• RSS
  • E-mail Alert
  • 收藏主页

古地理学报 ›› 2014, Vol. 16 ›› Issue (1): 30-40. doi: 10.7605/gdlxb.2014.01.030

• “黔北务正道地区铝土矿”专题 • 上一篇    下一篇

黔北务正道地区铝土矿层特征及其反映的早二叠世古气候*

余文超1, 杜远生1, 周 琦2, 金中国3, 汪小妹4, 崔 滔4   

  1. 1 中国地质大学(武汉)生物地质与环境地质国家重点实验室,湖北武汉 430074
    2 贵州省地质矿产勘查开发局,贵州贵阳 550004
    3 贵州省有色金属和核工业地质勘查局,贵州贵阳 550005
    4 中国地质大学(武汉)资源学院,湖北武汉 430074
  • 收稿日期:2013-04-19 修回日期:2013-06-17 出版日期:2014-02-01 发布日期:2014-02-01
  • 通讯作者: 杜远生,男,1958年生,中国地质大学(武汉)教授、博士生导师,主要从事沉积地质学研究。E-mail:duyuansheng126@126.com。
  • 作者简介:余文超,男,1988年生,中国地质大学(武汉)博士研究生,主要研究方向为沉积地质学。E-mail:evilchaos@sina.com。
  • 基金资助:
    贵州省地勘基金 “贵州务正道地区铝土矿基础地质与成矿背景” 项目资助

Palaeoclimate of the Early Permian: Evidence from characteristicsof bauxite beds in Wuchuan-Zheng′an-Daozhen area, northern Guizhou Province

Yu Wenchao1, Du Yuansheng1, Zhou Qi2, Jin Zhongguo3, Wang Xiaomei4, Cui Tao4   

  1. 1 State Key Laboratory of Biogeology and Environmental Geology,China University of Geosciences(Wuhan),Wuhan 430074,Hubei
    2 Bureau of Geology and Mineral Exploration and Development of Guizhou Province,Guiyang 550004,Guizhou
    3 Non-ferrous Metals and Nuclear Industry Geological Exploration Bureau of Guizhou Province,Guiyang 550005,Guizhou
    4 Faculty of Earth Resource,China University of Geosciences(Wuhan),Wuhan 430074,Hubei
  • Received:2013-04-19 Revised:2013-06-17 Online:2014-02-01 Published:2014-02-01
  • Contact: Du Yuansheng,born in 1958,is a professor and Ph.D. supervisor of China University of Geosciences(Wuhan)and is mainly engaged in sedimentology. E-mail: duyuansheng126@126.com.
  • About author:Yu Wenchao,born in 1988,is a Ph.D. candidate of China University of Geosciences(Wuhan)and is mainly engaged in sedimentology.E-mail: evilchaos@sina.com.
       

RichHTML

PDF

摘要： 铝土矿的形成受到气候条件的严格限制。通过对黔北务川—正安—道真地区下二叠统铝土矿层钻孔岩心样品主量元素和黏土矿物的综合研究,探讨了铝土矿层形成时期黔北地区的古气候环境以及淋滤作用对矿层的改造。从下至上,铝土矿层化学蚀变指数(CIA)由80左右上升至大于90,成分分异指数(ICV)由0.8下降至0.1。X射线衍射分析发现,研究区铝土矿层中的黏土矿物组分为高岭石、伊利石与绿泥石,其中高岭石在各个钻孔中广泛存在且在大部分层位中含量较高,平均含量为34.2％,并呈机械碎屑或基质形态产出且有进一步风化成为铝矿物的现象;伊利石主要以机械碎屑形式产出,平均含量为21.5％,赋存于矿层的黏土质部分,结晶度变化范围为0.22°～0.71°;绿泥石多为基质,部分层位中含量极高且伴随ICV值上升,平均含量为44.3％,为后期成岩过程中由高岭石转化而成。矿层内极高的CIA值与广泛存在的高岭石证明,铝土矿形成时为炎热潮湿的古气候。而矿层内部ICV值的波动可能与淋滤作用所引起的矿层内元素迁移活动有关。

关键词: 铝土矿, 地球化学, 黏土矿物, 古气候, 早二叠世, 黔北

Abstract: Bauxite,as a kind of climatically sensitive deposit,mainly formed during the pedogenesis under the tropical or subtropical climatic condition.The integrated information of major elements and clay minerals from drilling core samples of bauxite beds in Wuchuan-Zheng′an-Daozhen area,northern Guizhou Province,was measured to investigate the palaeoclimate environment during the formation process of bauxite. Chemical index of alteration(CIA)and index of compositional variability(ICV)of samples from bottom to top of the drilling core revealed that CIA increased from 80 to >90,while ICV decreased from 0.8 to 0.1.Both of them indicated the strong chemical weathering which changed composition of bauxite beds greatly. The clay mineral compositions of bauxite beds were dominated by kaolinite,illite and chlorite.Kaolinites,which appeard in debris or matrix,widely distributed in every drilling core and had a high content in most layers;illites mainly appeard in debris,occurring in clay layers of the deposit,with illite crystalline index varying in wide range;while chlorite matrix derived from kaolinite during later diagenesis.High CIA value and clay mineral composition in bauxite beds indicated moist and warm palaeoclimate environment in northern Guizhou Province during the Early Permian which related to palaeogeography position of this area.Change of ICV value in the bauxite beds was related to element migration during leaching process.

Key words: bauxite, geochemistry, clay mineral, palaeoclimate, Early Permian, northern Guizhou Province

中图分类号: