Active tectonics analysis based on morphometric indices; case study of Agh Chay watershed in NW Khoy


Department of Geology, Khoy Branch, Islamic Azad University, Khoy, Iran


The study of Tectonic activity, and in particular those earas with relatively high activity in the Holocene and late Pleistocene is important to evaluate the earthquake hazard. The purpose of this study is to investigate the role of tectonic factors in the development and morphological changes of the alluvial fans of Agh Chay. In this study, the topographic maps, geology, satellite photos and the digital elevation model (DEM) were used as the main research data. In addition, the morphology of the alluvial fans of the region was studied closely and through the field study. Then, using the geomorphic indices which includes the sinuosity of the mountain in-front (SMF) Ratio of valley floor width to valley height (VF), Drainage Asymmetry factor (AF), Stream Length-Gradient Index (SL), Transverse Topographic Symmetry Factor (T), Fan Comicality Index (FCI), the region in terms of tectonic activities were assessed. Through combination of these indexes, the index of active tectonics (Iat) can be obtained. The results of study showed that Agh Chay, Zarabad Chay, Dibak Chay and Zavieh Chay have very high activity. Altogether, according to the calculated morphometry indexes, it can be concluded that the region has medium to high tectonic activity, but there are changes in tectonic activity in the region, which can be attributed to increase tectonic activity from north west to south east of the region.


Aghanabati, A., 2004. Major sedimentary-structural units of Iran. Geological Survey of Iran Publications, Tehran.
Alavi-Naini, M., Bolourchi, M.H., 1973. Explanatory text of the Maku Quadrangle Map, Quadrangle A1, and Scale 1:250,000, Geological Survey of Iran, Tehran. 1-44.
Bull, W.B., 2007. Tectonic Geomorphology of Mountains: A New Approach to Paleoseismology. Blackwell, Malden, USA. p.316.
Bull, W.B., McFadden, L.D., 1977. Tectonic Geomorphology North and South of the Garlock Fault, California. In: Doehring, D.O., Ed., Geomorphology in Arid Regions: A Proceedings Volume of the 8th Annual Geomorphology Symposium, State University of New York, Binghamton, 23-24. 115-138.
Chen, Y.C., Sung, Q., Cheng, K.Y., 2003. Along-strike variations of morphotectonic features in the Western Foothills of Taiwan: tectonic implications based on stream-gradient and hypsometric analysis. Geomorphology 56, 109-137.
El-Hamdouni, R., Irigaray, C., Fernández, T., Chacón, J., Keller, E.A., 2008. Assessment of relative Tectonic activity, southwest border of the Sierra Nevada (southern Spain). Geomorphology 96, 150–173.
Garcia-tortosa, F.J., Alfaro, P., Galindo-Zaldivar, J., Gibert, Lopez-Garrido A.C., Sanz de Galdeano, C., Urena, M., 2008. Geomorphology Evidence of the Active Baza Fault (Betic Cordillera, South Spain), Geomorphology 97, 374-391.
Hajgson, R., 1961. Regional study of Jointing in the comb Ridge – Navajo Mountan area, Arizona  and Utah. American Association of Petroleum Geologists 45, 1-38.
Haji Hosseinlou, H., 2017. Morphotectonics Investigation of the Garehbagh basin area based on Morphometric Indices. Iranian Journal of Earth Scinces 9, 105-114.
Haji Hosseinlou, H., Padidar, R., 2015. Shear structures and microstructures analysis in along Aboulfazl thrust, NE Khoy. Advanced Applied Geology 5, 60-76 (in Persian).
Karakhanian, A.S., Trifonov, V.G., Philip, H., Hessami, K., Jamali, F., Bayraktutan, M.H., Bagdassarian, H., Arakelian, S., Davtian, V., Adilkhanyan, A., 2004. Active faulting and natural hazards in Armenia, eastern Turkey and northwestern Iran. Tectonophysics 380, 189- 219.
Keller, E.A., Pinter, N., 2002. Tectonic activity: Earthquakes, Uplift and Landscape, second edition: Upper saddle river, New Jersey, Prentice Hall, p. 362.
Khavari, R., Arian, M., Ghorashi, M., 2009. Neotectonics of the South Central Alborz drainage basin, in NW Tehran, N Iran. Journal of Applied Sciences 9, 4115–4126.
Marzi, S., 2019. Morphotectonics Investigation of the Zarabad (NW Khoy) region based on morphometryIndexes. M.Sc Thesis. University of Islamic Azad University Khoy Branch, Khoy (in Persian).
Mukerji, A.B., 1976. Teminal fans of inlands streams in Sutlej –Yamuna Plain, India. Zeitschrift fur. Geomorphologie 20, 190-204 (in Persian).
Radfar, J., Amini, B., 1999. Geological Map of Khoy, scale 1:100,000. Geological Survey of Iran (in Persian).
Twiss, R.J., Moores, E.M., 2007. Structural Geology. New York: Freeman, W.H. Freeman, p.736.
Ramsay, J.G., Huber, M.I., 1983. The Techniques of Modern Structural Geology, Volume I: Strain Analysis. London Academic Press, p.307.
Zamani, B., Masson, F., 2014. Recent tectonics of East (Iranian) Azerbaijan from stress state reconstructions. Tectonophysics 611, 61–82 (in Persian).