Assessment the relationship between geometry and fault mechanism whit geomorphic index of active tectonic in west Alborz region

The movement of the earth's crust is one of the critical factors in the shaping of landscapes, so the effect of these movements on geomorphology and its related consequences can be identified by studying morphotectonics indicators. This study aimed to investigate the tectonic mobility, deformation pattern, and fault geometry of the Western Alborz zone in Iran.

 In this study, types of morphotectonics indicators such as sinuosity of the mountain front (Smf), river gradient (Sl), valley width to depth (Vf), asymmetry of waterways (Af), and hypsometric curves in thirty watersheds using topographic maps and satellite images were studied. The basins were classified into three categories: active, median, and inactive, and the status of the network of waterways and alluvial terraces, closely related to tectonics, were evaluated.

 The results showed that the tectonic regime prevailing in this area is a compression type. Thirteen watersheds are active, fourteen are moderately active, and the rest are inactive. This conclusion was reached by combining all the data. Some faults are inclined towards the south and others towards the north. The main faults are mainly reverse type in all sections.