Landform Matching and Evaluation of Tectonic and Seismic Tensions in the Northern Section of Qom-Zefreh Fault Zone

Document Type : Full length article

Authors

1 Professor of Geomorphology, Faculty of Geography, University of Tehran, Tehran, Iran

2 Associate Professor of Geomorphology, Faculty of Geography, University of Tehran, Tehran, Iran

3 Associate Professor of Geology, Faculty of Geography, University of Tehran, Tehran, Iran

4 PhD Student in Geomorphology, Faculty of Geography, University of Tehran, Tehran, Iran

Abstract

Introduction
The faults of the northern section of Qom-Zafreh faulting system with right-lateral right-angled movements, along with reversed components configure the northern parts of the central Iran zone. In this research, seismic potential and tectonic stresses of this fault system are investigated based on geomorphometric and morphotectonic methods. Field data and morphotectonic evidence in the area have been used to analyze the data. To this end, were measured some geomorphic indices and their adaptation to the location of the main faults. These indicators, as the most widely used in the tectonics and neotectonic evaluation studies, are considered as the first category. The second category is the indices related to the catchment basin dynamics. On the one hand, the characteristics of the mentioned indices are sensitivity to the movements of sliding and steady-state faults and, on the other hand, the reason for the predominance of deformed phenomena in relation to the erosion in the region. To calculate geomorphic indices in 18 sub-basins in the study area, the TecDEM extension program was also used. The initial results indicate the high tectonic activity near the main faults of the northern part of the Qom-Zafare zone such as Bidadeh fault, Qom fault, Kashan fault, and other faults.  These findings are consistent with landforms and tectonic activities existing in the region. 
Materials and methods
In this research, the seismic potential and tectonic activity of the northern section of the Qom-Zafare fault system have been evaluated using geomorphometric and morphotectonic methods in the sub-basins of the study area. In order to investigate the tectonic activity, the study area was divided into 18 sub-basins. Then, to measure and evaluate the tectonic activities of the study area, we measured geomorphic indices and their adaptation to the location of the main faults.
In order to calculate the geomorphic indices of the study area, they were classified into two general categories: 1) Dynamic indicators of the surface including longitudinal gradient (SL), sine wave of the mountain front (Smf) and ratio of valley width to valley height (Vf). 2) Dynamic catchment indicators of the catchment area including drainage basin asymmetry (AF), hypsometric integral (Hi) and drainage basin shape (Bs). To improve the quality of measuring the tectonic and neotectonic indices, the computational capability of the TecDEM software, as an add-on, has been employed in the Matlab software environment. After extraction, the results of the geomorphic indices were separated into ArcGIS environment by separating study basins of each study area and to obtain the tectonic activity index (Iat). Based on the obtained values ​​from the active land development index (IAT), the five study areas were very active, active, moderate, and low activity and very low activity.
Results and discussion
The study area includes the northern section of Qom-Zefreh fault zone, which includes a large part of the Qom province. This zone extends from the east and south-east to the Central Iran and from the north to the Alborz zone and from the west and southwest to Sanandaj Zone of Garrison.
In general, there are active tectonic processes and seismic faults in the northwest-southeastern region. Measurements and investigation of the evidence of the activity of faults in quaternary sediments indicate the change in the process of these faults and cause the alteration of these faults to be generally right-angled, although the left-handed movements in some of the secondary or non-essential faults are due to their orientation in relation to the main stress.
Conclusion
In order to conclude and evaluate the seismic potential and tectonic activity in this part of the Qom-Zefref fault zone, these indicators are divided into two general categories: dynamic indicators of catchment basins, then by the relative activity index Iat. They were classified into three categories. Finally, by integrating the Iat index layer and other information layers, including the deformation of the main faults and the intensity of seismic centers in the ArcMap10.3 software environment, based on seismicity and tectonic activity, we determined five classes of very low, low, moderate, high and very high. By the way, we extracted the seismic potential zonation map and tectonic activities of the study area. In this research, for the first time, geomorphic indices are used for zonation of seismicity and tectonic activities in terms of the relative tectonic activity index of Iat, in contrast to other studies only used geological parameters (lithology).

