Detecting a Sinistral Transpressional Deformation Belt in the Zagros

Mohammad Ali Ghanbarian,Reza Derakhshani,Ali Yassaghi

doi:10.3390/geosciences11060226

Mohammad Ali Ghanbarian, Reza Derakhshani + Show 1 more

Open Access

https://doi.org/10.3390/geosciences11060226

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Abstract

The oblique collision between the northeastern margin of the Arabian platform and the Iranian microcontinent has led to transpressional deformation in the Zagros orogenic belt in the central part of the Alpine–Himalayan orogenic belt. Although previous articles have emphasized the dextral sense of shear in the Zagros orogenic belt, in this paper, using several indicators of kinematic shear sense upon field checking and microscopic thin-section studies, evidence of the development of a sinistral top-to-the NW deformation belt is presented. The mean attitudes of the foliations and lineations in this belt are 318°/55°NE and 19°/113°, respectively.

Highlights

From a tectonic point of view, Iran includes several geological zones, including the Zagros, Central Iran, Alborz, and the east and southeast of Iran, in some of which there are some sub-zones and belts such as Makran, Lut, Sistan suture zone, Urumieh–Dokhtar magmatic belt, and Sanandaj–Sirjan Zone (SSZ)
Understanding the kinematics of the Zagros transpressional belt is important to constrain the tectonic development of this part of the Alpine–Himalayan orogenic system
This means that this orogen is one of the most studied and known collision belts [2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27]. This belt has been formed by NE-dipping subduction of Neo-Tethys under the Iranian microcontinent in the Jurassic to Paleogene followed by the subsequent oblique collision of the central Iran microcontinent and the Arabian platform in the Neogene (Figure 1) [2,28,29] where post-collisional crustal shortening is still active today [30,31,32,33]

Summary

Introduction

From a tectonic point of view, Iran includes several geological zones, including the Zagros, Central Iran, Alborz, and the east and southeast of Iran, in some of which there are some sub-zones and belts such as Makran, Lut, Sistan suture zone, Urumieh–Dokhtar magmatic belt, and Sanandaj–Sirjan Zone (SSZ). Understanding the kinematics of the Zagros transpressional belt is important to constrain the tectonic development of this part of the Alpine–Himalayan orogenic system. This means that this orogen is one of the most studied and known collision belts [2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27]. The fabric of Heneshk (Kowlikosh) shear zones (Figure 2 in [14]) and Neyriz area (Figure 3 in [1])

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Conclusion