Abstract: During the Early Tertiary, the southern part of the Tuzgölü Basin, Ulukışla area and its immediatesurroundings was an ocean from which an ophiolitic complex was emplaced southwards on the Bolkardağ region inLate Crateceous times. From the Tertiary to the present, three different groups of rock assemblages seperated fromeach - other by regional unconformities have developed in this basin in relation to Oceanic, and post oceanic periodsrespectively.These groups are named as Ulukışla, Kılan and Bohçadikmen groups accordingly and, taking litological differences in consideration, they are divided in members and formations.The Ulukışla group, which is the flysch of this oceanic basin comprises islands-arc volcanics and relatedcarbonates and elastics, and various turbiditic sediment deposited in its deeper parts.The Kılan group which represents the molasse of the basin is composed of evaporites, fresh-water carbonatesand terrestrial elastics.Finelly, the Bohçadikmen group, which is the post - oceanic cycle of this through, comprises several forms ofcontinental and lacustrine deposits.At the beginning of the Tertiary, the region was in the form of a closing ocean inwhich an island - arc complex was developing. Progressive closure occured from the north to the south in consequence of collisions of a consecutfve continent with an island - arc and its subsequent collision with a continent.