The Sarvabad Fault, a new segment along the Main Recent Fault (MRF), Zagros, western Iran

Abstract

The Main Recent Fault (MRF) is an active right-lateral strike-slip fault system along the Zagros collision in SW Iran. The geometric and kinematic characteristics of this fault are known along most of its segments. However, a part of this fault exposed between the Morvarid and Marivan segments is ambiguous. This paper introduces the Sarvabad fault segment with a length of about 50 km along the NW parts of the MRF. For this purpose, digital elevation model (DEM), detailed structural field data, and the geological mapping were used. These were complemented by morphometric analyses and the analytical hierarchy process (AHP). The results revealed that the attitude of the Sarvabad Fault is N52°W/80°NE (22°S slip rake angle) in the central and SE parts. In the NW parts of the study area, the strike of this fault changes to N70°W and dips 80°E (25°S slip rake angle). Measuring the morphometric indices and the analysis of their results with the AHP model indicated that the NW parts of the study area have a higher relative tectonic activity than the SE parts. In addition, the parts of the study area along the Sarvabad Fault show a high relative tectonic activity. The most notable reasons for active tectonics along the Sarvabad Fault are V-shaped valleys, fault-line valleys, and asymmetric basins.