Tectonics of Eastern Anatolian Plateau; Final Stages of Collisional Orogeny in Anatolia
Yücel Yılmaz1, İbrahim Çemen2 Erdinç Yiğitbaş3
1- Istanbul Technical University, Mining Faculty, Maslak, 80620 Istanbul Turkey. yyilmaz@khas.edu.tr. Corresponding author.
2- The University of Alabama, Department of Geological Sciences, Tuscaloosa, Alabama, United States. icemen@ua.edu
3- Çanakkale 18 Mart University, Department of Geology. Çanakkale-Turkey.eyigitbas@comu.edu.tr
Abstract .
The East Anatolian High Plateau, part of the Alpine-Himalayan orogen, is a 200 km wide, approximately E-W trending belt surrounded by two peripheral mountains of the Anatolian Peninsula. The plateau is covered by a thick, interbedded Neogene volcanic and sedimentary rocks. Outcrops of the underlying rocks are rare. Therefore, contrasting views were proposed on the nature of the basement rocks.
New geological and geophysical data suggest the presence of an ophiolitic mélange-accretionary complex under cover rocks of Eastern Anatolia. The cover units began to be deposited during the closure of the NeoTethyan Ocean that was located between the Pontide arc to the north, and the continental slivers drifted away from the Arabian Plate to the south. The surrounding orogenic belts experienced different orogenic evolution. The Eastern Anatolian orogen was formed during the later stages of the development of the surrounding orogenic belts. In this period, the mélange-accretionary prism that occupied a large terrain behaved like a wide and thick cushion, which did not allow a head-on collision of the bordering continents.
NeoTethyan oceanic lithosphere was eliminated from entire eastern Turkey by the Late Eocene. The eastern Anatolia began to rise when the northern advance of the Arabian Plate continued after the total demise of the oceanic lithosphere. The present stage of the elevation of the East Anatolian Plateau as a coherent block started during the Late Miocene.