in the mode of interference of the uplift-thrust and strike-slip fields of the reverse, right-sided kinematics of movements, deformations of the Hercynian thrust lattice and the dynamically conjugated linear near-fault folding took place with the formation of coulisse articulated upthrust-fold zones and en-echelonly overthrust covers. The geodynamic setting of the grouping of the compression axes in the western part of the Donbass, which was experiencing orogenic uplift, caused the thrust of allochthonous geomasses to the syneclise related autochthon of the southeastern segment of the depression. In the West Donets Graben, this caused an increase in the section beyond the Hercynian Neoautochthon and the Cimmerian-Alpine allochthon with the formation of a clinoform wedging Segment. Along the main strike-slip faults, which form the tectonic rails of its invasion, geodynamic zones of geomass squeezing out, formed by curvilinear, en-echelonly upthrow folds, were formed. In the foreland of the Segment, at the ends of dynamically coupled thrust and strike-slip faults, a forward compression fan is formed; in the hinterland, on the roots of thrust covers, folded suture zones are formed. Based on the results of the kinematic analysis of the Hercynian and Alpine deformation structures, a new kinematic model of the tectonic inversion of the riftogenic structure of the Southeastern Segment of the Dnieper-Donets Basin has been developed. In accordance with it, the deformations of the sedimentary cover of the West Donets Graben were carried out according to the kinematic mechanism of a transverse orocline of pushing geomasses of the sub-thrust type, under the pressure of the tectonic stamp of the Donets Foldbelt.