INTERPRETATION OF THE THRACE BASIN IN THE NORTHWESTERN TURKEY, USING SEISMIC REFLECTION, WELL LOG, AND GRAVITY DATA

Turkey's geological environment is structurally complex with strike-slip and compressional tectonic regimes, and it does not have extensive oil and gas basins because of the most of the basins are young and in within active tectonic environments. However, the Thrace basin which is located in northwest Turkey and is positioned between compressional mountains and active trenches and surrounded the granitic and mica-schist rocks of the Istranca (Strandaja) and Rhodope Massifs is unique in Turkey as it contains a high volume of reservoir and source rocks. Plate motions involving the African, Anatolian, and Eurasian plates occurred during Maastrichtian and Miocene times that helped formed the Thrace basin. Oil production is mainly from Oligocene-aged shales and Eocene-aged siliciclastic rocks. Also, these siliciclastic rocks have the potential for gas production. In this study, seismic reflection, well log, and gravity data were used to investigate potential hydrocarbon reservoirs and interpret the structural features within the Thrace basin. This analysis include constructing a three-dimensional seismic model of the formations, petro-physical features of the rocks from well logs, and gravity anomaly maps including Bouguer, Regional, and total horizontal derivatives. The gravity anomaly maps indicate that the basin is composed of two depositional centers separated by a structural uplift that trends north-south.