Structural Evidences of Continental Transpression in the Birk Area(SE Iran)

Some structural evidences of continental transpression are studied and compared with experimental modeling results in the Birk area. These evidences are: fold axes have a double plunging en-echelon pattern. Fold axes mean orientations and fracture cleavages strike form angles less than 45 degrees with the boundary faults. Strike-slip faults have an en-echelon and domainal pattern. Synthetic P Shears are more abundant than synthetic R shears. Flat tension vein (and normal faults) planes lie at a high-angle with respect to folds axes and this condition proposes some amounts of hinge-parallel extensions. Inclined dextral layer-parallel detachment faults and related structures such as asymmetric dextrally verging minor folds, traspressional and trastensional faults and large-scale half flower structures are other structural features of dextral transpression. It is believed that partitioning of dextral component of wrench-dominated continental transpression is due to reactivation of N-S striking basement faults in late Neogene.