The Neotectonics Movement And Its Effect On Environment And Resources In Menba Area, Tibet

This paper is based on the project of 1:250,000 geology survey of Menba sheet sponsored by China Geological Survey.The Neo-tectonics movement is quite active in Qinghai-Tibet plateau, which has strong effect on natural environment, resources distribution and geology disaster in Qinghai-Tibet Plateau and adjacent regions. It's an important way to probe into the mechanism of Qinghai-Tibet Plateau's uplift by study on unique features of lithosphere structure and tectonics-landforms, especially continuous serious deep thermal-tectonics in central plateau. To study the Neo-tectonics movement in Menba area, central plateau can not only provide reference to compared study in any other regions, limiting the era of Neo-tectonics Movement; but also discuss the effect of plateau uplifting on environment & resources. Moreover, it is important to probe into the mechanism of plateau's uplift.The Miocene Granite(about 790km2, average altitude about 6000m), a part of Nianqingtanggula Granite batholith, locates on two sides of the Dangxiong-Lhasa Fault in N-E direction, mostly are covered with present glaciers. The studys of dating, geochemistry and location on the granite show that it is related to Gulu fault in space and times. The granite may be related to the stretch of crust in E-W direction which maybe the result of deep thermal-uplift spreading, or uni-influence of deep thermal-uplift spreading and collision orogeny in central Qinghai-Tibet Plateau.The 3D geology-landforms model is made supported with RS and Gis techniques and the study on the step-like landforms in Menba area shows that, the mountain-top-surfaces with different altitude, which belong to one plantation surface formed in late Oligocene and dismembered since 18Ma, are...