Moho depth determination beneath the Zagros Mountains from 3D inversion of gravity data
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Due to its geological and economic importance, the Zagros Mountains have been investigated by many researchers during the last decades. Nevertheless, in spite of all the studies conducted on the region, there are still some controversial problems concerning the structure of the Zagros Mountains, including crustal depths, demanding more insights into understanding the crustal constraints of the region. Accordingly, we have conducted a gravity study to determine Moho depth map of the Zagros Mountains region, including its major structural domains from the coastal plain of the Persian Gulf to central Iran. The employed data are the densest and most accurate terrestrial gravity data set observed until now with the precision of 5 μGal and resolution of 5 arc-minute by 5 arc-minute. To image Moho depth variations, gravity inversion software GROWTH2.0 is used, proposing the possibility to model stratified structures by means of a semi-objective exploratory 3D inversion approach. The obtained results reveal the crustal thickness of ~ 30–35 km underneath the southwestern most Zagros Fold-Thrust Belt increasing northeastward to 48 km. The maximum Moho depth is estimated ~ 62 km below the Zagros Mountains belt along the Main Zagros Thrust. Northeast of the study area, an average crustal thickness of 46 km is computed beneath Urumieh–Dokhtar magmatic arc and central Iran.
KeywordsZagros Mountains Moho depth Gravity data 3D inversion
The University of Tehran is acknowledged for the financial support of the first author’s sabbatical leave at AE Consejo Superior de Investigaciones Científicas, CSIC, during the period from March 2016 to August 2016. Research by JF and AGC has been supported by the Spanish Ministry of Economy and Competitiveness research project ESP2013-47780-557 C2-1-R. The Institute of Geosciences (CSIC-UCM) support is appreciated for hosting the first author as the guest researcher. The National Cartographic Center of Iran is also appreciated for providing the data. The first author also thanks Joaquín Escayo and Zeynab Golshadi for their support. It is a contribution to the Moncloa Campus of International Excellence.
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