摘要
桂西平果、靖西、德保等铝土矿均分布于大新古溶蚀平原边缘地区.通过对矿床及围岩的稀土元素、非活动性元素、B、Be含量以及Sr/Ba、Th/U值等地球化学特征分析显示:(1)原生铝土矿REE配分模式与基底茅口灰岩、大新古陆泥灰岩及砂页岩REE配分模式,除总量略有差异外,其形态基本相似;(2)原生铝土矿、堆积铝土矿、茅口灰岩、古陆灰岩及砂页岩的Al2O3/TiO2,Al2O3/Zr,Al2O3/Hf,Al2O3/Nb和Al2O3/Ta值大多数比较接近;(3)原生铝土矿中w(B)=(79 57～109 14)×10-6,w(Be)=(0 71～13 75)×10-6,w(Sr)/w(Ba)=0 95～1 86,w(Th)/w(U)=2 37～3 23.桂西原生铝土矿物质来源主要为下伏的茅口灰岩、大新古陆灰岩及页岩,具有多来源的特征;原生铝土矿形成于海相环境,属于海相碎屑沉积矿床;堆积铝土矿同原生铝土矿相比,具有∑REE相对较低,∑Ce/∑Y相对较高,Ce呈正异常特点.
The region of Western Guangxi is an important base of bauxite deposits in China.Bauxite deposits in Pingguo, Jingxi, Debao distribute at the edge of Daxin diastrophic block. Systematical study on the geochemical characteristics of REE, non-active elements, B, Be, and the ratios of Sr/Ba and Th/U etc.shows as following:(1)The REE distribution patterns of the primary bauxites are basically parallel to those of Maokou limestone and the marlstone, the shale on Daxin diastrophic block, with little difference in total amounts. (2) Most of the ratios of Al_(2)O_(3)to TiO_(2), Zr, Hf, Nb and Ta are comparatively close, including Al_(2)O_(3)/TiO_(2), Al_(2)O_(3)/Zr, Al_(2)O_(3)/Hf, Al_(2)O_(3)/Nb and Al_(2)O_(3)/Ta of the primary bauxites, the pile-up bauxites, Maokou limestone and the marlstone, the shale on Daxin diastrophic block.(3)The values of B, Be,Sr/Ba and Th/U in the primary bauxites vary respectively between (79.57～109.14)×10^(-6),(0.71～13.75)×10^(-6), 0.95～1.86 and 2.37～3.23.On the basis of the above results,it is concluded that the ore-forming materials of the primary bauxites in Western Guangxi take on the property of multisource,mainly derived from the Maokou limestone and the marlstone, the shale on Daxin diastrophic block; the primary bauxites were formed in marine environment and belong to marine-oddment sedimentary deposits.Compared with the primary bauxites,the pile-up bauxites take on the properties of relatively low ∑REE, high ∑Ce/∑Y and positive anomaly of Ce element.
出处
《桂林工学院学报》
2004年第1期1-6,共6页
Journal of Guilin University of Technology
基金
国家教育部博士点基金资助项目(99053302)
关键词
铝土矿
稀土元素
非活动性元素
物质来源
桂西
REE
non-active elements
material derivation
bauxite deposit
Western Guangxi
