The structural and morphotectonic features of the Karakoçan fault zone

In this study, one of the most important neotectonic structures developed around the Karlıova Triple Junction where the North and East Anatolian Fault Systems intersects with the each other in the east which are the most prominent tectonic structures of Turkey, has been subject. Karakoçan Fault Zone, one of the sub zones of the Tunceli Fault System, extends in the direction of WNW-ESE between the Malatya Ovacık Fault Zone and the East Anatolian Fault System in the northwest and southeast, respectively. In the study, satellites images, digital elevation model (DEM) and remote sensing was used to reveal the structural and morphotectonic structure of the fault zone. It is observed that Karakoçan Fault Zone as a structural element has a zone approximately 110 km in length and 5-15 km in wide. The fault zone, starts from 3 km east of Altınoluk village in the southeast and traced to Tunceli province in northwest. Along the fault zone, several morphotectonic elements with regard to the strike-slip faults have been recognised. During the field mapping studies, it has observed that numerous structural fault segments ranging from 0.5 km to 32 km in length, extending parallel - semi parallel to each other and frequent spaced (100 m), represent it. Based on the satellite images indicated that the right lateral strike-slip fault zone has cumulative displacement values ranging from 70 m to 8.5 km. Five different deformation phases have been recognized in the study area from the Late Paleocene to the present time from fault slip data sets collected different rock units. The oldest deformation phase took place during the Late Paleocene to Early Eocene interval and is characterized by NE–SW extensional deformation. The second deformation phase took place during the Oligosen to Early Miyosen interval and is characterized by NW–SE compressional regime. The third deformation phase took place during the Latest Oligocene to Middle Miocene interval and characterized by NW–SE directed extension. The fourth deformation phase took place during the Late-Middle Miocene to Pliocene interval and characterized by N–S directed compressional regime. Finally deformation phase took place during the Pliocene to present-day interval and characterized by NE–SW directed compressional regime. It also observed from morphometric analyzes applied to the drainage basins, defined in the study area that the tectonic activity plays an active role in shaping of morphology of the region. Based on earthquake activity along the fault zone, it is suggested that seismic activity of the fault zone continue and have a potential to produce medium-sized earthquakes in the future.