Role of the Kazerun Fault Zone in the formation and deformation of the Zagros Fold‐Thrust Belt, Iran

Abstract

The Kazerun Fault is a N‐S trending fault zone, which obliquely truncates the NW‐SE trending Zagros Fold‐Thrust Belt. This active fault zone is an ancient structural lineament which has controlled the structure, sedimentation, and subsidence of the central part of the Zagros since the Early Cambrian and has had an influence on the formation of the hydrocarbon system of the belt. The Kazerun Fault limited the distribution of the Cambrian Hormuz salt (the major decollement horizon that separates the Precambrian basement from the thick sedimentary cover) to the west. Its later reactivation with other N‐S trending fault zones (e.g., the Izeh Fault Zone) during the Cretaceous resulted in major sedimentary thickness and facies variations along the belt. This study presents a new interpretation for the evolution of the Kazerun Fault Zone based on field evidence and a review of various published and unpublished data. It is argued that at the surface, the fault zone is delineated by four north‐south trending segments and that marked differences occur in the distribution of deformation on either side of the fault segments in the Late Tertiary. During this time these segments acted as transfer faults (lateral ramps) linking different segments of the Zagros deformation fronts.