Depositional environment characteristics of Ulukışla Evaporites, Central Anatolia, Turkey.

This paper examines evaporated deposits of gypsum known as the Ulukışla Evaporites located in the Ulukışla Basin, central Anatolia, Turkey. The Late Eocene compression between the Eurasian and Afro-Arabian plates formed numerous shallow epicontinental basins in SE central Anatolia. During this period, the Ulukışla Basin was a shallow marine environment. The composition of the Ulukışla Basin indicates that gypsum and stromatolite were deposited due to an arid climate and sea level oscillation between 37.25 and 38.52 Ma. Oxygen, sulfur, and strontium isotopes and the geochemistry of the evaporated rocks were measured to understand the paleoenvironment of this formation. Trace element analyses of Fe, K, Mg, Na, Mn, Sr, Ni, and Cu from the gypsum samples showed very high variability. The average K/Na, Sr/Ca, and Mg/Na were measured to be 0.4, 2.35, and 2.9 %, respectively, which indicates that the Ulukışla gypsum lies in a formerly hypersaline environment. Sr/Sr, O, and S isotope ratios indicate that the gypsum was deposited in marine water then mixed with fresh continental water. [ABSTRACT FROM AUTHOR]