Evidences for Development of a Pull-Apart Basin in the Rostam-Abad Region, Gilan Province

Razavi Pash, R; Ghassemi, M.R; Safari, H

doi:10.22071/gsj.2015.41999

Evidences for Development of a Pull-Apart Basin in the Rostam-Abad Region, Gilan Province

Document Type : Original Research Paper

Authors

R Razavi Pash ¹

M.R Ghassemi ²

H Safari ³

¹ Ph.D. Student, Faculty of Science, Department of Geology, Shiraz University, Shiraz, Iran

² Associate Professor, Research Institute for Earth Sciences, Geological Survey of Iran, Tehran, Iran

³ Assistant Professor, Department of Geology, Faculty of Science, Golestan University, Gorgan, Iran

10.22071/gsj.2015.41999

Abstract

The study area is located in western Alborz range, and is part of the Lahijan sinistral strike-slip fault system. This area is observed as a depressed basin on the digital elevation model. This research uses field studies, remote sensing techniques and statistical methods to investigate and analyze geometry and kinematics of the faults in the Rostam-Abad area, and benefits structural and geomorphic evidences to introduce a pull-apart basin in the area. Our analysis indicates that the Rostam-Abad area is located in the overlap zone of two sinistral strike-slip fault segments of the Lahijan fault zone with a left-step array. Presence of frequent normal faults, extensional fractures, rhombic pattern of the depression, extensive alluvial deposits, and intrusion of igneous dykes in young sandstones within the Rostam-Abad depression also verify a local extensional tectonic regime in this region.

Keywords

Rostam-Abad

Western Alborz

Pull-apart basin

Sinistral strike-slip faults