Kinematics of the faults around the Koyulhisar (Sivas) region on the North Anatolian Fault Zone

Abstract

The study area is located on the eastern part of the North Anatolian Fault Zone (NAFZ) around the Koyulhisar (Sivas) region. The region is represented by a 6-8 km wide and 32 km long deformation belt. This belt is divided into 5 fault segments by Toprak (1988) as North Anatolian Master Fault, Koyulhisar Fault Set, Kelkit Fault Set, Sihlar Fault Set and Kurucay Fault Set. In this study, a detailed fault kinematic analysis were carried out along the Sihkar, Camliyaka, Saytepe and Dumanlica Fault Sets around Koyulhisar and its surroundings. The result of kinematc analysis indicates that the region is under the effect of NW-SE compression and NE-SW extension. Morphotectonic structures and microseismic activity reveals the right lateral strike slip activity of the North Anatolian Fault Zone in this region. Intense landslide activity in the region is seen. One of the severe landslides occurred in Koyulhisar in 2000 is still affecting the region. GPS monitoring of this landslide reveals an average of 2.5-7.4 mm/year slip rate.