Kinematics of the East Anatolian Fault Zone between Turkoglu (Kahramanmaras) and Celikhan (Adiyaman), eastern Turkey

Abstract

In this study we determined the stress regime acting along the East Anatolian Fault Zone between Turkoglu (Kahramanmaras) and Celikhan (Adiyaman), from the Neocene to present-day, based on the inversion of striations measured on faults and on the focal mechanisms of earthquakes having magnitudes greater than 5.0. The inversions yield a strike-slip stress regime with a reverse component (i.e., transpression) operative in the Neocene to present with a consistent N-to NW-trending or, axis 156 +/- 11 degrees and an E- to NE-trending sigma(3) axis, sigma(7) 9 degrees sigma(3), producing left-lateral motion along the East Anatolian Fault Zone. The inversions of focal mechanisms yield a strike-slip stress deviator characterized by an approximately N-S (N1 degrees W)-trending sigma(1), and an approximately E-W (N89 degrees E)-trending sigma(3) axis. Both the kinematic analysis and structural observations indicate that the stress regime operating in the study area has had a transpressional character, giving rise to the Mio-Pliocene compressive structures (reverse faults, thrusts and folds) observed in the study area. Field observations allow estimation of a Pliocene age for the strike-slip East Anatolian Fault Zone.