Author

Department of geology, Khoy branch, Islamic Azad University, Khoy, Iran.

Abstract

Morphotectonic investigations were carried out by the use of morphometric indices which serve as a tool of identification in regions with active tectonic warp. Landforms in active deformation area are produced from relations of tectonic and surficial processes. One of the most significant landforms underground is rivers that are extremely responsive to tectonic movements mainly uplift and tilting. Accordingly, based on investigation of the rivers and interrelated drainage networks by the use of morphometric indices, we will be able to achieve valuable information about tectonic record of the study area. In this study, in order to find out the tectonic activities of the study area, geomorphic indices were surveyed in Garehbagh basin. In order to determine tectonic movement of Garehbagh basin area, six different morphometric indices including Mountain Front Sinuosity (Smf), Valley Floor Width to Height Ratio (Vf), Index of drainage basin shape (Bs), Stream Length Gradient Index (Sl), Hypsometric integral (Hi), Drainage basin asymmetry (Af) were applied to the study area. According to generated results, SL values change between Smf value according to generated outcome; the most active mountain fronts faults of the study area.. Deep and narrow valleys show low Vf values <1.0, these valleys can be classified as V-shaped valleys and Vf values between 1 and 1.5  indicate moderately active regions and Vf values greater than 1.0 can be classified as ―U‖ shaped valleys. According to generated outcome, in the study area, the Hi value is 0.86. High values of the hypsometric integral specify deep incision and rugged relief. Intermediate low values of the integral are related with more evenly dissected drainage basins. Asymmetry factor extensively greater than 50 suggest tectonic tilt. Results from the analysis are accumulated and expressed as an index of relative active tectonics (Iat), which is divided into one class from relatively high tectonic activity. The study area relatively high rates of active tectonics are associated with indicative values of Iat.

Keywords