AN ACTIVE FAULT ZONE IN THE WESTERN KOPEH DAGH (IRAN)

作者：Bretis Bernhard^*; Grasemann Bernhard; Conradi Florian

来源：Austrian Journal of Earth Sciences, 2012, 105(3): 95-107.

• tectonic geomorphology
• microstructure
• Kopeh Dagh
• Iran

Based on remote sensing studies, field work and microstructural investigations, we present new kinematic data and a structural model for the evolution of the Ashkhaneh/Takal-Kuh Fault (ASHF), an approximately 80 km long E-W trending fault in the S part of the Western KopehDagh (Iran). The ASHF system consists of an oblique thrust with a number of sinistral strike slip faults and tear faults with a marked displacement gradient. The tear faults clearly offset the thrust front, which consists of Cretaceous limestones. The offset and change of modern river courses suggest that the fault movement is still active. Several meters long and decimeter thick NE-oriented, monomineralic calcite vein systems are associated with the faults and suggest a strong fluid interaction during fault slip. Fluid pulses during brittle deformation are furthermore confirmed by microtectonic studies revealing alternating processes of frictional velocity weakening processes and velocity hardening deformation mechanisms by dissolution precipitation creep. %26lt;br%26gt;We therefore suggest that part of the Miocene to recent N-S shortening between the Iran and Eurasia has been accommodated by SSW-directed thrusting and sinistral strike-slip deformation along the ASHF.

• 出版日期2012