New insights on the crustal structure of the eastern black sea basin from long-offset seismic reflection data

Estimating the degree of lithospheric stretching, and identifying the distribution of crustal types, are important elements in oil and gas exploration activity, because this information is used for thermal modelling of hydrocarbon maturation. The Eastern Black Sea Basin (EBSB) is a frontier basin for hydrocarbon exploration, but the deep-water setting (∼2200 m) and the presence of a thick sedimentary sequence (∼10 km) limit conventional seismic imaging. The EBSB is considered to be partially underlain by oceanic crust, but the distribution of crustal types and the structures accommodating the stretching are still poorly known. We use long-offset reflection seismic data, acquired in 2011 by Geology Without Limits and ION GXT, to image key elements of rift-basin settings such as thinned continental crust, tilted fault-blocks, syn- and post-kinematic sequences, the top of the acoustic basement and Moho. We differentiate the basement by examining seismic reflectivity patterns as an indicator of crustal type. We interpret variations in basement morphology to indicate the presence of a continent-ocean transition of enigmatic nature. This information will be used to further investigate the nature and thickness of the crust and to provide insights into mechanisms of continental extension and rifting in back-arc settings.