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

Abstract

The Eastern Pontides (EP), which is the under transpressional deformation zone, is an active mountain belt that has been rising rapidly since the Cenozoic era because of the Arabian-Eurasian convergence. Morphometric studies have been performed to investigate the tectonic activity of this region and better understand the characteristics of the faults geomorphologically; the faults control the mountain fronts in the drainage basin of the EP. The results show the Hypsometric Curve (HC)-Hypsometric Integral (0.37-HI-0.67), Basin-Shaped Analysis (1.2-B s-7), Valley-Floor-Width to Height-Ratio (0.4-V f-1.2) and Asymmetry Factor (35-AF-81) applied to 46 drainage basins together with 9 tectonically controlled geomorphic indices (1.2-S mf-1.5) and a Stream Length Gradient (30-S L-120) indicate that the EP is tectonically active, and when the areas are evaluated according to S mf and V f analyses, the tectonic level is relatively high. According to our conceptual model for the uplifting of the EP, with respect to field studies and morphometric analysis, (i) the EP is the active deformation zone and has a "push-up" geometry in conjunction with the North Anatolian Fault; (ii) the EP is progressively uplifting at a rate of more than 0.5 mm/yr in along with the thrust faults of the Black Sea Fault (BSF) and Borjomi-Kazbegi Fault (BKF).

Yeşilırmak Havzası Yukarı Mecrasında Almus Fayı Boyunca Drenajın Gelişimi

“…High SL values further suggest that development of the sub-basins was controlled by recent tectonic activity in the study area. A similar result was also found in Softa et al (2018)'s study. Their results indicated that each river has a knickpoint which marked fault zones determined in the area.…”

“…This shows that the zone is tectonically active in the Eastern Pontides. At the same time, high SL values and those having knickpoints show that the drainage basins analyzed are in disequilibrium and the ephemeral feature of the area is due to incomplete uplifting (Softa et al, 2018). In the southern sector, the SL values of the Korucak stream are greater than the other streams.…”

“…Both the morphological analyses and rate of uplift suggest that the coastal section of the Eastern Pontides is highly active. (Softa et al, 2018).…”

“…In recent years, studies on investigating active tectonic deformation using quantitative geomorphology have increased. Geomorphic indexes such as the valley width/height ratio, mountain front sinuosity, drainage basin asymmetry and river length-gradient were used to assess the drainage pattern evolutivon and to describe the effects of tectonism on the morphology of drainage basins along the NAFZ in the region surrounding the study area by some of the researcher (e.g., Tüysüz and Erturaç, 2005;Selim et al, 2013;Gürbüz et al, 2015;Khalifa et al, 2018;Softa et al, 2018) and in other parts of the world (Kirby and Whipple, 2001;Harkins et al, 2005;Wobus et al, 2006;Bahrami, 2013;Das et al, 2013;Siddiqui, 2014). The tectonic settings are related to NAF producing various subsidence basins.…”

Tectonic Geomorphology

“…New faults were also identified based on field observations, Hack profile, and SL-indices in Chitwan dun, central Nepal. OSL dating derived ages of the landforms support distinct climate-tectonic coupling events responsible for landscape evolution in Chitwan dun García-Delgado and Velandia (2020) Structural and geomorphic indices-based study indicates greater tectonic activity and uplift rates for the northern San Lucas Range, in the Northern Andes Transform setting Arrowsmith and Zielke (2009) Field evidences, paleoseismic analysis, and high-resolution LiDAR DEM were used to trace the active Cholame segment of San Andreas Fault (SAF) to understand tectonic geomorphology of SAF Softa et al (2018) Transpressional deformation zone, the Eastern Pontides (EP), is the active deformation zone and has a "push-up" geometry in conjunction with the North Anatolian Fault high. The EP exhibits high tectonic activity based on geomorphic indices and more than 0.5 mm/yr upliftment along the thrust faults of the Black Sea Fault (BSF) and Borjomi-Kazbegi Fault (BKF) in the active mountain belt…”