Geomorphological Properties and Tectonic Activity of Alaköy Fault (Lake Van Basin- Eastern Anatolia)

Abstract

The Lake Van Basin, formed in the Late Pliocene, is located on the north of Bitlis-Zagros Suture Belt and attained its final shape with Quaternary volcanic activity. Young structures created by N-S compressional neotectonic period are observed in lacustrine deposits of Lake Van. Nearly E-W trending Alaköy Thrust Fault is one of these structures which is 20 km far from Van city center. The most damaged areas due to the 23 October 2011 earthquakes (7.1 and 5.6 Mw) and the intense aftershocks are situated on this fault zone which can be followed along 25 km by geomorphologic indicators. The fault cuts off the Quaternary coastal lacustrine deposits and juxtaposes them with basement rocks of the basin in patches. The activity of the fault can be detected by unpaired terraces near the channel, interrupted drainages, fans formed on the fault and topographic slope breaks. In this study the fault plane measurements of Alaköy Fault are presented for the first time. The purpose of this study is to discuss the recent activity of Alaköy Fault within a regional content with the help of structural and geomorphologic data.