【作者】 李世杰；

【导师】 胡建中；

【作者基本信息】 中国地质大学（北京） ， 自然地理学， 2008， 硕士

【摘要】 西昆仑由于其特殊的构造位置使其成为地质学家和地理学家关注的热点地区。研究西昆仑造山带的隆升对于揭示青藏高原的隆升和塔里木盆地的形成演化具有重要意义。在研究山体抬升的众多方法中,磷灰石裂变径迹(FT)分析现已成为一种极为有效的工具。本文以裂变径迹理论为指导,分析了西昆仑不同地区新生代以来的裂变径迹年龄和裂变径迹长度,应用径迹年龄—地形高差法和外推法计算了西昆仑的隆升速率,并将西昆仑的隆升过程与邻区构造单元做了对比。磷灰石裂变径迹结果分析表明,西昆仑自渐新世以来经历了整体隆升过程;隆升速率表明西昆仑的隆升具有阶段性:15—5Ma期间极缓慢的隆升阶段;5—3Ma较快速隆升阶段;3Ma—现今加速隆升阶段。西昆仑内部不同地区隆升速率也不同,结果显示,西昆仑西段隆升速率大于中段。磷灰石裂变径迹研究表明,西昆仑新生代以来的隆升是一个长时期的在时间和空间上不均匀的演化过程,其隆升过程具有整体性、阶段性和差异性的特征。对比西昆仑与邻区构造单元新生代以来的隆升过程表明,西昆仑与阿尔金隆升存在相似的阶段性,但自晚新生代以来,二者隆升速率存在差距,西昆仑隆升速率大于阿尔金;作为青藏高原西北缘的西昆仑与处于青藏高原内部的东昆仑由于所处位置不同,二者的隆升过程也差异明显,西昆仑的速率要远高于东昆仑,并得到了裂变径迹年龄、河流阶地和GPS数据的支持。喜马拉雅造山带位于青藏高原的南缘,研究二者之间自新生代以来的隆升过程同样具有非常重要的意义。从对比结果来看,无论是裂变径迹年龄结果分析,还是大地水准测量和GPS数据都表明,喜马拉雅的隆升速率都要略高于同期的西昆仑的隆升速率,自上新世末以来(2Ma以来)差异尤其明显。从整个高原范围内来看,隆升速率从南向北有越来越慢的趋势,体现了印度板块与青藏高原碰撞的远程效应的时序性和差异性。更多还原

【Abstract】 West Kunlun Mt is always hot area to oversea and Chinese geologists and geographer , because of the special tectonic. Studying the uplift of West Kunlun has important significance to reveal the uplift of the Tibetan Plateau and The formation and evolution of Tarim Basin. Apatite fission track (FT) is a very effective tool of the most methods in the research of mountain body uplift.This paper is based on FT theory to analysis on fission track age and fission track length in different area of West Kunlun Mt since Cenozoic era and to calculate the uplift rate by the Fission Track Ages- Height Difference method and Extrapolation method and compare the uplift process to adjacent tectonic unit.The results of apatite fission track show that West Kunlun Mt experienced large uplifting since Oligocene. The uplift rate shows that the West Kunlun has different uplift stages: quite slow uplift stage (15-5Ma);faster uplift stage(5-3Ma); accelerated uplift stage(3Ma-now). Different areas have different uplift rate in the West Kunlun Mt. The results shows that the uplift rate in west section was larger than that in middle section. The uplift of West Kunlun Mt is a long heterogeneous process , which has the character of integrity, stage and difference in time and space since Cenozoic era by apatite fission track analysis.The comparison study of the uplift process between the West Kunlun Mt and adjacent tectonic unit shows that the West Kunlun Mt and the Altun Mountains have similar uplift process, but different uplift rate since late Cenozoic, uplift rate in the West Kunlun is higher than that in Altun. The West Kunlun, which situated on the northwest of Qinhai-Tibet Plateau, has different uplift process with the East Kunlun which situated internal Qinhai-Tibet platea and uplift rate in West Kunlun is much higher than that in East Kunlun because it’s supported by the evidence of FT, river terrace and GPS. Compare to the Himalaya located in the Qinghai-Tibet Plateau southern margin shows that the uplift rate of West Kunlun is slower than the contemporaneous that of Himalay especially since Late Pliocene (2Ma). View from the whole the range of Qinghai-Tibet Plateau , the uplift rate is more and more slower from south to north in general, which illustrates the time-order and difference of the far field effect of collision of the Indian and the Eurasian Plate.更多还原