青藏高原西北缘地形抬升速率与地质年代的关系

Relationships between Topographic Uplifting Velocity and Geological Times for the Northwestern Edge of Qinghai-Tibet Plateau

基于数字高程模型数据和地质数据,首先对青藏高原西北缘西昆仑山脉的山脊线和山麓线进行地形剖面及其地面组成物质形成的地质年代分析,据此获取了从西北到东南的5座典型山峰:昆盖山、慕士塔格山、塔什库祖克山、慕士山和托库孜达坂山的相关数据;然后以公格尔山为例,探讨了山峰区域典型地形剖面线的获取方法;最后对5座山峰进行了典型地形剖面获取及其对应山体组成物质形成的地质年代分析,计算了每座山峰在不同地质年代的组成物质下的地形抬升速率。研究结果表明:西昆仑山脉从西北到东南的5座典型山峰,地形抬升速率在两端较大,中间部位则相对较小,在塔什库祖克山最小,呈近似"V"形;从西北部的昆盖山到东南部的托库孜达坂山,山体组成物质形成的地质年代数量为3-4-5-4-3,呈现先增多后减少的变化趋势,呈"Λ"形;因此,地形抬升速率与地质年代数量之间呈现负相关的关系。

Based on digital elevation model and geological data,this paper firstly analyzed the topographic profiles and the geological times of the composite materials of the ridge line and piedmont line of the northwestern edge of the Qinghai-Tibet Plateau-West Kunlun Mountains;Accordingly,the five typical peaks were selected from northwest to southeast： Mt.Kungai,Mt.Mushitage,Mt.Tashikuzuke,Mt.Mushi and Mt.Tuokuzidaban.Taking Mt.Konggur as an experiment area,the acquiring method of typical topographic profile was studied in the peak areas.Finally,the typical topographical profiles of the five typical peaks were acquired,the geological times of the composite materials of corresponding peaks were analyzed,and the topographic uplifting velocity under different geological times was computed for every typical peak.Research results show： from northwest to southeast,the topographical uplifting velocity is small in the middle part and big in two ends,and least in Mt.Tashikuzuke and presents near ＂V＂ shape;from northwestern Mt.Kungai to southeastern Mt.Tuokuzidaban,the numbers of the geological times of composite materials are 3-4-5-4-3,which present the tendency of increasing firstly and then decreasing and ＂Λ＂ shape.Thus,there exists a negative correlation between the topographical uplifting velocity and geological times.