Acad Sinica, Inst High Energy Phys, Beijing 100080, Peoples R China
; Chinese Acad Geol Sci, Inst Mineral Resources, Beijing 100037, Peoples R China
; China Univ Geosci, Beijing 100083, Peoples R China
Fission track geological chronology is an effective method of study on tectonic movement of fault zone. Apatite fission track (AFT) dating analyses of 9-apatite and 4-zircon samples collected from Lhasa to Langkazi, similar to70-km-long in SN provide an understanding of the age and the uplifting of both sides of the Yarlung Zangbo Thrust Zone (YZTZ) in this work. The AFT ages range from similar to37 to 14 Ma, indicating the time of major tectono-thermal events, i.e. the continent-continent collision along the YZTZ. Based on the relationship between the AFT ages and the sample elevations, there were two tectonic active periods: similar to37-20 Ma and 20-14 Ma. In the first period the tectonic event did not bring on differential uplifting. Rapid differential uplifting with rapid cooling, resulting from thrusting, took place in the second period. The vertical displacement was similar to1020 m and total similar to2.9 km of overburden has been removed from the present-day surface since cooling below similar to110degreesC began. The maximum cooling and denudation occurred at a rate of similar to7degreesC/Ma and degrees207 m/Ma respectively since similar to14 Ma. The zircon fission track analysis demonstrates that the temperature of tectono-thermal events did not exceed 310degreesC.