Abstract: The authors describe the geometry and deformation features of the Machaoying fault zone in the Huaxiong terrane, southern margin of North China Craton. The Machaoying fault underwent ductile and brittle deformation stages. Ductile deformation mainly occurs in the southern area of the fault zone with greenschist facies metamorphism. Movement sense of the overthrust indicated by S-C fabrics in the fault zone is toward south in the southern part and toward north in the northern part, respectively. This positive flower pattern indicates that the fault is a typical strikeslip fault with thrusting feature. The ductile deformation happened likely in the preYanshanian epoch. The brittle deformation mainly occurred in the nouthern part during continent-continent collision in the Yanshanian epoch. NE trending Kangshan-Qiliping and Hongzhuang-Taocun faults are subsidiary shear fractures of the Machaoying strikeslip fault. Combining with the previous studies the movement sense of the NE trending faults and their distribution patterns suggest that the Machaoying fault is a sinistral strikeslip fault. Based on the dynamics of geological setting the evolution of the fault zone in the area has been discussed.

Key words: Huaxiong terrane, Machaoying fault, strikeslip fault