Evidences and Structural analysis in the high Zagros collision (Sahneh - Harsin)

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1 a

2 smc

3 MSc

Abstract

Abstract
The study area is located between high Zagros and S-S zones. The main Stratigraphy units in the study area are comprised of Volcanic-Sedimentary Sequence, Mesozoic and Cenozoic limestones. The main structures in this area are oriented in NW-SE, to the main Zagros thrust direction. Most of radiolarites have sharp hinge, chevron folds and their interlimb angles are about 30° - 70º. In Shahabad olya area radiolarites have been strongly folded and faulted in which faulting happened after folding. These radiolarites do not have an interface and they show refolding evidences. Accordingly, it seems that in this situation radiolarites are klippe. Mesozoic major foldings (in limestone) have a rounded hinge and NW-SE direction, but in some folds the evidences of refolding are visible. Cenozoic foldings of this area have rounded hinge and their interlimb angle is 120°. Also, according to ((Π diagram, most of these foldings are cylindrical with NW-SE axial surface direction. Elements of fold in these units are different so that reasons are differential rheology and formed folds in different tectonic phases. Mesozoic limestone are thrusted on ophiolites is a reason for formed duplex structures.Study of calcite twin morphology and grain size recrystallization demonstrate that deformation condition in this area have intermediate deformation zone peroperties and deformation temperature reduces from outer part to inner part. The average amount of flow stress is 200 to 300 Mpa.

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منابع
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Journal of Tectonics
Volume 1, Issue 3
October 2015
Pages 73-96

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