Volume 18, Issue 50 (10-2005)
Abstract
Southern flank of the East– Central Alborz Mountain is consisting of several tectonic elements, which were introduced and analyzed, in this paper. This region is including a complex thrust system at north and a widespread foreland basin at south of Alborz– Central Iran border zone. Two significance curvatures at Alborz Mountain belt that have introduced here such as Neyshabur– Esfarayen– Shahrud Syntaxis and Damghan– Semnan– Qazvin Salient, had been created by change in trend of Alborz from NW– SE to NE–SW. According to this research, creative and activities of the fault systems in a sinistral displacement shear zone that had been elongated from south Semnan to north Gonbad–e Kavus was suggested as a cause to forming of above curvatures and thinning of Alborz width at north Bastam. Therefore, deformation in this region is a combination of compressional and left–lateral strike slip components that (Transpression) demonstrated by field evidences and focal mechanism solutions.
