从青藏高原南北两个磨拉石剖面的对比看青藏高原的隆升过程

Uplift Processes of the Qinghai-Tibet Plateau Interpreted from the Comparison of Yecheng Section and Siwalik Group

通过对昆仑山北麓的叶城剖面的实测及其与喜马拉雅山南麓的SuraiKhola剖面的对比分析表明 ,约 10MaBP以来 ,青藏高原以持续性隆升为主 ,划分高原整体隆升阶段的有效时间尺度下限是 1Ma ,高原隆升过程可划分为三大阶段 :10 0～ 6 0MaBP ,高原整体缓慢隆升 ;6 0～ 2 5MaBP为过渡性隆升阶段 ;2 \^5MaBP以来高原整体快速隆升。高原整体隆升高度可能于 4 6MaBP超过海拔 2 0 0 0m ,2 5MaBP超过海拔 30 0 0m。

Comparative analysis of the Yecheng seciton at north piedmont of the Kunlun Mountain, and the Surai Khola section at south piedmont of the Himalayan Mountain, suggests that the Qinghai-Tibet plateau is dominated by continuous uplift over the past 10 million years, and the effective time scale for dividing the entire plateau uplift processes is 1 Ma or more. The entire process of the entire plateau can be divided into three stages based on sediment facies and deposit ratio, namely slow uplift stages between 10^0～6^0 Ma BP; transitional uplift stage between 6^0～2^5 Ma BP (including medium-velocity uplift of the south part of the plateau and low-velocity uplift of the north part of the plateau during 6^0～4^6 Ma BP; medium-velocity uplift of the south part of the plateau and high-velocity uplift of the north partole the plateau during 3^5～2^5 Ma BP), and the high-velocity uplift stage after 2^5 Ma BP. The uplift elevation of the entire plateau exceeded {2 000} m above sea level maybe by 4^6 Ma BP and exceeded{3 000} m above sea level by 2^5 Ma BP.