Structural Geomerty of Moallem Kelayeh Inlier; an Evidence of Inversion Tectonic and Dextral Transpression in West Central Alborz Range

Document Type : Original Article

Authors

Department of Geology, Tarbiat Modares University

Abstract

 
Moallem-Kelayeh Inlier is located in western north Kandovan fault zone in west of central Alborz. Moallem Kelayeh Inlier is limited by Khashchal and Ovan faults in north and south, respectively. These faults with different dip direction caused lower Paleozoic rock units thrust over Cenozoic ones. Ovan fault is deeper than Khashchal fault and it formed as hanging wall back-thrust and caused Moallem Kelayeh Inlier be considered as a pop-up structure.
According to the Ovan Fault dip angle, development of its footwall thrusts and hanging wall back-thrust, hanging wall anticline and footwall syncline, exposure of the Barut Formation on its hanging wall and development of a pop-up structure, it is proposed that the  Ovan Fault was initialy normal fault reactived as a reverse fault. During inversion of the Ovan normal fault the Khashchal Fault has formed as back-thrust to the Ovan Fault.  The TF1 and Hanis thrust faults are also developed as footwall thrusts to the fault. In addition, the TF2 and TF4 thrust also formed as hanging wall thrusts to the fault. Final collision of Arabian plate-Central Iran at Miocene and ruling of dextral transpression regime caused development of strike slip faults in northern part of the study area that cut and displaced other faults. Thus, these faults are younger. Since these fault cut by Alam kuh and Nusha plutons, it is therefore deduced that these faults were not inactive during Pliocene.