Investigation of active tectonics related to Zardkooh fault and Nazi Bazaft salt dome using geomorphic indicators, southwestern Iran

Khodadadi, Gholamreza; Ahnkoob, Maryam

doi:10.22034/irqua.2022.702441

Investigation of active tectonics related to Zardkooh fault and Nazi Bazaft salt dome using geomorphic indicators, southwestern Iran

Document Type : Original Article

Authors

Gholamreza Khodadadi ¹

Maryam Ahnkoob ²

¹ Bo Ali Sina University, Hamadan, Iran

² Payam Noor University, Tehran, Iran

https://doi.org/10.22034/irqua.2022.702441

Abstract

Nazi salt dome is located in the border of high Zagros and folded Zagros in the northwest of Chaharmahal Bakhtiari province. This dome is affected by Zardkooh fault in the heights of Zard Kooh. The sequence of formations in the region includes Infra-Cambrian sedimentary rocks up to the present time The aim of this study was to investigate the active tectonics associated with Zardkooh fault and Nazi salt dome in Bazaft area in Chaharmahal and Bakhtiari province, using morphometric indices. Zardkooh fault is the border of high Zagros and folded Zagros. Zardkooh fault and Nazi salt dome are both exposed on the ground. In order to study the tectonics of the study area, the study area was first divided into 59 basins Then quantitative morphometric indices such as hypostometric integral index (Hi), drainage basin asymmetry index (Af), river gradient index (SL), basin shape index (BS), mountain front sinusitis index (Smf), relatively active tectonics index (Iat) has been calculated. In Hi index, 7 basins with active new tectonic activity, 21 basins with moderate tectonic activityand 31 basins with low tectonic activity were identified. Also in Af index, 18 basins with high and activetectonic activity, 21 basins with medium tectonic activity and 20 basins with low tectonic activity were determined. One high-activity basin, two basins with moderate tectonic activity and 56 basins with low tectonic activity were identified in the SL index. In BS index, 2 basins with active tectonic activity, 2 basins with moderate tectonic activity and 54 basins with low tectonic activity were identified. In Smf 16 index, the basin has active tectonic activity and the rest of the basins have low to very low tectonic activity. Relative activity index (IAT) in the study area indicates the presence of 3 basins with active tectonic activity, 26 basins with moderate tectonic activity and 30 basins with low tectonic activity are low. Based on the calculated indicators, the study area has different basin activities from medium to low. The data show that the activity of Zardkooh fault, the activity of the Nazi salt dome, large waterways in the region, and vegetation in the region have a significant impact on the activities of the region. The area has moderate to low new construction activity.

Keywords

Tectonics

Folded Zagros

High Ragres

Zardkooh Fault

Salt Dome

Nazi

Bazaft

20.1001.1.24237108.1400.7.2.8.6

Subjects

Neotectonics and faults

آهنکوب، م.، مردانی، گ،. طباطبایی، س.ح،. و هادی پور، ز، 1400، بررسی وضعیت هیدروژئوشیمیایی آبخوان دشت خانمیرزا در ارتباط با سازندهای زمین‌شناسی (استان چهارمحال و بختیاری)، مجله یافته های نوین زمین شناسی .

باقری. ح، 1395. گنبدهای نمکیف انتشارات نظری، 120 صفحه.

بیاتی خطیبی.م، 1388. تشخیص فعالیت‌های نئوتکتونیکی در حوضه آبریز قرنقوچای با استفاده از شاخص‌های ژئومورفیک و مورفوتکتونیک مجله علمی- پژوهشی فضای جغرافیایی، سال نهم، شماره ی2، بهار 1388،ص.23-50.

شعبانیان، ر.، 1391 (چاپ اول). زمین شناسی ایران، انتشارات دانشگاه پیام نور.

غ، خدادادی:1399. شواهد زمین ساخت فعال مرتبط با گنبد نمکی چلگرد، باختر ایران، پایان نامه کارشناسی ارشد.

Ambraseys, N.N. Melvelli, C.P.1982. A History of Persian Earthquake. Cambridg University Press.

Bahroudi, A., 2003. The effect of mechanical Characteristics of basal decollement and basement structures on deformation of the Zagros basin. Acta Universitatis, Comprehensive Summaries of Uppsala Dissertation from the Faculty of Science and Technology 836, 43 pp, Uppsala, ISBN 91-554-5621-9.

Berberian, M., 1995, "Master blind thrust fault hidden under Zagros fold: active basement tectonics and surface morphotectonic", Tectonophsics, 241 (3-4): 193-195.

Bull,W.B. and Mcfadden, L.D.,1977. Tectonic geomorphology north and south of the Garlock fault, California, In: Doehring, D. O.(Ed)., Geomorphology in Arid Regions, Proceedings of the Eighth Annual Geomorphology symposium, State University of New York, and Binghamton,.115-138.

Canon, P. J., 1976, Generation of explicit parameters for a quantitative geomorphic study of Mill Creek drainage basin. Oklahoma Geology Notes, 36(1), 3-16.

El Hamdouni, R., Irigraay, C., Fernandez, T., Chacan,J., keller, E.A.,2007. Assessment of relative tectonics, southwest border of Sierra Nevada(southern Spain) Geomorphology 96, 150-173.

El Hamdouni, R., Irigaray, C., Fernandez, T., Chacan,J., Keller, E.A. 2008. Assessment of relative tectonics, southwest border of Sierra Nevada (southern Spain) Geomorphology, 96, 150-173.

Hack,J.T.,1973. Stream-profile analysis and stream-gradient index, U.S. Geological Survey Journal of Research,1, 421-429.

Humber, H., 1977. Geological Map of Iran, Scale 1:1000000 with Explanatory Note, NIOC., Explor. Prod., Tehran.

James, G. A., Wynd, J. G., 1965. Stratigraphic Nomenclature of Iranian Oil Consortium Agreement Area: Bulletin of the American Association of Petroleum Geologists, 2182-2245.

Keller, E.A. and Pinter,N,.1996. Geomorphic inedices provide relative elvation of tectonic activites in a basin.

Keller E.A, and Pinter, N,. 2002. Active Tectonics Earthquake Uplift, and Landscape, Prentice Hall Newjersey.

Mohajjel, M. and Fergusson, C. L. 2014. Jurassic to Cenozoic tectonics of the zagros orogen in northwestern Iran. International Geology Review, 56(3), 263-287.

Nemati, M. and Yassaghi, A., 2010. Structural characteristics of the transitional zone frome internal to external parts of the Zagros orogen,Iran. Asian Earth Sciences 39, 161-172.J.

Pick, R.J., Wilson, S. E., 1971. Elvation – relief ratio, hypsometric integral and geomorphic area-altitude analysis. Geological Society of America Bulletin, Vol. 82, PP. 1079-1084.

Ramirez, M. and Herrera, M. T.(1998). "Geomorphic assaessment of active tectonics in the Acambay Graben, Mexican volcanic belt". Earth Surface Processes and Landforms, Vol. 23,pp.317-332.

Sepehr, M., and Cosgrove, J.W., 2004. Structural framework of the Zagros Fold Thrust Belt, Iran Marine and Petroleum Geology, 26, 829-843.

Talebian, M. and Jackson, J. 2002. "Offset on the Main Recent Fault of the NW Iran and Implication for the Late Cenozoic tectonics of the Arabia-Eurasia collision zone", Geophys. J. Int,. 150, 422- 439.