Thrace Basin Thrace Basin The European side of Turkey is called the Thrace Basin. It is the largest and thickest Cenozoic sedimentary basin in Turkey. The basin is triangular shaped, trends WNW-ESE and was formed by extension in late Middle Eocene to latest Oligocene times. This gas prone basin is located northwest of Istanbul, Turkey. About 9,000 meters of Eocene-Miocene marine clastics and continental sediments were deposited. Several basement faults were reactivated and underwent strike-slip motion in late Miocene times where the famous North Anatolian Fault bounds the southern part of the basin. The Cenozoic sedimentary succession, overlying Paleozoic to Mesozoic metamorphic
Geography of Turkey of the sizable Greek-speaking community of western Turkey were forced to resettle in Greece, while the majority of the Turkish-speaking residents of Thrace who were not forced out during the Balkan wars were removed to Turkey. The boundary with Bulgaria was confirmed by the Treaty of Lausanne (1923). Since 1991 the more than boundary with the former Soviet Union, which was defined in the 1921 Treaty of Moscow (1921) and Treaty of Kars, has formed Turkey's borders with the independent countries of Armenia, Azerbaijan, and Georgia. The boundary with Iran was confirmed by the Treaty of Kasr-ı Şirin in 1639.