## 1 Introduction
Tectonic slices of the highly deformed domain of thrust  
Figure 1: (**a**) Map of the investigated area plotted on shaded relief map of SRTM digital elevation model; red star represents the location of the 18 April 2021, M\({}_{\rm W}\) 5.8 mainshock and the black one indicates the 21 May 2021, M\({}_{\rm W}\) 5.0 aftershock [4]; black pentagons indicate historical earthquakes [8]; white rectangles mark the footprints of Sentinel-1 images used in this work; red lines are the active faults in the area [9; 10]. Abbreviations are; ZFF-Zagros Foredeep Fault, HZF-High Zagros Fault, MFF-Mountain Front Fault and MZRF-Main Zagros Reverse Fault. Dark blue line show boundaries of cratons and tectonic belts as deformation front [11]. (**b**) Zoom on the investigated area, with the geological map [12]. The ZFF fault extends through sedimentary rocks and cuts simple folding of Bakhtiari, Lahbari, Aghajari formations (B, L and A labels in figure, respectively) [13]; Arrow shows the relative velocity of Arabia with respect to Eurasia in mm/year [14]; green circles indicate aftershocks up to 15 July 2021. (**c**) A simplified cross-section through northeast to southwest of (**a**) [15; 16; 17]. (**d**) Geological profile of SS’ in (**b**) and enlarged (**c**) section [10; 13]. zone, including the Arabian margin, remains of island arcs, fragments of Cretaceous ophiolites and accretionary prisms, developed above a basal detachment in the latest Neoproterozoic-Lower Cambrian Hormuz evaporates or lateral equivalent [17; 20; 22]. In the Zagros belt, the deformation and tectonic process that reactivated the Late Cretaceous-Paleogene abduction belt is characterized by thin- and thick-skinned tectonics [17]. Tectonic deformation of the Zagros foreland basin was closely related to the propagation of faults from the Arabia-Eurasia suture zone to the southwestern side [22]. The Simply Folded Belt, limited by the HZF and the MFF, is characterized by many elongated anticlines. The low folded zone, located to the southwest of the MFF (Figure 1b), is characterized by a series of elongate folds of Miocene strata [23]. Multi-detachment folds with subordinate thrusting characterize the deformation of the sedimentary cover of the Arabian margin [24]. According to the progressive limb rotation model of fold kinematics, these formations are growth strata which accumulated during folding. As a result of folding, N- and NW-trending basement faults accommodated shortening [10]. Multiplicity of decollement levels promotes a partly decoupled deformations and limits the size of most faults in the area [19; 24]. The Dezful embayment changes the obliquity of Arabian plate convergence, controls the slip rate of faults, and contributes to the formation of the ZFTB [10]. The study area is bounded by the Zagros Forcedeep Fault (ZFF) and the Borazjan fault. Inverse ZFF is generally northwest-southeast with a slope to the northeast [1]. It separates the foredeep Zagros belt (north and northeast) from the Quaternary alluvium of the Persian Gulf coastal plain (south and southwest) and in the form of overthrust fault branches, has cut the folds in the region [1]. The strike-slip segment of the Kazerun Fault displaced the High Zagros Fault southward [10]. The ZFF has been extended as a dextral fault along the active Kazerun-Borazjan fault for 105 km and is composed of various hidden fault segments that partition the compressional structures within this range. This fault, like the MFF with a predominant thrust regime and the HZF with a combination of thrust and strike-slip regimes [10], is a deep fault that, after cutting the sedimentary cover of the upper crust, extends to the lowest parts of the crust and reaches the shear zone to Moho. As a result of the thrust Borazjan fault activation, the fold axis has curved, elongated, and dislocated across the Zagros belt as dextral [25] (Figure 1). Under NE dip low-angle basal thrusts, Arabian basement rocks are deformed by large crustal thrusts that actually merge at depth and correspond to the uppermost crystalline basement [24].