Keywords

Main Subjects


اعظم مابقی، س. و حسین‏زاده، س.ر. (1396). تجزیه ‏و تحلیل تکتونیک‏– ژئومورفولوژی حوضة رودخانة درونگر، مجله جغرافیا و توسعه، ۴۹: 163-188.
باقری، سجاد (1388). بررسی نقش تکتونیک در شکل‏گیری و تحول لندفرم‏های طاقدیس قلاجه (استان کرمانشاه)، پایان‏نامة کارشناسی ارشد، دانشکدة جغرافیای دانشگاه تهران.
بهرامی، ش.؛ تقوی مقدم، ا. و زنگنه اسدی، م.ع. (1396). کارایی شاخص‏های ژئومورفومتری شبکة زهکشی جهت ارزیابی تکتونیک فعال در حوضه‏های باغرود، بوژان، زاوین، و سررود در شمال شرق کشور، مجلة آمایش جغرافیایی فضا، فصل‏نامة علمی- پژوهشی دانشگاه گلستان، ۷(۲۵).
ده‏بزرگی، م. و مؤمنی طارمسری، م. (1395). فعالیت زمین‏ساخت جوان در پهنه گسلی قم‏– زفره ایران مرکزی، پژوهش‏های ژئومورفولوژی کمّی، ۵(۲): 110-129.
سایت پژوهشگاه بین‏المللی زلزله‏شناسی و مهندسی زلزله: http://www.iiees.ac.ir(IIEES)
قربانی، ا.؛ دولتی، ا. و پورکرمانی، م. (1394). ارزیابی میزان جنبایی زمین‏ساختی و پویایی گسل‏های شمال باختری گسترة ایران مرکزی، پهنة قم- ساوه، فصل‏نامة کواترنری ایران، ۱(۴): 293-306.
گورابی، ا. و کیارستمی، ف. (1394). ارزیابی زمین‏ساخت حوضه‏های آبریز با استفاده از اختصاصات ژئومورفولوژیک در قالب الگوی TecDEM مورد مطالعه: حوضة آبریز رودک در شمال شرق تهران، مجلة پژوهش‏های جغرافیای طبیعی، 47(۳): ۴۶۵-479.
محمدنژاد، و. (1395). گسل‏های فعال و تأثیر آن‏ها بر تغییر شکل لندفرم‏های کواترنر شمال‏ شرق دریاچة ارومیه، ایران، پژوهش‏های جغرافیای طبیعی، ۴۸(۱): 83-106.
Azam Mabaghi, S. and Hosseinzadeh, S.R. (2017). Tectonic-Geomorphological Analysis of the Darongar River Basin, Journal of Geography and Development, 49: 163-188.
Bagheri, S. (2009a). Investigating the role of tectonics in the formation and transformation of the altogether of Taqdis Qalajeh (Kermanshah province), Master's thesis, Faculty of Geography, Tehran University.
Bagheri, S. (2009b). Investigation of the role of tectonics in the formation and evolution of the Ghalajeh anticline landforms (Kermanshah province), M.Sc., Faculty of Geography, University of Tehran.
Bahrami, Sh. (2013). Analyzing the drainage system anomaly of Zagros basins: Implications for active tectonics, Journal of Tecnophysics, pp. 914-928.
Bahrami, S.; Taghavi Moghaddam, E. and Zanganeh Asadi, M.A. (2017). Efficiency of Geomorphometric Indices of Drainage Network for Active Tectonic Assessment in Baghroud, Bojan, Zavin and Sarrood Basins in Northeast of Iran, Journal of Geographical Planning of Space, Scientific Journal Golestan, 7(25).
Bull, W.B. and Mcfadden, L.D. (1977). Tectonic geomorphology north and south of the Garlock fault, California, Geomorphology in arid regions. Proc. 8th Binghamton symposium in geomorphology, 977: 115-138.
Burbank, D. W. and Anderson, S., 2001, Tectonic Geomorphology. Blackweel Science, Massachusetts.
Deh Bozorgi, M. adn Momeni Taramsari, M. (2016). NeoTectonic Activity in the Qom-Zefra Fault Zone of Central Iran, Quantitative Geomorphological Research, 5(2): 110-129.
Ghorbani, E.; Dowlati, A. and Pourkermani, M. (2015). Assessment of Tectonic Kinetic and Dynamics of Northwest Fault of Central Iran Range, Qom-Saveh Zone, Iranian Quaternary Quarterly, Volume 1, Number 4, Winter 2015, pp293-306.
