Document Type : Original Paper


Department of Geology, Faculty of Basic Sciences, Tarbiat Modares University, Tehran, Islamic Republic of Iran


Suture zones within continental collision zones generally considered as deep-seated thick-skinned thrusts/shear zones rotted in lower crust. Main Zagros Revers Fault (MZRF) is the suture zone for continental collision between the Afro-Arabia and Eurassia plates. The fault comprises of a main thrust in its NW part (Baneh area) while is partitioned to four fault splays in its SE part (Sharekord area). Evaluation of deformation conditions of the MZRF fault rocks carried out using quartz, feldspar and calcite twins’ microstructures as well as mineral composition indicates that the fault has propagated from various conditions correspond to different brittle to brittle-ductile transition zones. This implies localization and partitioning of deformation along strike of the Zagros suture zone. In the Baneh area, the suture zone is an emerged deep-rotted ductile zone, while in the Shahrekord area, this zone is detached at a basal detachment zone between basement and cover and then partitioned into four fault splays through its propagation to the upper structural level. This show that suture zones in orogenic belts might have changes along strike from thick-skinned to thin-skinned thrusts.


Main Subjects

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