Tertiary Structural Evolution, Paleogeography and Sedimentation in the SW Black Sea Deep Offshore

This paper illustrates the structural control on the evolution of Late Mesozoic and Tertiary depositional system in the West Black Sea Basin focusing on Offshore Bulgaria. The presence of Oligocene turbidite systems Offshore Bulgaria is demonstrated by well calibration and seismic stratigraphic evaluation. The West Black Sea was a starved basin in a passive margin context from the Upper Cretaceous time. Taurus Block collision with the Eurasian Plate during the Paleocene induced uplift and thrusting of the Balkan orogenic belt (Balkanides/Rhodope/Strandzha) and creation of associated foreland on the Western margin of the Black Sea (Kamchia Basin) which captured sediments eroded from the crystalline Rhodope/Strandzha Massif during the Eocene. Subsequently, in the Late Eocene, the end of Balkanide orogenesis seemed to modify the paleodrainage system allowing these sediments to spread into the basin. Oligocene turbiditic sandstones found in Samotino Melrose-1, on the Bulgarian shelf, are interpreted as a canyon-fill in a partial shelf-bypass zone, potentially feeding turbiditic systems to the east. Furthermore the different levels of sandstone deposition identified on seismic can be correlated to variations of Oligocene sea level documented in the East Paratethys Basin.