So far there is a dispute on active modes and time of the Tan-Lu fault zone. This paper used 40Ar-39Ar geochronology to study the samples of muscovite, biotite, plagioclase or K-feldspar from the mylonites along the sinistral Tan-Lu ductile shear zone on eastern terminal of the Dabie Mountains. It was discovered that the Tan-Lu fault zone acted as a sinistral strike-slip one before 139 Ma, then became an extensional one. Our work revealed that the transition time might be 128~139 Ma ago. In the course of extension, the Tan-Lu ductile shear zone experienced slowly rift and cooling, which caused the minerals with less closure temperature recorded small ages. The 40Ar-39Ar ages of 110 Ma of the biotite and 97～92 Ma of the plagioclase indicated that the extension activity of the Tan-Lu fault zone continued to about 90 Ma.
Wang Yongsheng,Zhu Guang,Song Chuanzhong et al. 40Ar-39Ar GEOCHRONOLOGY RECORDS OF TRANSITION FROM STRIKE-SLIP TO EXTENSION IN THE TAN-LU FAULT ZONE ON EASTERN TERMINAL OF THE DABIE MOUNTAINS[J]. Chinese Journal of Geology, 2006, (2): 242-255.