【作者】 彭杨伟；

【导师】 张铭杰； 高军平；

【作者基本信息】 兰州大学 ， 矿物学、岩石学、矿床学， 2006， 硕士

【摘要】 青藏高原是全球独特的地域单元,它的隆升是新生代地质史上的重大的事件,其演化发展对全球气候变化有着巨大的影响。而青藏高原北部构造变形研究是认识印欧亚板块碰撞的远程效应、高原隆升过程的关键。 酒泉盆地和肃北盆地的古地磁研究成果为在该区应用碎屑颗粒热年代学方法提供了基础。本文试图在此基础上,通过青藏高原北部的酒泉盆地、肃北盆地裂变径迹的分析,探索青藏高原隆升的过程和机制。本文采集了酒泉-肃北盆地的火烧沟、瓷窑口剖面和铁匠沟剖面的23个新生代碎屑岩样品,进行了磷灰石样品分离和裂变径迹年龄的测定。分析结果表明:酒泉盆地源区在54.3Ma有一次快速蚀顶作用,33.8Ma-37Ma源区有一次构造抬升事件,在13-19Ma,酒泉盆地经历一次构造抬升冷却事件;肃北盆地源区分别在29.2Ma、26.7Ma、12.6Ma、8.7-10Ma构造抬升,在29.3Ma、8.4Ma、7.5-8.4Ma、5.3Ma、1.9Ma经历了构造冷却事件。以上构造事件显示印度板块碰撞变形应力在54.3-40Ma前传递到青藏高原北部边缘,此后又发生多次构造变形,其中青藏高原北部地区约8Ma显著隆升,周缘山区约5-2Ma强烈隆升。本文研究结果表明青藏高原的隆升是长周期夷平和短周期隆升的多阶段过程。更多还原

【Abstract】 The Tibetan Plateau is the world’s highest and youngest plateau, as an important event in Cenozoic, The uplift and formation of this Plateau affects on global and Asian climate and environment. The north margin of The Tibetan Plateau is the key to know how the Plateau to be formed in response to the plate collision between India and Asia.The study of magnetostratigraphy in Jiuquan and Subei basins gives me a basis to use the method of detrital grain thermochronology .The paper tries to use the apatite fission track ages of Jiuquan and Subei basins to test the models about the uplift of The Tibetan Plateau . The 23 samples were collected in Huoshaogou Section .Ciyaokou Section and Tiejianggou Section .Then, Apatite were Separated from the samples and their ages were tested .The Apatite Fission track ages show: a tectonic movement went through in the resorce area of Jiuquan basins from 33.8 Ma to 37Ma , Jiuquan basin undergo a tectonic movement from 13 to 19Ma;four tectonic movements went through in the resorce area of Subei basins during 29.2 Ma> 26.7 Ma、 12.6 Ma、 8.7-10 Ma ,a series of tectonic movements went through in Subei basin during 29.3 Ma> 8.4 Ma、 7.5-8.4 Ma、 5.3 Ma、 1.9 Ma . The study shows: about 54.3-40Ma, the north margin of Tibet have the record of the collision between India and Asia, a series of tectonic movements followed. The result of study shows that the uplift of Tibet is a process of unitary, multiple phases and unequal speed movement.更多还原