Tectonic zonality of sedimentation cover in the Black Sea–Caspian Region

Abstract

The article focuses on modeling tectonic zonality of the sedimentation cover in the Black Sea–Caspian Region, and addresses the identification and validation of the Late Paleozoic, Mesozoic, Alpine and recent-time geodynamically active structures. The modeling shows that the significant events, which governed the evolution features of the geodynamically active structures, correlate with the recent time. That is the time when such sedimentation basins as Terek– Caspian, Indol–Kuban, Eastern Kuban and Karkinit have finally set. The first three basins in this list occur in the zones of the reverse geodynamic regime, with dominant extension and downwarping within the limits of cratons, and belong to the Black Sea–Caspian geodynamically active structure. The Karkinit basis belongs to the Scythian geodynamically active structure with generally compressive tectonics, dominant upheaval or relative stabilization. The tectonic features have had the critical influence on both formation of the sedimentation cover of the basins and spatial distribution of minerals. The article analyzes the development and evolution of the structural and geodynamic systems of the sedimentary complex in the Caspian region, and the results of structural and tectonic modeling of individual tectonic zones in the region. Based on the modeling results, an impor-tant feature of the morphology and structure of the basement surface and sedimentary complex in the Caspian Sea is the tracked sea extension of many elements detected on land. The main features of the morphology and structure of the basement surface and sedimentary complex in the Caspian region are the presence of superdeep depressions of the earth’s crust, with the basement depth up to 16 km or more in the North Caspian and up to 20–24 km in the South Caspian, as well as the distinct longitudinal (sublatitudinal) tectonic zonality of the region. Constructed as a result of the implemented reconstructions, the gener alized geological and tectonic model of the uneven-aged basement surface comprises the sea and continental parts of the region under study.