Reinterpretation of seismic materials of DSS and gravity modeling along the profiles 25, 28 and 29 in the Black Sea and the Sea of Azov
© Baranova E.P., Egorova T.P., Omelchenko V.D.
The paper represents the results of reinterpretation of DSS data along separate profiles carried out more than 30 years ago in the Black Sea region. Velocity modeling using the ray-tracing method was accomplished on two roughly N-S-trending lines - on the DSS profile 25 in the western part of the Black Sea and along the line made up from two DSS profiles - profile 28 in the Sea of Azo and profile 29 in the central part of the Black Sea. In addition, 2D gravity modelling was implemented. Velocity model on DSS profile 25 shows two major domains (from south to north): (1) thin (5 km) oceanic crust of high velocity and density, which underlines thick (12-13 km) strata of Cenozoic oceanic sediments in the West-Black Sea Basin and (2) thickened (?39 km) continental crust on the shelf within the Scythian Platform and southern slope of the Ukrainian Shield. In between these contrasting domains there is a transition block, which is distinguished by the presence of high-amplitude rift-associated fault along the shelf margin, which is assumed to be related with the origination of the West-Black Sea Basin. Velocity model on seismic profile 29 demostrates as well (but in reverse order) thin oceanic crust of the north-western limitation of the East-Black Sea Basin and block of continental crust of the Mid Black Sea Ridge, underlain by the Moho boundary at the depth of 29 km. The Mid Black Sea Ridge itself is represented by an echelon-like system of several (three) blocks, where basement elevates from the depth of 10-11 km on the Andrusov Ridge to 6 km on the Archangelsky Ridge. Seismic boundary at the crustal base (Moho interface), dippening from the East-Black Sea basin below the Andrusov Ridge, relates, most probably, with formation of the East-Black Sea Basin, the opening of which could be initiated by strike-slip movements along.