Document Type : Original Research Paper

Authors

• S. Bahiraie ¹
• M. Abbasi ²
• M. Almasian ³

¹ Center for Environment and Energy Research and Studies (CEERS)

² International Institute of Earthquake Engineering and Seismology, Tehran, Iran.

³ Department of Geology, Islamic Azad University of North Tehran Branch, Iran.

Abstract

Generally the most important factor in the structural evolution of Alborz is thrust and reverse faulting that often has an east-west trend, parallel to the mountain chain. Mosha fault, one of the main faults, in this study covers the area between longitudes 51˚, 30´ to 51˚, 45´ including central-western part of Mosha fault. The stress evolution on the available faults in northeast of Tehran city was studied by means of inversion of 120 striated fault planes and related striations. Finally, two different movement systems were identified.  One of them generated dextral reverse faulting and the other one which is younger created sinistral reverse faulting. The dextral system, known to resulted from the movement of the Arabian plate toward the north, is determined to be Miocene and probably older. The sinistral system originates from structural transition of AlborzMountain (progressive deformation in Alborz). Obtained result shows that the movement vector on the thrust Mosha is the consequence of the combination of sinistral and reverse faulting. The ages of stress changes were determined by using the cross cutting

Keywords

• Mosha Fault
• inversion method
• Progressive Deformation
• Reverse Fault
• Strike Slip Fault