Tectonics movements of Kuhbanan fault system in Bahabad region, Central Iran

Iranian Journal of Earth Sciences

مقاله 7، دوره 1، شماره 1، دی 2009، صفحه 92-98   

نوع مقاله: Original Research Paper

نویسنده

A. Shafiei Bafti^*

Islamic Azad University, Zarand Branch, Iran

چکیده

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.

کلیدواژه‌ها

active tectonics؛ Geomorphic indices؛ Drainage reconstruction؛ Cumulative displacement؛ slip rate؛ Kuhbanan fault system