Features of early-stage tectonic deformation of the Xileng Formation-complex in the Zhangbaling area, Anhui Province

Abstract：The complexity of the early-stage tectonic deformation in the Xileng Formation-complex in the Zhangbaling area, Anhui Province is mainly manifested by folds and ductile shear deformation closely related to folds. There are at least three stages of tectonic deformation in strata, of which F1 is NW-trending ductile shear folds at an outcrop scale, F2 is SSW-plunging flexural folds, and F3 is nearly E-W-trending broad folds. F1 and F2 combine to constrain the gross framework of the distrilution of the Xileng Group-complex . Microfabrics, especially the magnetic fabric features of rocks, prove that multi-stage tectonic deformation took place in the area. Two stages are most conspicuous, i.e. the early-stage horizontal shear and ensuing lateral extrusion. The paper focuses on the geometric features of the above-mentioned fold deformation and also analyzes its kinematics and dynamics.