摘要
冷源铷矿是桂东北地区目前发现的规模最大的伟晶岩型铷矿床,产于越城岭岩体西侧加里东期花岗岩体内部的韧性剪切带内。赋矿伟晶岩脉从中心到边缘出现明显岩相分带,依次对称发育浅肉红色硅化钾长石伟晶岩→紫色萤石化钾长石伟晶岩→绿色绢云母化钾长石伟晶岩→白色钾长石伟晶岩。伟晶岩的主要造岩矿物为钾长石、石英和绢云母,在地球化学特征上以高硅[w(SiO2)>63.36%]、高铝[w(Al2O3)>14.36%]和富碱[w(K2O+Na2O)>11.50%]为特征,归属于碱性过铝质花岗岩类。伟晶岩中的稀有金属成矿元素主要为Rb,典型样品含量介于1883×10^-6~2355×10^-6,平均含量(2117×10^-6)达到铷矿工业品位2倍。伟晶岩中Rb元素含量与K元素含量正相关(r=0.9),指示Rb主要赋存于富钾矿物中(钾长石和绢云母)。在与冷源邻近的同禾、瓜里等伟晶岩脉密集区,伟晶岩中Rb元素含量大多都超过了圈定铷矿的边界品位,甚至部分伟晶岩脉中Rb含量达到了铷矿的工业品位,指示在桂东北越城岭西侧一带均有继续寻找伟晶岩型铷矿的良好找矿潜力。
The Lengyuan rubidium deposit is the largest pegmatite-type rubidium deposit discovered within the ductile shear zone at the western part of the Yuechengling granite body of Caledonian age in Northeast Guangxi.The Rb-bearing pegmatite shows typical lithoface zoning from the center to the edge,indicating for the red silicified potassium feldspar-pegmatite belt→the purple fluorite-pegmatite belt→the green sericitization feldspar-pegmatite belt→the white potassium feldspar-pegmatite belt.The main petrogenic minerals are potassium feldspar,quartz,and sericite.It is characterized by high silicon(SiO2>63.36%),high aluminum(Al2O3>14.36%),and alkali-rich[(K2O+Na2O)>11.50%]in the geochemical feature.The main rare-metal metallogenic element in pegmatite is rubidium(1883×10^-6-2355×10^-6),with the average of 2117×10^-6 up to two times of industrial grade.Rubidium is mainly distriubted in K-rich minerals(K-feldspar and sericite),and the content of rubidium increases synchronously with the content of potassium(the correlation coefficient r=0.9).Geological investigation indicates that there is a good potential to explore the pegmatite-type rubidium deposit in the west of Yuechengling of Northeast Guangxi,especially in Tonghe and Guali adjecent to Lengyuan for the Rb content of pegmatite veins mostly exceeds the boundary grade of the rubidium orebody in the two areas.
作者
王新宇
王酉臣
张润泽
王莉
杨金豹
冯梦
王建辉
蒋松林
付伟
WANG Xinyu;WANG Youchen;ZHANG Runze;WANG Li;YANG Jinbao;FENG Meng;WANG Jianhui;JIANG Songlin;FU Wei(College of Earth Sciences,Guilin University of Technology,Guilin 541006,Guangxi,China;Guangxi Bureau of Geology&Mineral Prospecting&Exploitation,Nanning 530023,Guangxi,China;Regional Geological Survey Research Institute of Guangxi,Guilin 541003,Guangxi,China)
出处
《矿产与地质》
2020年第3期439-445,456,共8页
Mineral Resources and Geology
基金
广西自然科学基金重点项目(2019JJD150009)
广西壮族自治区地质矿产勘查开发局部门预算前期工作经费项目(桂地矿综研〔2018〕20号)
广西找矿突破战略行动地质矿产勘查研究项目
广西科技基地和人才专项(桂科AD17129052)共同资助。
关键词
冷源铷矿
伟晶岩
成矿地质特征
桂东北
Lengyuan rubidium deposit
pegmatite
metallogenic and geological characteristics
Northeast Guangxi
