青藏高原东部晚新生代重大构造事件与挤出造山构造体系
作者:
作者单位:

作者简介:

通讯作者:

中图分类号:

基金项目:

国家自然科学基金(41472178)和中国地质调查局地质调查项目(1212011120167,12120114002211)联合资助。


Late Cenozoic tectonic events in east Tibetan Plateau and extrusion-related orogenic system
Author:
Affiliation:

Fund Project:

  • 摘要
  • |
  • 图/表
  • |
  • 访问统计
  • |
  • 参考文献
  • |
  • 相似文献
  • |
  • 引证文献
  • |
  • 资源附件
  • |
  • 文章评论
    摘要:

    文章系统梳理了青藏高原东部地区晚新生代重大构造事件的沉积记录、岩浆记录和构造变形响应,重新厘定了青藏运动或横断事件的起始时限,建立了青藏高原东部晚新生代构造演化序列与挤出造山构造体系。研究认为,发生在上新世之前的青藏运动是青藏高原东部最重要的构造作用阶段,起始于距今12~8 Ma,并持续到上新世早期,持续时间达6~8 Ma。在这个构造运动阶段,青藏高原东部地块(川滇地块、川青地块、西秦岭构造带和陇中地块等)有序地向东挤出,受到鲜水河、东昆仑、海原等WNW-ESE向大型断裂左旋走滑运动调节,构造挤出同时伴随地块内部逆冲褶皱变形,导致地壳增厚和高原东缘山脉快速崛起;构造挤出也超越了现今东缘地貌边界,向东扩展导致扬子地块盖层滑脱褶皱,形成龙泉山、大凉山等褶皱构造带。上新世出现的砾石层(东缘前陆地带的大邑砾石层、临夏盆地的积石砾石层、兰州盆地的五泉砾石层等)标志了青藏高原东部差异性构造地貌的形成。上新世晚期至早更新世时期(3.6~1.0 Ma)对应一个构造松弛阶段,青藏高原东部整体进入冰冻时期,沿其东缘发育一系列受正断层控制的南北向伸展断陷盆地,如安宁河谷地、元谋盆地、盐源盆地、滇西北盆地群等,其中加积了以昔格达组为代表的稳定河湖相沉积。发生在早、中更新世之交(距今1.0~0.6 Ma)的昆-黄运动或元谋事件使青藏高原东部地块进一步向东挤出、东缘地壳逆冲增厚和年轻山系加速隆升。晚更新世以来的构造运动称为共和运动或最新构造变动阶段,起始于距今约120 ka,青藏高原东缘构造变形系统出现重大分化,南段川滇菱形地块发生绕喜玛拉雅东构造结的顺时针旋转运动,形成川滇双弧形旋扭构造体系;而中段川青地块的挤出伴随东缘龙门山断裂带的右旋走滑运动和秦岭山系的向东挤出。在这个最新构造变动阶段,青藏高原东部下地壳通道流可能是重要的深部构造驱动因素。

    Abstract:

    This paper revised the chronology of major late Cenozoic tectonic events in east Tibetan Plateau, mostly based on records of stratigraphy in the basins and magmatism and deformation along active fault zones, with the purpose of establishing an evolution history of extrusion-related orogenic system. It is shown that the most important event, as previously named the Qingzang movement, was initiated at 12-8 Ma and lasted to early Pliocene, with a duration of 6-8 Ma. The crustal fragments in east Tibet, such as the Chuan-Dian, Chuan-Qing, Longzhong blocks, were orderly extruded eastward accommodated by large-scale sinistral strike-slip faults like the Xianshuihe, East Kunlun and Haiyuan faults. This eastward extrusion was concomitant with thrusting, which resulted in fast uplift of the ranges along its eastern edges, and went beyond this margin through decollement, generating folds of the cover rocks like the Longquanshan, Daliangshan in the Yangze craton. The deposition of late Pliocene conglomeratic layer, namely the Dayi conglomerates along the eastern foreland zone, the Jishi conglomerates and the Wuquan conglomerates at the northeast corner of Tibet, marked the emergence of contrast geomorphology in this region. Late Pliocene to early Pleistocene (3.6-1Ma) corresponds to a period of tectonically quiescence or relaxation, during which a set of N-S trending rift basins, such as Yuanmu, Yanyuan, and Anninghe, were developed along the eastern margin, and accumulated a series of fluviao-lacustrine facies deposits in these basins. This relaxation stage was followed in Early-Middle Pleistocene (1.0-0.6 Ma) by an important compressional event named the Kun-Huang or Yuanmu event, which caused further uplift of east Tibet. Active faulting pattern in east Tibet has been changed greatly since the late Pleistocene (about 120 Ka), featured along its southwest part by clockwise rotation around the east Himalaya syntax of two sinistral strike-slip fault zones, and along its central north part by a counter clockwise rotation accommodated by dextral strike-slip motion in the Longmenshan fault zone and eastward push of the Qinling range. The lower crustal flow could be a major driven mechanism for the deformation of this most recent stage.

    参考文献
    相似文献
    引证文献
引用本文

张岳桥,李海龙. 青藏高原东部晚新生代重大构造事件与挤出造山构造体系[J]. 中国地质, 2016, 43(6): 1829-1852.
ZHANG Yue-qiao, LI Hai-long. Late Cenozoic tectonic events in east Tibetan Plateau and extrusion-related orogenic system[J]. Geology in China, 2016, 43(6): 1829-1852(in Chinese with English abstract).

复制
分享
文章指标
  • 点击次数:
  • 下载次数:
  • HTML阅读次数:
  • 引用次数:
历史
  • 收稿日期:2016-07-08
  • 最后修改日期:2016-09-30
  • 录用日期:
  • 在线发布日期: 2016-12-21
  • 出版日期:
亮点文章推荐
古人云:工欲善其事,必先利其器。我国新一轮战略找矿行动已全面启动。用什么方法、什么手段实现增储上产是面临的突出问题。本刊登载了几篇基于新技术、新方法实现找矿突破的实例,供大家参阅,助力新一轮战略找矿目标的实现。
基于随机森林算法的找矿预测——以冈底斯成矿带西段斑岩—浅成低温热液型铜多金属矿为例. 欧阳渊等,2023, 50(2):303-330.
基于重磁资料在山东齐河—禹城探获矽卡岩型富铁矿:对超深覆盖区找矿的启示. 王润生等,2023, 50(2):331-346.
自然伽马曲线重构波阻抗反演在勘探含铀有利成矿砂体中的尝试. 梁建刚等,2023, 50(2):347-358.
宽频大地电磁法寻找“界面型”隐伏金矿床:以黔西南戈塘地区深部找矿为例. 张伟等,2023, 50(2):359-375.
页岩气基础地质调查钻井技术研究进展及展望. 赵洪波等,2023, 50(2):376-394.
关闭