Constraining the stepwise migration of the eastern Tibetan Plateau margin by apatite fission track thermochronology

作     者：LAI QingZhou DING Lin WANG HongWei YUE YaHui CAI FuLong 

作者机构：Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100085China 

出 版 物：《Science China Earth Sciences》 (中国科学（地球科学英文版）)

年 卷 期：2007年第50卷第2期

页      面：172-183页

核心收录：

学科分类：0709[理学-地质学] 070901[理学-矿物学、岩石学、矿床学] 07[理学] 

基　　金：Supported by Chinese Academy of Sciences (Grant No. KZCX3-SW-143) Chinese Ministry of Science and Technology (Grant No. 2002CB412602) the National Natural Science Foundation of China (Grant No. 40234049) 

主　　题：Tibetan Plateau fission track thermal history modeling margin migration constraining 

摘      要：Granites sampled from Garzê-Litang thrust, Longmen Shan thrust, Garzê and Litang strike-slip faults in the eastern Tibetan Plateau have been analyzed with apatite fission track thermochronological method in this study. The measured fission track apparent ages, combined with the simulated annealing mod- eling of the thermal history, have been used to reconstruct the thermal evolutionary histories of the samples and interpret the active history of the thrusts and faults in these areas. Thermal history mod- eling shows that earlier tectonic cooling occurred in the Garzê-Litang thrust in Miocene (~20―16 Ma) whereas the later cooling occurred mainly in the Longmen Shan thrust since ~5 Ma. Our study sug- gests that the margin of eastern Tibetan Plateau was extended by stages: through strike-slip faults deformations and related thrusts, the upper crust formed the Garzê-Litang margin in the Miocene epoch and then moved to the Longmen Shan margin since ~5 Ma. During this process, the deformations of different phases in the eastern Tibetan Plateau were absorbed by the thrusts within them and conse- quently the tectonic events of long-distance slip and extrusion up to hundreds of kilometers have not been found.