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现代地质 ›› 2013, Vol. 27 ›› Issue (2): 278-287.

• 构造与地层 • 上一篇    下一篇

六盘山地区早白垩世磁性地层年代及其构造意义

胡鸿飞1,2,3,戴霜2   

  1. 1中国地质大学 地质过程与矿产资源国家重点实验室,北京100083;
    2兰州大学 资源环境学院 西部环境教育部重点实验室,甘肃 兰州730000;
    3武警黄金第二支队,内蒙古 呼和浩特010010
  • 收稿日期:2012-07-20 修回日期:2012-12-30 出版日期:2013-04-01 发布日期:2013-04-22
  • 通讯作者: 戴霜,男,教授,博士生导师,1967年出生,自然地理专业,主要从事古地磁与环境磁学、构造地质领域的研究。
  • 作者简介:胡鸿飞,男,高级工程师,博士研究生,1969年出生,矿物学、岩石学、矿床学专业,主要从事矿产地质勘查与综合研究工作。Email:hhfdddd@sina.com。
  • 基金资助:

    国家重点基础研究发展计划项目(2009CB421008);国家自然科学基金项目(41272127);国土资源部地质大调查项目(1212011220492)。

Early Cretaceous Magnetostratigraphy of Liupanshan Area and Its Tectonic Implications

HU Hong-fei1,2,3,DAI Shuang2   

  1. 1State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Beijing100083;
    2Key Laboratory of Western China's Environmental Systems of Ministry of Education, College of Earth and Environmental  Science, Lanzhou University, Lanzhou,Gansu730000, China;
    3Gold Geological Party of CAPF, Hohhot, Inner Mongolia010010, China
  • Received:2012-07-20 Revised:2012-12-30 Online:2013-04-01 Published:2013-04-22

摘要:

研究六盘山白垩纪盆地演化对于认识中国大陆白垩纪及现今构造-环境格局形成具有重要意义。通过对六盘山地区火石寨剖面的沉积地层进行古地磁采样测量,初步获得六盘山群的磁性地层年代为100~130 Ma。综合古地磁测年结果、盆地沉积演化和构造事件分析,认为白垩纪六盘山盆地具拉张断陷性质,经历了早期拉张裂陷阶段(125.3 ~ 129.6 Ma)、中期扩张-稳定坳陷阶段(109.6 ~125.3 Ma)和晚期湖盆萎缩阶段(102.0~ 109.6 Ma)。盆地早期拉张裂陷和中期扩张坳陷阶段的时限与目前已确认的中国东部构造伸展转折的高峰期(110 ~ 140 Ma)相对应,是对中国东部岩石圈减薄作用和构造体制转变的响应。

关键词: 磁性地层年代, 早白垩世, 六盘山群, 构造意义

Abstract:

The research on the Cretaceous basin evolution of Liupanshan is crucial for understanding the formation of the Cretaceous and present China tectonic-environmental pattern. The paleomagnetic study of the Liupanshan Group in the Huoshizhai section in the central-northern Liupanshan basin yielded an age control on the Liupanshan Group at 110-130 Ma. Combined with the regional tectonic data the magnetostratigraphic results depicted that the Liupanshan basin was a rift-related depression basin and had undergone the early extension stage spanning in the period of 125.3-129.6 Ma, the middle expansion and stable depression stage during 109.6-125.3 Ma and the late extinction stage during 102.0-109.6 Ma. The age of the early extension stage is good to match with the time constraint obtained by the most studies of main duration of the tectonic extension in the east of China continent, indicating that this stage is the respondence to the lithospheric mantle detachment and geodynamic system transformation in the east of China continent.

Key words: magnetostratigraphy, Early Cretaceous, Liupanshan Group, tectonic implication

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