地学前缘 ›› 2020, Vol. 27 ›› Issue (4): 282-293.DOI: 10.13745/j.esf.sf.2020.4.42

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皖南前南华纪浅变质岩系的沉积地质特征及其构造古地理意义

韩瑶,张传恒,李利阳,蒋先强,刘子荟   

  1. 1. 山东省地质环境监测总站, 山东 济南 250014
    2. 中国地质大学(北京), 北京 100083
    3. 武警黄金部队第四支队, 辽宁 辽阳 111000
  • 收稿日期:2019-08-20 修回日期:2020-04-08 出版日期:2020-07-25 发布日期:2020-07-25
  • 通讯作者: 张传恒(1962—),男,博士,教授,博士生导师。
  • 作者简介:韩瑶(1987—),女,博士研究生,工程师,古生物学与地层学专业,主要从事前寒武纪沉积地层和大地构造学研究。E-mail:summerflower_11@163.com
  • 基金资助:

    中国地质调查局项目“全国陆域及海区地质图件更新与共享”(DD20190370)、“全国地质构造区划与区域地质调查综合集成”(DD20160345)和“主要地质单元区域地质调查片区总结与服务产品开发”(1212011120115)

Sedimentary characteristics of the pre-Nanhua epi-metamorphic rock series in southern Anhui Province and the tectono-paleogeographic implications

HAN Yao,ZHANG Chuanheng,LI Liyang,JIANG Xianqiang,LIU Zihui   

  1. 1. Shandong Geological Environmental Monitoring Station, Jinan 250014, China
    2. China University of Geosciences(Beijing), Beijing 100083, China
    3. Fourth Detachment of Gold Headquarters of China Armed Police Force, Liaoyang 111000, China
  • Received:2019-08-20 Revised:2020-04-08 Online:2020-07-25 Published:2020-07-25

摘要:

皖南地区前南华纪浅变质岩系是江南造山带东段的重要组成部分。根据对本区前南华纪浅变质地层——环沙组和牛屋组所进行的沉积地质学研究,可识别出浊积岩相和深海—半深海相沉积,两者均属活动类型沉积建造。进一步的沉积相序研究表明,环沙组沉积环境总体反映出浅—深—浅—深的沉积变化,牛屋组沉积环境总体反映出由深变浅的沉积变化。对发育于环沙组和牛屋组上段的小型斜层理进行测量,经水平校正后两者古流向都指向北,证明其物源都来自南方。沉积岩骨架颗粒统计结果表明,环沙组物源构造属性为岩浆弧,牛屋组上段物源构造属性为再旋回造山带。结合侵入牛屋组下段的花岗岩地球化学特征研究,推测环沙组沉积于弧后盆地,牛屋组下段沉积于边缘海盆地,牛屋组上段沉积于周缘前陆盆地。在总结前人研究成果的基础上,探讨了江南造山带东段本区相应时段的大地构造演化格局。

关键词: 环沙组, 牛屋组, 沉积地质特征, 江南造山带, 构造古地理

Abstract:

The pre-Nanhua epi-metamorphic stratum in southern Anhui Province is an important part of the Jiangnan oregenic belt. Based on the sedimentary study of the Huansha and Niuwu formations, we can identify turbidite and deep sea-bathyal facies that both belong to the active type of sedimentary formation. Our research revealed that the sedimentary environment of the Huansha Formation reflects a shallow-deep sequence, while the Niuwu Formation features an upward-shallowing sequence. The sedimentary diffusion of the Huansha and upper Niuwu formations is northward directed, suggesting the provenances for the two formations must be from the south. Ternary plots of the sandstone point-count data showed that the Huansha and upper Niuwu formations were plotted in the magmatic-arc and recycled orogen fields, respectively. Combined with the geochemical research on granite intrusion in the Niuwu Formation, we conclude that the proto-basin of the Huansha Formation is back-arc basin, whereas the lower and upper Niuwu formations are marginal sea and peripheral foreland basins, respectively.

Key words: Huansha Formation, Niuwu Formation, sedimentary geology, Jiangnan orogen belt, tectono-paleogeography

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