Thrace Basin basement, comprises interbedded fine to coarse grained clastics from a variety of depositional environments, turbidite, muddy carbonates with local reef developments, river channels and tuffs. More than 400 wells were drilled till 2008; 14 gas and 3 oil fields were discovered and all of them are producing. Main gas productions zones are between Eocene- Oligocene deposits; Hamitabat (turbiditic sandstones), Ceylan (tuffs), Sogucak (reefal limestone), and Osmancik (deltaic sandstone) formations. Shales of Hamitabat and Mezardere formations have good source potentials. Thrace Basin The European side of Turkey is called the Thrace Basin. It is the largest and thickest Cenozoic sedimentary basin
Eastern Macedonia and Thrace and weight of the five now abolished prefectures, Drama, Evros, Kavala, Rhodope and Xanthi. In this special case, the region of Eastern Macedonia and Thrace also succeeds the intermediate structure of the two super-prefectures of Drama-Kavala-Xanthi and of Rhodope-Evros into which the five prefectures had been grouped since 1994. Capital of the region is Komotini, which by population is the fourth largest city, following Alexandroupoli, Kavala and Xanthi. The region is divided into the Macedonian regional units of Drama, Kavala and Thasos and the Thracian regional units of Xanthi, Rhodope and Evros, which coincide with the territory of the former