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Tectonics movements of Kuhbanan fault system in Bahabad region, Central IranKeywords: Active tectonics , Geomorphic indices , Drainage reconstruction , Cumulative displacement , slip rate , Kuhbanan faul systemt Abstract: Kuhbanan fault system, as one of the intracontinental faults of central Iran, is recognized by considerable seismogenic activities and modern morphotectonics evidences with a strike-slip (reverse component) motion. According to the geometric and kinematics data, Kuhbanan fault has been divided into 5 segments (S26, S27, S28, S29, S30) in Bahabad region. Measured geomorphic indices of ratio of valley-floor width to valley height (Vf) and morphology of the valley (V) manifest the maximum denudation rate for the S28 segment. The mean calculated values of mountain-front sinuosity (Smf) and %facet parameters for different segments of the fault are 1.1 and 83.16, consequently. Regarding to these geomorphic indices, a denudation rate of about 2-4 mmyr-1 is suggested for this region. According to reconstruction of Kuhbanan fault since 360 ka, minimum horizontal cumulative displacement of 750 m and minimum slip rate of about 2-1.4±0.1 mmyr-1 is inferred from well preserved geomorphology in the northern segment of the fault. Applying this horizontal cumulative displacement causes reconstruction of geomorphic markers such as drainages and shuttered ridges.
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