Сollision deformations of the Dnieper-Donets Depression. Article 1. Tectonics of the articulation zone with the Donets folding structure
Authors: Bartashchuk Оleksiy 
Published: May 2021

The article is the first part of a trilogy devoted to the study of post-rift deformations of the riftogenic structure of the Dnieper-Donets paleorift. The mechanisms of collision warping of the horizons of the sedimentary cover of the southeastern part of the Dnieper-Donets depression are considered. According to the previous mapping data, the tectonic deformations of the sedimentary cover were controlled by systems of faults of the north, north-west, and south-east vergence. The lattices of tectonites of the Hercynian, Lamaric, and Attic generations determine the specific “cross-thrust” structure of pushing. Overthrusts and linear folding of three generations permeate the sedimentary sequence of the transition zone from east to west for hundreds of kilometers within the eastern part of Izyumsky paleorift segment. The analytical base of the research was the materials of geological mapping of the zone of the junction of the depression with the Donets fold structure. Using field definitions of the tectonite vergency of the Hercynian, Laramide and Attic phases of tectogenesis, the original method of reconstruction of tectonic deformation fields and tectonophysics analysis of structures, collision deformations of the sedimentary cover of the south-eastern part of the Dnieper-Donets paleorift are studied. The tectonophysical analysis of tectonites of different ages indicates that together they control the cover-thrust and folded deformations of the riftogenic structure. Overthrusts and linear reverse-folding of three generations form the West-Donetsk integumentary-folding region, within which a segment of the same name tectonic thrust is distinguished. By pushing the system of repeatedly deformed, crushed into folds of geomass sedimentary rocks on weakly deployed syneclise deposits, the riftogenic structure of the south-eastern part of the basin is completely destroyed. The structural-tectonic framework of the allochthone, pushed from the side of the Donets structure, is composed of dynamically conjugated lattices of Hercynian, Laramide, and Attic tectonites. They control the echelon backstage of linear reverse-folds, tectonic plate-covers of transverse extrusion of sedimentary geomass from axial to airborne zones and folded covers of longitudinal thrust from the south-east. The riftogenic structure of the transition zone between the Dnieper-Donets basin and the Donets folded structure was completely destroyed by deformations of three generations of platform activation. The dynamically coupled tectonite lattice, the overlays, and the folded zones of the Hercynian, Laramide, and Attic generations jointly form the West-Donets fold-fold region within its boundaries. The main tectonic element of the area is the eponymous subregional tectonic thrust segment. The central structural zone is Veliko-Kamyshevakhskaya, Novotroitskaya, Druzhkovsko-Konstantinovskaya and Main anticlines. The central zone divides the body of the segment into two tectonic regions according to the tectonic style and intensity of deformation of the sedimentary sequence. The northern part is occupied by the Luhansk-Kamyshevakhsky region of the rocky-layered linear folding of the thrust, and the southern part is the Kalmius-Toretsky region of scaly tectonic covers.