The Tongcheng segment of Tanlu fault zone is located in the northeastern margin of the Dabie orogenic belt. Firstly, the macrostructural characteristics, mineral composition and zircon U-Pb chronology of two sets of gneiss at both ends of the shear zone are studied, and it is determined that the gneiss was the product of high-pressure metamorphism during Indosinian orogeny. Later, due to the sinistral ductile strike-slip activity superposition of Tanlu fault zone, NE-SW-trending mylonite-supermylonite zone was formed on the basis of gneiss in the original EW-trending orogenic belt. According to the deformation behavior of the main minerals in mylonite, it is estimated that the deformation temperature of the shear zone was about 450 ℃～530 ℃, which can reach 550 ℃ locally, which indicates that it has undergone high greenschist facies to low amphibolite facies. The results of finite strain measurement and strain strength calculation show that the minerals have undergone intense elongation deformation during ductile shear activity, and the deformation degree is the strongest in the middle of the shear zone and weakens slowly toward both sides. Kinematic vorticity measurements of mylonite by various methods show that the Tongcheng section of Tanlu fault zone is a thin tape of general shear zone dominated by simple shear.
Li Zhenwei Song Chuanzhong Li Jiahao Wang Yangyang Yuan Fang Wang Wei Chen Shouwen. Analysis of structural deformation in Tongcheng section of Tanlu fault zone[J]. Chinese Journal of Geology, 2019, 54(4): 1185-1209.