NUMERICAL MODELING OF BASEMENT INHERITANCEAND SALT LAYER EFFECTS ON THE STRUCTURALEVOLUTION OF THE FARS ARC

Structural evolution of fold-and-thrust belts is affected by the presence of pre-existing zones ofweakness. This study uses a two-dimensional finite difference model with a visco-elasto-plastic/brittlerheology to investigate the structural evolution of the Fars Arc in the southeast Zagros belt, which hasresulted from a tectonic inversion, from the Permian intracratonic rifting to the Oligocene continentalcollision. The influence of the weak Hormuz salt layer at the base of the stratigraphic column and thegeometry of inherited faults are examined. In a tectonic extensional environment, half-grabens are theprimary and initial structures of extensional basins, formed along pre-existing normal faults and arethe locations of sediment subsidence concurrent with rifting. Our modeling results indicate that thegeometry and positioning of inherited faults and an existing salt layer at the base control thewavelength of folding during the collision phase. Also, pre-existing normal faults affect the Hormuzsalt layer, leading to faulting in the sedimentary cover. The interaction of weak zones with each otherlead to the involvement of the basement in deformation and the development of thin-skinned andthick-skinned deformation to varying degrees.

کلیدواژه ها:

Numerical Modeling ، Fold-And-Thrust Belt ، Zagros ، Tectonic Inversion ، Salt Layer ، Basement Fault