Detrital Zircon Fission-Track Thermochronology of the Present-Day River Drainage System in the Mt. Kailas Area,Western Tibet:Implications for Multiple Cooling Stages of the Gangdese Magmatic Arc  

作　　者：Tianyi Shen Guocan Wang 

机构地区：[1]School of Earth Sciences、Center for Global Tectonics,State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences,Wuhan 430074,China

出　　处：《Journal of Earth Science》2020年第5期896-904,共9页地球科学学刊（英文版）

基　　金：the National Natural Science Foundation of China(Nos.41702208,41972223);the China Geological Survey(Nos.1212011121261,DD20179607,DD20160060,12120114042801)。

摘　　要：It is still controversial how the high elevation of the Tibetan Plateau established after the Indian-Asian collision during the Cenozoic. The timing of Gangdese magmatic arc exhumation and uplift history would provide useful message for this disputation. We present six zircon fission-track(ZFT) data from modern river sand in the western Tibet, around the Mt. Kailas, to decipher the long-term exhumation histories of the Gangdese magmatic arc. The data suggests that all the Gangdese magmatic arc rocks experienced rapid cooling during the Eocene(~46–35 Ma) and Oligocene(~31–26 Ma). The movement along the north-south trending extensional fault and dextral strike-slip Karakoram fault induced the adjacent rocks exhumed at the Middle Miocene(~15–16 Ma) and Late Miocene(~10–11 Ma), respectively. According to the minimum and central AFT ages for each sample, the fastest exhumation rate is about 0.4 km/Ma, with average long-term exhumation rates on the order of ~0.3 km/Ma since the Oligocene. This result supports the outward growth model for plateau forming, indicating the southern margin of the Gangdese magmatic arc attained high elevation after the Oligocene.

关 键 词：detrital zircon fission-track exhumation history Gangdese magmatic arc western Tibet 

分 类 号：P597.3[天文地球—地球化学]