地学前缘 ›› 2012, Vol. 19 ›› Issue (5): 225-233.

• 论文 • 上一篇    下一篇

准噶尔盆地南缘新生代沉积物碎屑锆石记录的天山隆升剥蚀过程

陈熠,方小敏,宋春晖,孟庆泉   

  1. 1. 中国科学院 青藏高原研究所, 大陆碰撞与高原隆升实验室, 北京 100101
    2. 兰州大学 地质科学与矿产资源学院, 西部环境教育部重点实验室, 甘肃 兰州 730000
  • 收稿日期:2012-01-20 修回日期:2012-06-02 出版日期:2012-09-10 发布日期:2012-09-10
  • 作者简介:陈熠（1988—），男，硕士研究生，构造地质学专业。E-mail：chyhongfeng@163.com
  • 基金资助:

    国家发改委油气专项和国家重点基础研究发展计划“973”项目（2011CB403000）；国家基金委创新研究群体科学基金项目（41021001）

The uplift and erosion of the Tianshan Mountains recorded by detrital zircon geochronology from the Cenozoic sediments in the southern Junggar Basin.

  1. 1. Key Laboratory of Continental Collision and Plateau Uplift, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China
    2. School of Earth Sciences and Mineral Resources, Lanzhou University, Key Laboratory of Western China’s Environmental Systems (MOE), Lanzhou 730000, China
  • Received:2012-01-20 Revised:2012-06-02 Online:2012-09-10 Published:2012-09-10

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摘要：

通过对准噶尔盆地南缘有精确古地磁年代控制的金沟河剖面新生代沉积物中7个砂岩样品碎屑锆石的UPb LAICPMS测年分析，确定安集海河组（28~23.3 Ma）和沙湾组（23.3~17.5 Ma）的砂岩样品碎屑锆石年龄主要集中在261~328 Ma（P-C），塔西河组（17.5~13.2 Ma）样品的年龄主要集中在234~311 Ma（T-C）和369~403 Ma（D-S），独山子组（13.2~6.0 Ma）和西域组（6.0~1 Ma）样品的年龄主要集中在264~333 Ma。经与流域内岩石地层的分布相对比，揭示至少在晚渐新世开始中天山已经隆升并剥蚀为盆地提供物源，从约中新世早期开始北天山的南缘开始隆升，加入物源供给区，从约中新世中晚期开始北天山开始明显隆升，并逐步阻碍了中天山的物源供给，成为物源的主要供给区。天山的这种逐步向北的隆升剥蚀过程，反映了印度欧亚板块碰撞的远程效应。

关键词: 准噶尔盆地, 天山, 碎屑锆石, 新生代, 物源, 隆升剥蚀

Abstract:

Detrital zircon grains were collected from seven layers of sandstones along the paleomagnetically welldated Cenozoic sequence in the Jingou River section on the northern piedmont of the Tianshan Mountains. LAICPMS UPb dating of the zircon grains yields a large range of age spectrum with the Anjihaihe Fm. (paleomagnetic ages 2823.3 Ma) and Shawan Fm. (23.317.5 Ma) having peak zircon ages of 261328 Ma (PC), the Taxihe Fm. (17.513.2 Ma) 234311 Ma (TC) and 369403 Ma (DS), and the Dushanzi Fm. (13.26.0 Ma) and Xiyu Fm. (6.01 Ma) 264333 Ma. As compared with the lithostratigraphic distribution in the drainage reaches, it reveals that the central Tianshan Mountains began to uplift as a provenance and subjected to erosion in as late as  late Oligocene, then these processes extended to the southern margin of the northern Tianshan around the early Miocene, and finally to the whole northern Tianshan Mountains. Around mid and late Miocene the northern Tianshan Mountains began to prominently uplift and gradually impeded the supply of sediments from  central Tianshan Mountains and finally became the major provenance. The northward progressive uplift and erosion of  Tianshan reflect the distant responses of the collision  between India  and Eurasia Plates.

Key words: Junggar Basin, Tianshan Mountains, detrital zircon, Cenozoic, provenance, uplift and erosion

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