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现代地质 ›› 2006, Vol. 20 ›› Issue (4): 573-578.

• 地层学 • 上一篇    下一篇

赣东北构造带中的“放射虫硅质岩”不是“茅口组硅质岩”

邓国辉1,龙军军2,贺和岭2   

  1. 1江西省地质调查研究院,江西 南昌330001;2赣西地质调查大队,江西 南昌330201
  • 收稿日期:2005-12-23 修回日期:2006-06-10 出版日期:2006-04-20 发布日期:2006-04-20
  • 作者简介:邓国辉,男,高级工程师,1963年出生,地质矿产勘查专业,主要从事区域地质调查研究工作。
  • 基金资助:

    国家基础地质调查项目(2000130000109)

The “Radiolarian Cherts” in the Structural-Ophiolitic Melange Belt, Northeastern Jiangxi,Is Not the “Siliceous Rock” of Maokou Formation

DENG Guo-hui1, LONG Jun-jun2, HE He-ling2   

  1. 1 Jiangxi Institute of Geological Survey, Nanchang,Jiangxi330001, China;
    2 Western Jiangxi Geological Surveying and Research Party, Nanchang, Jiangxi330201, China
  • Received:2005-12-23 Revised:2006-06-10 Online:2006-04-20 Published:2006-04-20

摘要:

赣东北构造带中的“放射虫硅质岩”主要分布于樟树墩—茅桥一带的赣东北蛇绿杂岩带之张村群中,与周边岩石地层呈断层接触关系,矿物成分和化学成分一致显示为泥质硅质岩,岩石遭受低级绿片岩相区域变质作用的改造,与泥质千枚岩、变质火山岩、蛇绿岩密切共生,含有“可疑的”晚古生代放射虫化石;茅口(孤峰)组硅质岩遍布于赣东北—皖南广大地区,整合于乐平组煤系地层之下、小江边组灰岩之上,具稳定的层位压盖关系,矿物成分和化学成分反映为纯硅质岩,岩石无变质重结晶现象,与碳质泥岩、灰岩互层,含大量的、珊瑚及腕足类化石,地层时代为二叠纪。因此,两者应分属不同的地层单位。

关键词: 张村群, 茅口(孤峰)组, 硅质岩, 构造混杂岩块, 赣东北

Abstract:

The “radiolarian cherts”within the Northeastern Jiangxi tectonic belt are mainly distributed in Zhangshudun-Maoqiao area, belonging to structuralophiolitic melange belt in Zhangcun Group, flanked by fault to the around lithostratigraphy. They are argillaceous siliceous rocks revealed by their mineral and chemical components. These rocks, associated with argillaceous phyllite, metavolcanite and ophiolite, contain “doubtful” Late Paleozoic radiolarian and are reconstructed by low greenschist-facies metamorphism. While the siliceous rock of Maokou (and/or Gufeng) Formation are widely developed in the Northeastern Jiangxi and South Anhui,they accord with the law of superposition (Smith Stratigraphy) and conformbly located under the coal measure strata of Leping Formation and on the limestone of Xiaojiangbian Formation. These rocks are “pure” siliceous rocks, belonging to the Permian Period. They contain aboundant fossils like the Brachiopod, Fusulinidea faunas and corals, without metamorphism and re-crystallization, associated with carbon-mudstone and limestone. Thus, the “radiolarian cherts” and the siliceous rock of Maokou Formation are diferent lithostratigraphic units.

Key words: Zhangcun Group, Maokou (and/or Gufeng) Formation, siliceous rock, structural-ophiolitic melange block, Northeastern Jiangxi

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