Gorabi, A. and Kiarostami, F. (2015). Tectonic Evaluation of Watersheds Using Geomorphological Properties in the TecDEM Model Study: Rudak Basin in Northeast of Tehran, Journal of Geographical Research, 47: 465-479.
Hessami, K.; Jamali, F. and Tabassi, H. (2003). Major active faults of Iran, scale 1: 2,500,000. International Institute of Earthquake Engineering and Seismology.
Keller, E.A. and Pinter, N. (2002). Active tectonics: Eathquake Uplift, and Landscape, Prentic Hall, Newjersey.
Moghimi, E. (2009). Comparative Study of Changing Drainage Basin System with Tectonic Forms, Case Study: Lut Block, Iran, American Journal of Applied Sciences, 6(6): 1270-1276.
Mohammadnejad, V. (2016). Active faults and their effect on the deformation of Quaternary landforms northeast of Urmia Lake, Iran, Journal of Natural Geography Research, 44(1): 24-106.
Morley, C.K.; Kongwung, B.; Julapour, A.A.; Abdolghafourian, M.; Hajian, M.; Waples, D.; Warren, J.; Otterdoom, H.; Srisuriyon, K. and Kazemi, H. (2009). Structural development of a major late Cenozoic basin and transpressional belt in central Iran: the Central Basin in the Qom-Saveh area, Geosphere, 5(4): 325-362.
Mumipour, M.; Rezaei-Moghaddam, M.H. and Khorshiddoust, A.M. (2012). Active Tectonics Influence On Drainage Networks In Dinarkooh Region, Zagros Mountain Range, Iran, Geografia Fisica e Dinamica Quaternaria, 35: 61-68, 8 figg., 3 tabb. DOI 10.4461/GFDQ.2012.35.6.
Hamdouni, R.El.; Irigaray, C.; Fernández, T.; Chacón, J. and Keller, E.A. (2008). Assessment of relative active tectonic, south west border of the Sierra Nevada (Southern Spain), Geomorphology, 96:150-173.
Rockwell, T. K., Keller, E. A. & Johnson, D. L., 1985, Tectonic geomorphology of alluvial fans and mountain front near Ventura, California. In: Morisawa, M. (Ed), Tectonic geomorphology. Proceedings of the 15th Annual Geomorphology Symposium. Allen and Unwin Publishers, Boston, MA, pp. 183-207.
Shabir Ahmad, Akhtar Alam, Bashir Ahmad , Ahsan Afzal , M.I. Bhat , M. Sultan Bhat , Hakim Farooq Ahmad (2018). Tectono-geomorphic indices of the Erin basin, NE Kashmir valley, India, Journal of Asian Earth Sciences, 151:16–30.
Shahzad, F. and Gloaguen, R. (2011a). TecDEM: A MATLAB based toolbox for tectonic geomorphology, Part 1: Drainage network preprocessing and stream profile analysis, Computers & Geosciences, 37: 250-260.
Shahzad, F. and Gloaguen, R. (2011b). TecDEM: A MATLAB based toolbox for tectonic geomorphology, Part 2: Surface dynamics and basin analysis, Computers & Geosciences, 37: 261-271.
Silva, P. G., Goy, J, L., Zazo, C. & Bardajm, T., 2003, Fault generated mountain front in Southeast Spain: geomorphologic assessment of tectonic and earthquake activity. Geomorphology, 250, 203-226.
Site of International Institute of Seismology and Earthquake Engineering, http://www.iiees.ac.ir (IIEES).