南海北部陆缘有限变形分析——以西沙海槽为例  

Analysis of the Finity Deformation in the Continental Splitting in the Northern Margin of the South China Sea——A Case Study of Xisha Trough

作　　者：张健[1] 宋海斌[2] 李家彪[3] 

机构地区：[1]中国科学院研究生院计算地球动力学重点实验室,北京100049 [2]中国科学院地质与地球物理研究所,北京100029 [3]国家海洋局海底科学重点实验室,杭州300012

出　　处：《中国科学院研究生院学报》2005年第3期341-345,共5页Journal of the Graduate School of the Chinese Academy of Sciences

基　　金：国家自然科学基金项目 (4 0 4740 3 1;40 1740 2 7);国家重点基础研究发展规划项目 (G2 0 0 0 0 4670 4)资助

摘　　要：依据有限变形理论 ,计算了不同壳幔密度结构条件下西沙海槽构造应力场及其有限变形 .结果表明 :现今海槽中部处于隆升状态 ,最大隆升速率可达 7× 1 0 -3 cm a ,上、下地壳分界面上有限变形水平应变分量exx在海槽中部为压性 ,南北两侧为张性 ;垂向应变分量ezz在中部为张性 ,两侧为压性 .The geologic deformation generally is predigested as a tiny distortion problem in studies.However,some actual geologic progress,i.e.,the rise and subsidence of Xisha Trough in margin crust splitting of the South China Sea do not accord with the condition of tiny distortion, whereas,the geologic progress belongs to the finite deformation problem.According to the theory of finite distortion,this paper calculated the field of tectonic stress and deformation components of Xisha Trough.The result shows that the moving direction of tectonic deformation depends on the size of structure resistance.The resistance is the smallest in the vertical direction in central Xisha. The largest vertical deformation appears here.Presently,there is a rising move with a velocity of 7×10 -3cm/a in the center of Xisha Trough.The strain component e xx of finite distortion is compression at the center of Xisha Trough,but is tension at south and north sides.On the other hand,the strain component e zz of finite distortion is tension at the center of Xisha Trough,but is compression at south and north sides.

关 键 词：大陆边缘张裂 西沙海槽 有限变形 

分 类 号：P541[天文地球—构造地质学]