The study area is situated in the southwestern part of the Sivas Basin. Sediments of the Ortakoy Formation (Middle-Upper Eocene) of flysch facies were deposited in a shallow marine environment and consist of interstratified sandstone, shale and calcareous mudstone. The Karaziyaret basaltic dikes cut the Ortakoy Formation. The Ortakoy Formation is comformably overlain by the evaporite-dominated Tuzhisar Formation. Gradual transitions between these two stratigraphic units crop out between Yenikoy and Yenituzhisar villages.