Uplift of southeastern Tibet and Sanjiang area during Cenozoic era ——Thermal inversion analysis from fission track data
Jin Weijun1, He Dengfa2, Lei Zhenyu3, Kong Xiangru1
1. Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029;
2. China University of Geosciences, Beijing 100083;
3. Research Institute of Petroleum Exploration and Development,PetroChina,Beijing 100083
We analysis the regional tectonics uplift quantitatively and the thermal history inversion of in the southeast Tibet Plateau and Sanjiang area by 8 apatite and zircon fission track samples.The research indicates that the southeast Tibet Plateau experiences two tectonics uplift stages.The tectonics uplift is at 50 Ma and 6～5 Ma separately.Its characteristic is of slow uplift in the early stage,and fast uplift rate at 0.5 mm/a during the later stage.The tectonics uplift in Chuxiong Basin of Sanjiang area is affected by the middle fault and basement uplifts.The vertical movements are shown opposite trend in the Eastern and Western sub depression separately during 120～60 Ma.The cohesive uplift is occurred about 50 Ma affected by the Tibet Plateau uplift.The NE trend of ages and lengths distribution of samples in the area is resulted by the lateral extension on the condition of SE free boundary after Indian and Gangdese blocks collision.