Integral assessment of the geodynamic conditions for the formation of the Black Sea basin and connection with the current regime of groundwater in its northwestern shelf

Abstract

The paper has a multidisciplinary character connecting bathymetric, geophysical and geological information to innovatively reconstruct the geodynamic conditions of the Black Sea basin formation, their influence on the modern relief and groundwater regime within its northwestern shelf as a reference region. The major goal is the rationale of modern geodynamic settings for the Black Sea Basin against the back- ground of the processes of its closure under tangential compression conditions, as well as their relation- ship with the hydrogeological conditions of the shelf zone. As primary evidence, the author determined the spatial positions of the Constanta-Sinop and SubPontian Suture Zones, pinpointing absorption locations of the Earth's crust at subduction zones. The facts and arguments presented in this paper are well integrated into the scheme of the oncoming of the Pontides island arc to the Eurasian Plate and the gradual closure of the back-arc marginal Black Sea Basin with a crust of transitional-type crust. The specific feature of the study is an innovative approach to comprehensive analysis of data that are a result of geological and geophysical works within the Black Sea water area. In doing so, major attention is paid to the spatial morphostructural analysis and interpretation of newly integrated digital data array, as a result of bathymetric surveys, namely the EMODnet 2019—2022. The subject of analysis is the basic structural surfaces, including the Modern and on its margin consolidated basement. New justification is formulated on the confinement of gas seeps and mud volcanoes, within the Black Sea Basin, to the deep earth`s crust structures. The graphical correlation of the mentioned ones is performed as well as their spatial position in the structural-geodynamic model of the region is theoretically substantiated. A generalized geomorphological zoning of the northwestern shelf of the Black Sea with the identification of the Dobrogea, Odesa and Kalamit zone is proposed. Within the Odesa geomorphological region, an integrated geological and geomorphological analysis was carried out and, as a result, dividing the shelf into submarine groundwater discharge (SGD) zone of aquifer was substantiated. The study, carried out by the author is of crucial importance to understanding the tectonic and geo- dynamic characteristics of the Black Sea Basin as well as for forecasting SGD zones and fresh groundwater resources. It is recommended to set targeted prospecting works to assess fresh groundwater resources in order to meet the water needs of coastal communities.