Examination of stress state between Doğanyol (Malatya) and Çelikhan (Adıyaman) on the east Anatolian fault zone

The East Anatolian Fault Zone (EAFZ), which was developed in the continent due to the convergence between the Arabian Plate and the Anatolian Block, has a significant impact on the tectonic evolution of the Eastern Mediterranean. In this study, the part of EAFZ between Doğanyol (Malatya) and Çelikhan (Adıyaman) was examined. Faults in the study area were mapped with field studies and remote sensing methods. During field studies, the fault geometry and the morphotectonic structures, which was exhibited along the fault, were examined, and also slip data along the deformation zone were measured from the fault planes for paleostress analysis. Stress directions of the kinematic data evaluated by numerical analysis program are calculated by rotational optimization method deformation type was determined. According to results obtained from the field observations and paleostress analysis, there are three different deformation phases in the study area. First deformation phase; it corresponds to NW-SE compressional strain during the Late Eocene-Late Oligocene time interval. The second deformation phase is based on the subduction and the continent-continent collision of Middle Miocene-Pliocene time interval; shows the approximate N-S compressional strain. The last deformation phase, depending on the change in stress as a result of the convergence from the Late Pliocene to the present day, reflects the left lateral strike-slip regime developed under NE-SW direction compression. Strike slip tectonic due to NE-SW trending compression (last regime), which is the youngest phase in the study area, has also supported by morphological data indicating active tectonics (such as elongated ridges, stream shifts and linear valleys). In the rose diagram obtained as a result of the lineaments analysis carried out by remote sensing studies, the lineaments concentrated in the direction of N65°E reflect the left lateral EAFZ. As a result of the convergence between the Arabian Plate and the Anatolian Block, the study area has undergone three different deformation phases from the Late Eocene to present; the segments of the EAFZ developed during the last phase of these deformation phases (from the Late Pliocene to the present).