GNGTS 2013 - Atti del 32° Convegno Nazionale

Here we focused on the Zagros mountains which, longitudinally, is divided into two main geological domains: the North Zagros (hereinafter NZ) to the west and the Central Zagros (hereinafter CZ) to the east, separated by the NS-trending strike-slip Kazerun Fault System that cross-cuts the entire belt. NZ is considered as an high-taper wedge (ca. 2°) above a high- friction contact between the Phanerozoic cover and its Precambrian basement, whereas to the east, beneath CZ, the taper is lower (<1°) and pierced by diapirs of the infra-Cambrian Hormuz salt layer that lubricate the sole of the wedge (see Hessami et al. , 2006 and references therein). Taking into account a large geodetic and seismological dataset, we investigated the pattern of the present-day crustal tectonic stress and strain-rate fields characterizing the Zagros. In particular, we compiled a database of fault plane solutions (FPSs) by merging data from public catalogues and literature. Subsequently, we divided the mapped area into 1°×1° squares and applied a stress inversion analysis to estimate the directions of maximum horizontal compressional stress in each square. In addition, we analyzed new GPS data coming from recent continuously operating stations, which were rigorously integrated with published velocities in order to provide a more complete picture of the crustal deformation along the Zagros. As a final step, we compared the horizontal directions of compressive stress (from seismological and geological observations) with those of the minimum contractional geodetic strain-rate. Fig. 1 – Regional plate tectonic setting of the study region and surrounding areas. Abbreviations are as follows: BS, Black Sea; CS, Caspian Sea; NAF; North Anatolian fault; ESF, East Anatolian fault; HTJ, Hatay triple junction; MS, Mediterranean Sea; DSFS, Dead Sea fault system; MSZ, Makran subduction zone. Red box is showing the study area. 76 GNGTS 2013 S essione 1.1