The nature and movement of thrusts in the eastern Iranian orogen: Sechengi Area on the northern border of Lut and Sistan

Abstract

The eastern Iranian range, known as the Sistan suture zone in the past, has recently been identified as the Sistan orogen. This paleogene orogeny is located between the Lut and Afghan microcontinents. The structural analysis shows that most of the thrusts dip towards the NW so that the Permo-Triassic sediments and Jurassic micro-diorites of the Lut Block overthrusted over the younger rocks. Structural studies show that the tectonic vergence was from the NW to the SE of the Sechengi area in the NW part of Sistan orogen. We recognized three deformation phases in eastern Iran. The first N-S deformation event (D1)resulted in the formation of tight E-W folds (F1) and associated cleavages (S1). The second E-W deformation event (D2), which occurred in the late Paleogene led to the bending of older structures, including the axial plane of the first-generation folds giving them a new northwest direction (F2).