SUBSURFACE STRUCTURAL GEOLOGY AND TECTONO-STRATIGRAPHY OF THE OFF-SHORE AKCAKOCA-AMASRA AREA, WESTERN BLACK SEA BASIN, TURKEY

The Black Sea Basin contains two sub-basins with different tectonic origin; the Western and Eastern Black Sea basins. The Western Black Sea Basin formed as a result of rifting of the Moesian Platform in Early Cretaceous. The Eastern Black Sea Basin formed during the counterclockwise rotation of Eastern Black Sea margin block around a rotation pole located north of Crimea. This rotation was coeval with the opening of the Western Black Sea Basin, but continued until the Miocene.

During this study we have interpreted nine seismic reflection profiles to determine the subsurface structural geometry and tectono-stratigraphic evolution of the off-shore Akcakoca-Amasra area within the Western Black Sea Basin. A velocity model is constructed based on sonic data from the Akcakoca-1 well which is located along one of the seismic profiles. The velocity model is used for depth conversion of the seismic profiles to construct structural cross-sections.

Our preliminary interpretations suggest that a major unconformity separates the syn-rift and post-rift stages. The two stages have their distinct sedimentological and structural features. This basin contains turbiditic fans and onlap surfaces in the post-rift stage. The post-rift stage is marked by anticlinal structures in the sedimentary package caused by the possible inversion tectonics. This compression was followed by extension which locally shaped the basin between Akçakoca and Amasra as a Neogene Basin.