Tectonic controls of the North Anatolian Fault System (NAFS) on the geomorphic evolution of the alluvial fans and fan catchments in Erzincan pull-apart basin; Turkey

The Erzincan pull-apart basin is located in the eastern section of the North Anatolian Fault System (NAFS). The tectonic evolution of this basin is mostly controlled by strike slip master faults of the NAFS. This study examines the topography-structure relationships in an effort to evaluate the tectonic signatures in the landscape, paying special attention to recent tectonic activity. In the study, the main focus is on the tectonic controls of the NAFS on the geomorphic evolution of alluvial fans and fan catchments in the Erzincan pull-apart basin. The observations of the amount of tilting of the alluvial fans (β) and its relation with morphometric (Asymmetry Factor (AF), Hypsometric Integral (HI), Fractal analysis of drainage networks (D)) properties of the fan catchments provide valuable information about the tectonic evolution of the basin area. The results of the analyses showed that the alluvial fan and fan catchment morphology in the pull-apart basin are mainly controlled by the ongoing tectonic activity of the NAFS. The fault system in the basin has controlled the accommodation space by causing differential subsidence of the basin, and aggradation processes by causing channel migration, channel incision and tilting the alluvial fans.