Structural and Sedimentological Properties of Lacustrine Deposits in Pliocene Dorutay Basin (özalp-Van)

Abstract

The collision between the Arabian and Eurasian plates caused to the formation of intramontane basins around Lake Van during and after Miocene. Pliocene Dorutay Basin (Özalp-Van) is one of these basins. Plio-Quaternary lacustrine deposits in the basin, uncomformably overlie the basement rocks composing of Carboniferous aged metamorphic rocks and Cretaceous ophiolites, indicate the existance of a widespread lake in the region at that time. This paleolake was around 2060 meter above the sea level and occupied in 150 km2 area. The boundaries of the paleolake can be determined using shore facies of lacustrine deposits. Sedimentary facies were investigated for understanding the depositional subenvironments and depositional processes of basin fill. Eight sedimentary facies and two facies associations representing to shallow lacustrine and shore subenvironment were recognized. Dorutay Basin is located on a seismically active region. Faults on boundaries of the basin and the basin fill play an important role on geological evolution of the basin. Especially the activity of Çırakköy Fault named with this study is the main reason of the changing from closed basin condition to open basin. Earthquake records and geomorphological data are showing the recent tectonnic activity of the basin. © 2015 Pushpa Publishing House. All Rights Reserved.