Kinematic Analysis of the Nain and Darrech Deh Faults and Their Structural Position in the Western Side of the Central Iranian Range

Abstract

The western margin of Central Iran – the Nain area – is composed of the Mesozoic ophiolitic mélanges deposited during the Late Cretaceous. The Nain and Darrech Deh faults whose trace indicators can be seen in the study area are among the largest faults therein. These faults have a north-northwest strike and are the right-lateral transpressional active lineaments. The main aim of this research is to perform structural mapping and geometric analysis of structural features along the Nain and Darrech Deh fault system. The research was conducted using satellite imagery and field data. The structural analysis showed that the faults comprise a complex network which formed during two stages: 1) thrust faulting in the Late Cretaceous and 2) reactivation of thrust faults in the form of the right-lateral reverse-slip structures as a result of transpressional movements in the Upper Miocene. The Nain and Darrech Deh faults are presently active and exhibit the right-lateral strike slip displacement with a reverse component.