ABSTRACT: A Regional Structural Interpretation of the Zagros Mountain Belt in Northern Fars and High Zagros (SW Iran)

The structural style is controlled by the stratigraphic position of the decollement levels, that varies with depth for the different areas of the 300 km long transect. Within the sedimentary pile, the main decollement level is the Hormuz salt. Sometimes this decollement level as well as pre Hormuz sedimentary basins can be clearly observed on seismic lines. Paleozoic formations are therefore involved in the main structures. The second decollement and disharmonic level is the evaporitic Dashtak formation (Trias). The difference in the tectonic style between Northern Fars, in the southern part of the transect and High Zagros in the northern part of the transect is partly due to the lateral facies changes in the Triassic formations, from evaporite to dolomite. The shaly layers of the Kazhdumi (Cretaceous) and Pabdeh/Gurpi (late Cretaceous/Early Tertiary) as well as Gachsaran (Late Miocene) evaporitic layer can locally act as secondary decollement.