A large-scale NNE-striking ductile shear belts are exposed inXiwei and Taohuayuan areasfrom the Feidongsegment of the Tan-Lu Fault zone. There is two phases of deformation in the ductile shear belt from Taohuayuan areas. Field structures and microstructures indicate sinistral ductile shear sense. Deformation behaviors of quartz and feldspar in mylonites from the shear belts demonstrate that deformation temperatures are 400~450 ℃ and ca. 500 ℃, respectively. Three mylonitized granite dikes in the ductile shear zone were dated by the zircon LA-ICP-MS method, and obtained weighted mean ages of (133.2±1.9) Ma,(131.3±2.0) Ma, and (130.3±2.0) Ma, respectively. Combined with previous research results, a sinistralstrike-slip of 128~124 Ma（middle Early Cretaceous）was identified. These results furtherimply that the strike-slip movement of the Tan-Lu Fault Zone took place in Late Jurassic and middle Early Cretaceous respectively since collision of the North and South China plates, and the fault zone was under the setting of extension in earlier and later Early Cretaceous. Extensional movement of the fault zone controlled the development of the Hefei basin to the west and magmatism along the fault zone, and the extensional movement lasted longer than the strike-slip movement. The Tan-Lu Fault Zone presented alternative the strike-slip and extensional movement from the late Jurassic to Early Cretaceous. The middle Early Cretaceous sinistralstrike-slip is a tectonic response to short-term adjustment of the Izanagi Plate motion directions and has a close relationship.
Han Yu, Niu Manlan, Zhu Guang, Wu Qi, Li Xiucai, Wang Ting. Geochronological Evidence for the Middle Early Cretaceous Strike-slip Movement from the Feidong Segment of the Tan-Lu Fault Zone[J]. Advance in Earth Science, 2015, 30(8): 922-939.