The Tan-Lu fault zone moved as a sinistral strike-slip fault during post-collisional stage of the Dabie Orogen, but its movement timing is still ambiguous. A series of granitic and mafic dikes developed in the Tan-Lu fault zone on the eastern terminal of Dabie Orogen, which formation were close to strike-slip movement of the Fault zone. Therefore, development of dikes can offer timing evidences for the strike-slip movement of the Tan-Lu fault zone. In this work, six samples were collected from mylonites and dikes in the Tan-Lu fault zone for zircon LA-ICP-MS dating. Two groups of ages, Neoproterozoic and Indosinian, and no Early Cretaceous age data were obtained from two granitic mylonites, indicating that intense deformation restrained formation of zircon rim. A mafic dike, emplacing along fault plane of the fault zone, and a ductile deformed monzogranite formed at ca. 128 Ma, which suggests that strike-slip movement of the Tan-Lu fault zone was still??under??way at that time. Another mafic dike, crossing obliquely with the mylonite foliation, formed at about 127 Ma. A K-feldspar granite just with NE-striking cleavages emplaced at ca. 126 Ma. Considering these age data and previous works synthetically, the Tan-Lu fault zone should move before 128 Ma during the Early Cretaceous and then transfer to normal fault movement.
Wang Yongsheng Du Hui Hu Zhaoqi Tian Ziqiang Bai Qiao. Timing of sinistral strike-slip movement of the Tan-Lu fault zone on the eastern terminal of the Dabie Orogen: Evidences from LA-ICP-MS U-Pb zircon dating[J]. Chinese Journal of Geology, 2019, 54(3): 818-836.