Development of Evaporites and the Counterclockwise Rotation of Anatolia, Turkey

Abstract

In western and central Anatolia, numerous basins developed during Tertiary time. The major basins generally are not connected to one another, and cover large areas containing substantial sedimentary deposits. These basins include the following: Thrace, Gediz, Büyük Menderes, Beypazari, Tuz Gölü, Ulukisla, Sivas, Erzincan, Mus, and Adana, as well as others. Two significant differences can clearly be seen in the basin sequences: (1) the age of evaporites—in central Anatolia, evaporites developed during the Oligocene, whereas in western Anatolia they formed during the late Miocene; and (2) the character of the deposition—in central Anatolia, Oligocene redbed molasse deposits are abundant, whereas in western Anatolia they developed in the late Miocene and the beds are thin and not very abundant. Climate is one of the governing factors of deposition, controlled by elevation and latitude. Therefore, the difference in sequences between central and western Anatolia depends on these two parameters. In this study, paleogeographic latitudes of central and western Anatolia during the Oligocene and post-Oligocene are investigated in light of paleomagnetic data and GPS measurements. These studies reveal that the Anatolian block was subjected to considerable displacement along different latitudes by counterclockwise rotation. The change in climate by rotational displacement of central and western Anatolia over time is the main reason for differences in depositional characteristics and ages of the evaporites.