Kinematics of the area between Palu-Uslu (Elazig) on the east Anatolian fault system in Turkey

The Eastern Anatolian Fault System (EAFS) is an intra-continental strike-slip fault system associated with the collision of the Arabian and African plates with the Anatolian plate in the Alp-Himalaya system. In this study, an area of about 80 km long, starting from Palu in the northeast and extending to Uslu in the southwest, was studied on the EAFS. The geometries of the faults in the study area are mapped with the help of remote sensing methods as well as field studies. Lineaments in the region were extracted by using automatic methods from Landsat (4-5) TM satellite image and a total 101 geological lineaments were defined and mapped in the study area. According to the Rose Diagram for the interpretation of the lineaments, the main orientations were determined as N7500E. The kinematic analysis of the fault slip data measured from fault planes by using Angelier (1990) method and the existence of at least three different deformation phases were determined in the study area. The oldest deformation phase in the study area occurred in the Late Oligocene-Middle Miocene (25-11 Ma). At this stage, the lithosphere of the Neo-Tethys ocean broke off and resulting the NW-SE direction of expansion on the plate above it. The second deformation phase is characterized by compression in the NW-SE direction in the stressed region. This deformation is thought to be related to post-collision compression which is effective in the region during the Late Miocene-Pliocene time. The youngest deformation phase in the study area is characterized by the presently effective NE-SW directional compression. This period, which has been effective since Late Pliocene, is associated with the activation of EAFS and many strike-slip faults. The data obtained as a result of field and remote sensing studies provide important and supportive information about the active stress axes in the region.