Document Type : Original Research Paper

Authors

1 M. Sc. Student, Department of Geology, Islamic Azad University, Science and Research Branch, Tehran, Iran

2 Assistant Professor, Department of Geology, Islamic Azad University, Science and Research Branch, Tehran, Iran

3 Assistant Professor, Department of Geology, Islamic Azad University, Karaj Branch, Alburz, Iran

4 Assistant Professor, Department of Geography, Tehran University, Tehran, Iran

Abstract

In this paper, the relative active tectonics of the Mordaq-Chai basin has been discussed according to the geomorphic indices using Global Mapper software. The calculated indices are as follows: stream length–gradient index (SL), hypsometric integral (Hi), ratio of valley floor width to valley height (Vf), index of drainage basin shape (Bs),index of mountain front sinuosity (Smf), asymmetry factor (AF), and transverse index of basin topographic symmetry (T). Using above indices results, led to calculation of relative tectonic activity index (Iat).The results show that the Mordaq-Chai basin’s relative tectonic activity index falls into two groups: the first one includes the areas around the Sahand volcano crater (upper part of sub-basin one) and the Goshayesh Valley (upper part of sub-basin three), both of which have high levels of relative tectonic activity. The second one includes high lands located at northern part of the Maragheh fault towards the Kordeh-Deh village (sub-basins one and two), the opening of the Mordaq-Chai river into the Malekan plain (from the Ekiz village to the Sheikh-o-eslam village in central of sub-basin 3) and the southern portion of the Sahand Volcano’s crest (central part of sub-basin one), which all have moderate levels of relative tectonic activity.

Keywords