西藏札达盆地控盆断裂有限元数值模拟  

Finite element numerical simulation of the tectonic stress field of basin-control-ling faults in the Zanda basin, Tibet, China

作　　者：段岩[1] 孟宪刚[2] 邵兆刚[2] 朱大岗[2] 

机构地区：[1]中国地质大学,北京100083 [2]中国地质科学院地质力学研究所,北京100081

出　　处：《地质通报》2008年第10期1720-1727,共8页Geological Bulletin of China

基　　金：中国地质调查局国土资源调查项目(编号:1212010610108;1212010511902);国家自然科学基金项目(编号:40572134)资助

摘　　要：札达盆地是喜马拉雅构造带中的一个山间断陷盆地,其演化过程与盆地两侧的控盆构造密切相关。对控盆断裂的构造应力场进行模拟计算,将有助于进一步深化对本区构造控盆的认识。因此,在对盆地构造地质进行详细调查的基础上,结合本区的深部地质与地球物理资料,对札达盆地控盆断裂的构造应力场进行了模拟。计算结果表明,札达盆地的演化明显受盆地两侧边界断裂的控制,札达盆地是在整体南北向挤压应力的作用下,不同块体差异隆升作用的结果。其南侧的控盆断裂为北倾的正断层,北侧的控盆断裂为南倾的逆断层,二者共同组成了南降北升的翘板式断陷盆地运动过程,是喜马拉雅地块在陆内汇聚挤压构造环境中构造应力场调整的一种方式。The formation and evolution of the Zanda basin as an intermontane downfaulted basin in the Himalaya tectonic belt are closely related to the basin-controlling tectonic movement on both sides of the basin. The finite element numerical simulation of the tectonic stress field of basin-controlling faults will be helpful to further understanding the basin-controlling tectonic characteristics in the area. Therefore, based on a detailed survey of the tectonics, combined with the deep geological and geophysical data of the area, the tectonic stress field of the basin-controlling faults in the Zanda basin was simulated. The results show that the formation and evolution of the Zanda basin were obviously controlled by the boundary faults on both sides of the basin. The formation of the Zanda basin is the result of the differential uplift of different blocks under the N-S compressional stress. The basin-controlling faults on the south are north-dipping normal faults and those on the north are south-dipping thrust faults, both of which combine to generate a process of seesaw-type tectonic downfaulted basin movement （the south descended and the north ascended）. It is a way of adjusting the tectonic stress field of the Himalayan block in the whole synchronous convergent compressional enviromnent.

关 键 词：西藏札达 控盆断裂 构造应力场 有限元数值模拟 

分 类 号：P542.3[天文地球—构造地质学]