The Flexural Stress Field Of The Continental Lithosphere In Western China

Western China is characterized by complex topography and spectacular tectonic features. It is the most active tectonic area of the Eurasia. There is a large deformation of the lithosphere in response to the gigantic topographic loading in this area. Therefore the flexural stress covers a large percentage of the total stress field. The study of the flexural stress field of the continental lithoshpere in Western China will contribute a lot to the understanding of the tectonic evolution of continental lithosphere and the global plate tectonics.Based on the lithosphere rheology, we use a 3D method in space domain to calculate the flexural stress field of the continental lithoshpere in Western China. In this thesis, the vertical variation of the flexural stress field is presented. The relationship between the flexural stress field and the vertical and horizontal loading is also discussed in details respectively.The result shows that the flexural stress of the western China is about several hundred MPa. Tien Shan is under large compression with the compressional stress varies from 300 MPa to 600 MPa. The Tibetan Plateau is mainly under compression with the exception of the interior of the plateau which is under extension. Areas beneath the mountain belts are under compression while areas beneath basins and the foredeep of the Indian plate are under compression. The vertical loading plays a major role in the state of the flexural stress. Beneath the mountain belts, the compression decreases and changes to extension from the top of the elastic plate to the bottom. The change of the flexural stress beneath thebasin is vice versa.