Morphometric and morphotectonic analysis of thesegment of the ecemiş fault zone between pozanti (Adana)and tarsus (Mersin)

The PhD study focuses on the morphotectonic activity and morphometric analysis of the segment between Pozantı (Adana) and Tarsus (Mersin), located at the southern end of the left-lateral strike-slip Ecemiş Fault Zone. The study area is surrounded by significant morphological uplifts, such as the Aladağlar to the north and east, and the Bolkar Mountains to the north-northwest. In this research, which was carried out to determine the morphotectonic features and tectonic activity of the Ecemiş Fault Zone, whose lineament can be clearly observed in land and satellite images between Pozantı and Kayseri, but cannot be clearly determined in the southern parts of Pozantı, studies were carried out on the morphological, morphometric and tectonic properties of the study area. Ecemiş Fault Zone borders the eastern part of the Central Taurus Mountains and the western part of the Eastern Taurus Mountains in the study area and represents a very complex area in terms of tectonic aspects. This region contains five tectonic slices derived from different sources and basins. Since the stratigraphic features of the formations in these slices have been previously investigated in detail by many researchers in the region, the existing formation names have been used as they are. The units belonging to the Taurus Belt cropping out in the region are as follows, from bottom to top: Bolkar Mountain Unit, Namrun Tectonic Slice, Aladağ Unit, Bozkır Unit and Quaternary units. In this study, the morphological characteristics of the study area were evaluated and morphometric analyzes were performed. Eight watershed located around Gülek (1), Akçatekir (2), Kuşçular (3), Karakılıç (4), Çamlıyayla (5), Gömmece (6), Dorak (7) and Damlama (8) have been identified for morphometric analyses. Additionally, eight micro-watershed developed between Pozantı and Akçatekir have been identified based on the linearity of the Akça-Kızılık and Hamidiye-Fındıklı fault segments within the Ecemiş Fault Zone in the region. Morphometric analyses have been conducted on the identified drainage watershed to determine the neotectonic activity of the study area. In this context, morphometric indices called hypsometric integral of drainage basins, stream length slope index and the ratio of valley floor to valley height were used. Although the hypsometric integral data indicate the morphological stage of stability-maturity in the study area, they also suggest the presence of tectonic activity in the region. The SL index data also confirm the tectonic activity of the region. In the region, the block located in the western part of the left-lateral strike-slip Ecemiş Fault Zone has moved downward in relief to the south-southwest, with strike-oblique (normal) movements, compared to the block in the east. As a result, the Paleocene-Eocene units on the rising eastern block have not been exposed due to erosion, while these units have been preserved in the western block, particularly around the Namrun-Atdağı area. In order to evaluate the tectonic features of the region, measurements were taken on the planes of the faults that are exposed in the field, and rose and contour diagrams were created; From the measurements taken from the Late Permian aged Karluğuntepe and Yellice formations, it is seen that the compressional forces; N85W/S85E, from measurements taken from the Jurassic-Cretaceous aged Demirkazık Formation; N55E/S55W, N5E/S5W, N55W/S55E, from measurements taken from the Upper Senonian aged Kızıldağ Melange; N15W/S15E and N55W/S55E, from measurements taken from the Upper Paleocene-Middle Eocene aged Güzeller Formation; N45W/S45E, from measurements taken from Oligocene-Lower Miocene aged Çukurbağ and Burç formations; N45W/S45E, from measurements taken from Oligocene-Middle Miocene aged Gildirli, Kaplankaya and Karaisalı formations; N40E/S40W, from measurements taken from Plio-Quaternary aged units; It was observed that it was concentrated in the N62E/S62W directions. Earthquakes with a magnitude of 4.5 (Mw) or greater during the instrumental period have been detected within circular areas with a 100 km radius centered around Pozantı (Adana) and Kayseri, and a probabilistic seismic hazard analysis has been performed for these regions. With this analysis, the probabilities of earthquakes with magnitudes between 4.5 ≤ Mw ≤ 7.5 occurring within 10, 50, 75, and 100 years, as well as their approximate recurrence periods, have been established. Additionally, the seismicity of the study area has been examined by analyzing earthquake data from the historical and instrumental periods, as well as records of seismic activity along the fault zone, revealing that the area has remained seismically quiet for a long time.