Tectonic geomorphology of the Kemalpaşa Basin and surrounding horsts, southwestern part of the Gediz Graben, Western Anatolia

Abstract

The Kemalpaşa Basin is one of the Quaternary basins in Western Anatolia and represents the south-western branch of the Gediz Graben system in this extensional province. This basin has been formed under the NNE-SSW trending extensional tectonic regime. It is bounded by a major fault, the Kemalpaşa Fault, in the south and it is bounded by a number of downstepping faults, called as Spildağı Fault Zone, in the north. Both margin-bounding faults of the Kemalpaşa Basin are oblique-slip normal faults. In order to better understand the activities of these faults, we investigated the tectonic geomorphology of the Kemalpaşa Basin and interpreted the effect of tectonic activity on the geomorphological evolution using geomorphic markers such as drainage basin patterns, facet geometries and morphometric indices such as hypsometric curves and integral (HI), basin shape index (B s ), valley floor width-to-height ratio (V f ) and mountain front sinuosity (S mf ). The morphometric analysis of 30 drainage basins in total and mountain fronts bounding the basin from both sides suggests a relatively high degree of tectonic activity. The mountain front sinuosity (S mf ) generally varies from 1.1 to 1.3 in both sides of the basin suggesting the active fronts and facet slopes (12°-32°) suggest a relatively high degree of activity along the both sides of the Kemalpaşa Basin. Similarly, the valley floor width-to-height ratios (V f ) obtained from the both sides indicate low values varying from 0.043 to 0.92, which are typical values (<1) for tectonically active mountain fronts. The all values obtained are lower for the southern side. Therefore, we suggest that the tectonic activity of the Kemalpaşa Fault higher than the Spildağı Fault Zone. This difference that can be arised from the different uplift rates also reveals the typical asymmetric characteristics of the Kemalpaşa Basin. Additionally, the trapezoidal facets which have been observed on the southern side of the basin indicate that the Kemalpaşa Fault is evolutionally more active as compared to the Spildağı Fault Zone. The geomorphic indices indicate that the Quaternary landscape evolution of the Kemalpaşa Basin was governed by tectonic and erosional processes, and also the all results of morphometric analysis suggest a relatively high degree of tectonic activity along the faults bounding the Kemalpaşa Basin. Moreover, considering that active large normal faults with an average 15 km long can cause major earthquake, the earthquake hazard in the Kemalpaşa Basin should be investigated in detailed paleoseismological studies.

Geomorphic evidence for active tectonic deformation in the coastal part of Eastern Black Sea, Eastern Pontides, Turkey

“…The methods applied to the study of drainage basins are sensitive to active faulting and tectonics, especially uplifting areas. Analyses such as, mountain-front sinuosity, drainage basin shape, stream channel asymmetry, and stream length gradients, are tools for analyzing the tectonically active areas (Bull, 1977;Bull & McFadden, 1977;Gürbüz & Gürer, 2008;Keller, 1986;Keller & Pinter, 2002;Özkaymak, 2015;Özkaymak & Sözbilir, 2012;Ramírez-Herrera, 1998;Silva, Goy, Zazo, & Bardajı, 2003;Tepe & Sözbilir, 2017;Troiani, Galve, Piacentini, Della Seta, & Guerrero, 2014;Wells et al, 1988;Yıldırım, 2014).…”

Tectonic geomorphology of Bozdoğan and Karacasu grabens, western Anatolia

“…The high erosion rates observed in the western blocks of both grabens may show that the deformation changes along the fault segments are related with the strike of the segments forming the southeastern curvature. These uplift rates are compatible with the middlelate Pliocene uplift rates (0.2-0.3mm/yr) suggested for the Western Anatolian Extensional Province (Demir et al, 2004), the Pliocene-Quaternary uplift rates in the Büyük Menderes region (0.1-0.2mm/yr, Westaway et al, 2003), and the uplift rates in the southern part of Denizli Graben (0.15-0.38mm/yr, Özkaymak, 2014), Çameli Basin (0.05-0.5mm/yr, Özsayın, 2016), Kemalpaşa Basin (0.1-0.5mm/ yr, Tepe and Sözbilir, 2017), Priene-Sazlı Fault of Söke Basin (0.05-0.5mm/yr, Topal, 2019a) and in the Çamköy and Yazır segments of the KG (0.05-0.5mm/yr, Topal, 2019a).…”

Neo-Tectonism and Quantitative Morphotectonic Analysis of Roste Valley at Imbricated-Suture Zones, Kurdistan Region, Iraq

“…where Bl is the length of the basin measured from head-water to river mouth, Bw is the width of the basin measured from the widest portion of the basin, the high value represents the elongated basin associated with the high tectonism, whereas the low value indicates the circular basin and low tectonic activity (Tepe and Sözbilir, 2017;Keller and Pinter, 1996). Bs are classified into the following classes: Class 1 (Bs ≥ 1.77) elongate basin with high active tectonism; Class 2 (1.76 ≥ Bs ≥ 1.21) moderate tectonism associated with elongate to circular basins and Class 3 (Bs ≤ 1.20) Low tectonic activity with circular basins (Mahmood and Gloaguen, 2012) (Table 5) (Fig.…”