Quantitative assessment of the relative tectonic activity using the analytical hierarchy process in the northwestern margin of the Lut Block, Central Iran

• Published in: Journal of Asian earth sciences Vol. 206; p. 104607
• Main Authors: Moumeni, Mohammad, Nozaem, Reza, Dehbozorgi, Maryam
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.02.2021
• Subjects: Active tectonics; Analytical Hierarchy Process; Central Iran; Kuh-e-Sarhangi Fault; Lut Block; Morphotectonic; Active tectonics; Kuh-e-Sarhangi Fault; Central Iran; Lut Block; Analytical Hierarchy Process; Morphotectonic
• ISSN: 1367-9120; 1878-5786
• DOI: 10.1016/j.jseaes.2020.104607

[Display omitted] •The accuracy of Iat map and its classes improved by the AHP method.•Regions with high tectonic activities conform to the deformed post-Neogene units.•Paleostress results show WNW-ESE trend for maximum principal stress (σ1).•Kuh-e-Sarhangi fault has been active since Neogene in a dextral strike-slip regime.•The basement faults in the study area were reactivated during Neogene. In this study, the analytical hierarchy process (AHP) was used to enhance the accuracy of the results obtained from the geomorphic analysis of tectonic activity. For this purpose, the relative tectonic activity index was computed by applying different and specific weights to each index based on the general geological and structural conditions of the study area. The Kuh-e-Sarhangi Mountain with a NE-SW strike is located in the northern part of the Tabas Block in the Central Iran Plate. The Kuh-e-Sarhangi Fault is considered one of the major faults in Central Iran and shows evidence of Quaternary activity. In this study, in order to evaluate the activity of the faults, six morphotectonic indices were computed and the different conditions which influenced the morphometric factors were considered and analyzed. The relative tectonic activity of Kuh-e-Sarhangi was classified based on the analytical hierarchy process method. These results were confirmed by field studies. The results of this method fitted well with some independently detected Quaternary faults and other reactivated faults in the Kuh-e-Sarhangi Mountain. With a right-lateral movement, some of these faults have caused the displacement of rivers up to 900 m. The dispersal of the high tectonic activity classes based on the AHP method conforms to the post-Neogene activity of the region. The distribution of the classes illustrates that morphotectonic anomalies correspond with the incised alluvial fans and terraces and the bisected and displaced rivers in the study area. Accordingly, the integration of the results of field investigations, satellite images, morphometry, and the AHP method shows a high accordance with the active structures and demonstrates that the study area is tectonically active. This analysis illustrates the recent movements of the Kuh-e-Sarhangi Fault and the activity of the Lut Block due to the convergent movement of the Arabian plate toward Eurasia.