关键词: 有限元模拟, 板块碰撞, 印度, 欧亚大陆, 构造变形, 三重非线性

Abstract:

Considering the triple-nonlinear character of continental tectonic deformation,the large de-formation in eastern Xizang area caused by continental collision between India and Eurasia is stud-ied by means of dynamic FEM. The results of numerical simulation show a sharp longitudinalcontractive defOrmation;most of principal strain axes have a tendency to rotate clockwise;but lat-eral displacement seems not remarkable. The maximum lateral displacement is between Hongheand Xianshuihe faults, the Sichuan-Yunnan rhombic block can move in SE direction.Honghe、xi-anshuihe、Kunlun and Altun fatilts rotate clockwise during collision. The slip along Honghe faultis sinistral in initial 8tage and dextral in lflter stage,but the slip along other three faults is sinistralall the time. Generally,the deformation caused by continental collision can be divided into sevenregions:a)the front edge region,Uthe horned region,c)the pulled region,d)the due front region,e)the oblique front region,f)the ahead flank region,and g)the flank region.

Key words: Finite element modeling, Plate collison, India, Eurasia, Tectonic deforma-tion, Triple-nonlinearity