Structure and development of the eastern part of northwestern shelf of the Black Sea (according to the results of geophysical data interpretation along II profile of CMRW)

Abstract

Complicated block structure of the eastern part of northwestern shelf of the Black Sea has been found as a result of two-dimensional gravity modeling and plotting paleostructural section (according to the MVS CMP data). Scythian plate consists of sub-continental crust from 31.5 km thick under the Marginal bench to 43.5 km thick on the border with East-European platform (EEP). Formation of the Marginal bench, limited from the both sides by deep faults of post-maikopian age is related to dipping of the West Black Sea lowland. In the core of the Calamitian swell presence of a body with density, specific to the rocks of tavrian series has been found. The structure of the swell has been formed as a result of dipping the margins of Triassic-Jurassic basin during the Cretaceous. Crystal basement of the Carkinite sag consists of alternation of blocks with normal and increased density values caused by implantation of the mantle material during riftogenesis. On the northern side of the sag a lens of Middle-Upper-Jurassic sedimentary-volcanogenic rocks has been revealed by modeling under Cretaceous sediments. According to the results of studies the border of the Scythian plate and EEP is found to be much northward from the Golitsyn’s structure. The velocities of sediments accumulation, determined on the basis of data on the thicknesses of sedimentary complexes along the profile allowed to specify the dynamics of tectonic movements, which showed that all the structures of the studied area had their own development history during Meso-Cenozoic.