November 15-17, 2019, Ankara, Turkey, Proceedings, 689-725 689 A REVIEW OF PALEOZOIC - MIOCENE PETROLEUM SOURCE ROCKS OF TURKEY BY PALEOGEOGRAPHIC AND PALEOTECTONIC DATA: NEW INTERPRETATIONS AND MAJOR OUTCOMES Adil OZDEMIR 1 and Yildiray PALABIYIK 2 1 Adil Ozdemir Consulting, Ankara, Turkey adilozdemir2000@yahoo.com 2 Istanbul Technical University, Department of Petroleum and Natural Gas Engineering, Istanbul, Turkey palabiyiky@itu.edu.tr Abstract Alpine Mobile Belt (Tethyan Region) is a huge oil and gas belt in which Turkey is located. Type-II kerogen-containing high-yield source rocks formed prosperous oil and gas reserves in the Tethyan Region, a marine route between the Gondwana and the northern continental groups (Boreal) during the Silurian-Holocene period. The source rock deposition in the region was continuously being supported by the successive opening and closing of Paleotethys and Neotethys. Turkey contains foreland and intermontane basins, and thrust-fold belts (traps) which are originally connected with the Tethyan tectonics. According to the paleogeographic and the paleotectonic data in this study, there are widespread carbonate rocks (source and reservoir rocks) and evaporites (seals) as well as clastic rocks (source rocks) in Turkey. The presented paleogeographic and paleotectonic data and their interpretations show that Turkey has prosperous petroleum source rocks that were formed in the Paleozoic-Miocene interval. Ordovician-Silurian, Devonian-Carboniferous, Permian-Triassic, Jurassic-Cretaceous, Paleocene, and Oligocene-Miocene are the important geological periods in terms of source rock occurrence. Keywords: source rock, paleogeography, paleotectonics, oil and gas potential of Turkey, geological evolution of Turkey, oil and gas exploration 1. INTRODUCTION Alpine Mobile Belt (Tethyan Region) is a profound oil and gas belt where Turkey is located (Fig. 1). Tethyan region covers from the coast of the Gulf of Mexico and South America to Southeastern China and the South China Sea. The Sirte Basin in North Africa, the Gulf Coast of North America, the Gulf of Mexico, the Maracaibo Basin of Venezuela, the Magdalena Basin of Eastern Venezuela, and the coastal of Iranian-Zagros basin in the Middle East are the major petroleum basins which are associated with Cretaceous source rocks in this region (Ruofei et al., 2014). Type-II kerogen-containing high-yield source rocks formed productive oil and gas reserves in the Tethyan Region, a marine route between the Gondwana and the northern continental groups (Boreal) during the Silurian-Holocene period. The source rock deposition in the region was continuously being supported by the successive opening and closing of Paleotethys and Neotethys. The region contains foreland and intermontane basins, and thrust-fold belts which are originally connected with Tethyan tectonics. There are widespread carbonate rocks and evaporites as well as clastic rocks in the region. Besides, it has provided the development of rift/graben structures suitable for the formation of sill- containing basins. Tethyan basins cover less than one-fifth of the lands and continental shelves of the world, while they include more than two-thirds of the oil reserves of the world (Klemme and Ulmishek, 1991). More than 90% of the known oil and gas reserves in the world has been generated by source rocks formed in 6 geological times (Fig. 2) (Klemme and Ulmishek, 1991) as follows: