Oil and Gas Occurrences in Southwest Turkey

Abstract

In SW Turkey, on both sides of the Antalya basin, two continental micro-plates can be distinguished: the Anatolian micro-plate to the NE and Bey Dağlari micro-plate to the W. These micro-plates are composed of a Paleozoic basement of Gondwana type, surrounded by Mesozoic carbonate platforms. From south to north the Bey Dağlari platforms are made of shallow marine carbonates from Triassic time up to Cenomanian. The southern part of this carbonate platform remained under shallow marine conditions up to the Eocene. On the contrary, the northern part subsided during Late Cretaceous time. In the Bey Dağlari platform, occurrences of organic materials are known in the Triassic and in the Early Cretaceous-Cenomanian carbonates. Rock-eval analysis indicate 0.25 to 1.46% total organic carbon (TOC). These facies could have represented a source rock for oil and gas. In the same area the uncomformable Early Miocene carbonates are made of bioclastic calcarenites. In some areas these calcarenites are dark colored and contain oil. These carbonates represent a reservoir rock The Anatolian micro- plate is also composed of shallow marine carbonates from Triassic time up to Eocene. Organic materials are known in the Akkuyu formation, Late Jurassic in age. According to organic geochemical characteristics, this unit is a good source rock. The total organic carbon (TOC) content of this unit is up to 12%. In the same area, other occurrences of oil and gas are known in two locations, Çirali to the SW of Antalya Bay and the Kizildag to the NE of Antalya. The Çirali location is known since the ancient civilizations as Chimera. Gas of this area is pouring out from a complex tectonic imbricate structure including ultrabasic rocks. The source rock and the reservoir are poorly known. The Kizildag is a large klippen of peridotites in the Antalya nappes complex. Liquid petroleum seepage is observed in this ophiolitic unit.