地学前缘 ›› 2024, Vol. 31 ›› Issue (1): 127-141.DOI: 10.13745/j.esf.sf.2023.10.11

• 华北克拉通演化及其效应 • 上一篇    下一篇

内蒙古大青山-盘羊山晚中生代-早新生代构造事件及其对华北北缘构造演化的启示

张进江1(), 郑剑磊1, 王海滨1, 郭磊2, 刘江3, 戚国伟4   

  1. 1.北京大学 地球与空间科学学院 造山带与地壳演化教育部重点实验室, 北京 100871
    2.中国地质科学院 地质研究所, 北京 100037
    3.中国地质调查局 西安地质调查中心, 陕西 西安 710119
    4.北京大学 深圳研究生院, 广东 深圳 518055
  • 收稿日期:2023-09-06 修回日期:2023-10-10 出版日期:2024-01-25 发布日期:2024-01-25
  • 作者简介:张进江(1964—),男,教授,博士生导师,主要从事构造地质学和构造演化研究。E-mail: zhjj@pku.edu.cn
  • 基金资助:
    科学技术部国家重点研发计划项目(2021YF0716000);中国石油天然气集团有限公司-北京大学基础研究项目

Late Mesozoic-Early Cenozoic tectonic events in Daqingshan and Panyangshan, Inner Mongolia, and its implication for the tectonic evolution of the northern margin of the North China Craton

ZHANG Jinjiang1(), ZHENG Jianlei1, WANG Haibin1, GUO Lei2, LIU Jiang3, QI Guowei4   

  1. 1. MOE Key Laboratory of Orogenic Belts and Crustal Evolution, School of Earth and Space Sciences, Peking University, Beijing 100871, China
    2. Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, China
    3. Xi’an Center of China Geological Survey, Xi’an 710119, China
    4. Peking University Shenzhen Graduate School, Shenzhen 518055, China
  • Received:2023-09-06 Revised:2023-10-10 Online:2024-01-25 Published:2024-01-25

摘要:

内蒙古大青山和盘羊山位于华北克拉通北缘,其复杂的地质构造对华北克拉通北部中—新生代构造演化具有重要的指示作用。大青山以北的盘羊山逆冲体系,形成于晚二叠世至早三叠世古亚洲洋的闭合,晚侏罗世可能受蒙古-鄂霍次克洋闭合的影响而重新活动。大青山地区发育4期中—新生代变形构造,从老至新依次是:SE-NW向伸展形成的呼和浩特变质核杂岩、NW向逆冲的大青山逆冲体系、以不变形花岗岩为核心的构造穹窿、大青山山前断裂及高角度正断层。发生于约142~132 Ma的SE-NW向伸展,形成于造山增厚地壳的重力垮塌,并形成呼和浩特变质核杂岩和相关的拆离体系。大青山逆冲体系形成于约130~120 Ma,代表造山过程中地壳荷载与板块汇聚的抗衡导致的构造反转,另一可能是古太平洋俯冲的远程效应。自约120 Ma以来,大青山处于一个构造-热松弛期,导致该区约120~90 Ma的冷却事件被广泛记录,并形成以不变形花岗岩(约114 Ma)为核心的穹窿构造;这些事件可能与华北克拉通的峰期破坏相关。大青山山前断裂和相关的高角度正断层开始于始新世,可能是印度-欧亚大陆碰撞和太平洋板块运动方向改变的远程效应所致。古亚洲洋和蒙古-鄂霍次克洋的闭合导致华北克拉通北缘地壳增厚,引发早白垩世造山晚期的垮塌和伸展,形成呼和浩特变质核杂岩。自120 Ma开始,大青山开始受华北克拉通破坏的影响,并形成后造山伸展。新生代,大青山受新特提斯和太平洋构造域的远程影响。

关键词: 中生代, 新生代, 逆冲, 变质核杂岩(MCC), 构造转换, 大青山, 华北克拉通北缘

Abstract:

The Daqingshan and Panyangshan in Inner Mongolia are located in the northern margin of the North China Craton (NCC), and their complex geological structures can provide a constraint on the Mesozoic-Cenozoic tectonic evolution of the northern NCC. To the north of Daqingshan is the Panyangshan thrust system, which formed originally in the Late Permian-Early Triassic by the closure of the Paleo-Asian Ocean and reactivated in the Late Jurassic possibly by the termination of the Mongolia-Okhotsk Ocean. Mesozoic-Cenozoic deformation of Daqingshan passed through four successive stages: the Hohhot metamorphic core complex (MCC) with SE-NW extension; the NW-ward Daqingshan thrust system; domes cored by undeformed granites; and the Daqingshan Front Fault and high-angle normal faults. The SE-NW extension took place from ca. 142 to 132 Ma and formed the Hohhot MCC and the related detachment system. This extension possibly resulted from gravitational collapse of the thickened crust caused by the Panyangshan thrusting. The Daqingshan thrust system formed between ca. 130-120 Ma, indicating a tectonic inversion from competition between plate convergence and crustal load as extension progressed. Another possible cause for the inversion is remote effect of Paleo-Pacific subduction. Since ca. 120 Ma Daqingshan has been in a tectonic-thermal relaxation regime represented by domes cored by undeformed granites of ca. 114 Ma and cooling events of ca. 120-90 Ma. These events might be related to the peak destruction of the NCC. The activation of the Daqingshan Front Fault and high-angle normal faults since the Eocene may be caused by remote effect of the India-Asia collision and change in the Pacific Plate movement. The closure of the Paleo-Asian and Mongolia-Okhotsk Oceans caused crustal thickening along the northern margin of the NCC, giving rise to the Early Cretaceous collapse, extension, and formation of the MCCs. The destruction of the NCC began to impact Daqingshan since 120 Ma, while in the Cenozoic the Neo-Tethys and Pacific realms remotely controlled the tectonic regime of Daqingshan.

Key words: Mesozoic, Cenozoic, thrust, metamorphic core complex (MCC), tectonic inversion, Daqingshan mountain, northern margin of the North China Craton

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