新生代青藏高原三维古地形再造

印度板块与欧亚板块的碰撞,引发了青藏高原的快速隆升、高原及邻区的气候环境、地形地势巨变,这一过程为同期形成的海洋沉积盆地、周缘前陆盆地和高原内部盆地所记录。高原隆升剥蚀区与前述三种类型的汇水盆地基本上处于一个相对封闭和半封闭体系,因而,可以根据质量平衡的原则,将汇水盆地内的沉积物按照物源方向和一定的分配方案回剥至隆升剥蚀区,重建任一时间段内剥蚀区的地形地势。通过对比不同时间段的古地形地势演变,可以比较精确和全面地刻划高原的隆升过程、隆升和剥蚀速率、隆升后所达到的海拔高度,进而探讨隆升与气候的关系,探索青藏高原在大陆碰撞体制下是增生扩大还是缩小

THREE DIMENSION PALEOTOPOGRAPHIC RECONSTRUCTION IN CENOZOIC TIBET PLATEAU

The collision of the Indian subcontinent with Eurasia was responsible for the rapid uplift, great changes of climate, environment, and topography in the Tibet plateau and nearby areas. This process was recorded by the basins developed simultaneously in marine, peripheral foreland basins and inner basins in plateau. They are in a relative closed or semi closed system between the range of uplift and erosion in plateau and the accumulation basin noticed as before. Hence, based on mass balance between erosion and sediment, the topography in the plateau in any time interval can be reconstructed, if sediments deposited in a catchment basin are distributed back to the erosion region in plateau as catchment surface of basin and distribution proportion. The uplift history, rates of uplift and denudation, altitude reaching after uplift can be revealed accurately by comparing paleotopography evolution in different time intervals, and the topics, such as the climate and environment influence caused by uplift, and plateau overgrown or shrink during collision, can be sought further .