Sorgun-Yildizeli basin is an east-west trending asymmetric marginal foreland (peripheral foreland basin) formed as a result of the consumption of oceanic crust of the northern branch of Neotethys due to the collision of Sakarya continent in the north and Kirsehir Block in the south. It provides much information about the geodynamic evolution of the region. The basement of the study area consists of Late Palaeozoic-Mesozoic Akdagmadeni Massif. Akdagmadeni Massif was intruded by Cenomanian-Maastrichtian granitoids and is overlain tectonically by Late Cretaceous Artovaophiolitic melange within the Izmir-Ankara-Erzincan suture zone and by Cenomanian-Maastrichtian Darmik Formation. The volcano-sedimentary sequence deposited in Sorgun-Yildizeli foreland basin developed on the relicts of the Izmir-Ankara-Erzincan Suture Zone along the northern margin of Kirsehir Block and was named the Bogazköy Formation. The pelitic, clastic and coarse clastic levels of Upper Palaeocene-Middle Eocene Bogazköy Formation including Izmir-Ankara-Erzincan Suture Zone slices and olistostromes are differentiated as the Dolak member. Toward the inner part of the basin, a turbiditic sequence of conglomerate, sandstone, claystone including rare limestone beds was deposited, consisting of conglomerate, sandstone, claystone, rarely limestone and alternations of three different volcanic rocks (acidic, basic and intermediate) related to subduction and/or collision. Calc-alkaline lava and pyroclastics of basaltic and basalt-andesite composition were differentiated as the Pazarcik volcanic member, with lava and pyroclastics of dacitic and rhyolitic composition called the Sarayözü volcanic member and calc-alkaline lava and pyroclastics of andesitic, trachyandesitic and dacitic composition called Kiremitlik volcanic member in Sorgun-Yildizeli basin. According to the 40Ar/39Ar geochronologic method, the ages of 57.2±2.0 Ma and 56.7±1.8 Ma were obtained for Pazarcik volcanics, 48.8±1.5 Ma for Sarayözü volcanics and 45.1±1.3 Ma and 47.3±0.6 Ma for Kiremitlik volcanics. The reefal limestones which are not thick and occur in higher parts of the Bogazköy Formation were called the Limestone member. The uppermost section of the sequence which consists of generally clastic and coarse clastics is named the Konaci member. When the sedimentation and volcanism continued in the basin, gabbroic intrusions occurred as sills and laccoliths cutting the Bogazköy Formation. These gabbroic rocks were named the Yaycilar Gabbro. The age of 51.0 ± 0.7 Ma was found for the Yaycilar Gabbro with the 40Ar/39Ar geochronologic method. As a result of slab breakoff, the relicts of the consumed oceanic crust and the released massif were uplifted rapidly and the units of Middle-Late Eocene Tokus Formation were deposited transgressively on the Bogazköy Formation and on outcropping basement rocks in the basin which was controlled by an extensional tectonic regime. Upper Miocene-Pliocene (Incesu Formation), Pliocene and Quaternary terrestrial sediments were deposited unconformably on all older units.