Structure of Ravand fault and its role on extensional pull-apart basin in Oromieh-Dokhtar volcanic belt

The NNW-SSE striking Ravand strike-slip fault (a segment of Qom-Zefreh fault) extended from southeast of Qom to northwest of Kashan. The Ravand fault is segmented to three parts of the N162 striking southern segment، the N-S striking central segment and the N150 trending northern segment. Structural study on this fault clear that، dextral strike-slip mechanism is the most recent movement of the Ravand fault and it was already as a releasing step over to right in Qom–zefreh fault path that was forming a pull-apart basin because of dextral shear tectonic in this region during convergence between Arabian plate and Iran. This is the reason why the Eocene volcanic deposits exposed in lozenge shaped area surrounded by faults in western part of the Ravand fault.