青藏高原隆升及伸展变形中的重力位能

青藏高原在南侧印度板块和北侧欧亚板块的双向挤压下整体抬升,边界挤压力所作的功增加了高原内部重力位能.但高位能态的物质会不断向重力势能最小的平衡态转移,并产生流变变形.由于受南北边界的挤压力约束,高原内部的高位能驱使喜马拉雅山和昆仑山之间的地体产生东西向伸展变形.利用三种不同方法对青藏高原重力位能进行计算,结果表明,一定流变学条件下,青藏高原目前所具有的重力位能可以产生各地体中观测到的地表构造变形速率.

THE ROLE OF GRAVITATIONAL POTENTIAL ENERGY IN RAISING AND SPREADING OF QINGHAI-XIZANG PLATEAU

In Qinghai Xizang plateau, the extrinsic forces due to the collision between lndia plate and Eurasia plate act on the continental lithosphere and cause a raise in vast area. The boundary forces add the gravitation potential energy of the plateau by two sided pressing. Such a high potential energy tends to drive the plateau to spread continuously from high point to lower point and strongly affectits deformation. Because of the constraints of south north compression, the release of high potential energy of the inner plateau mainly drives the plateau to produce east west extension between Himalayan and Kunlun Mountains. Using three different methods, we estimated the distribution of gravitational potential energy of Qinghai Xizang Plateau. The result shows that the gravitational potential energy of Qinghai Xizang Plateau is sufficient to produce the wide variety of rates and styles of observed deformation given available constraints on rheology. [