地质学报2016，Vol.90Issue(2)：219-230,12.
纳米比亚欢乐谷地区白岗岩型铀矿成矿物质来源分析
Ore-Forming Material Sources of the Leucogranite-type Uranium Deposit in the Gaudeanmus area,Namibia
摘要
Abstract
This paper presents a systematic study of major and trace elements, and Sr-Nd isotopes on leucogranites closely related to uranium mineralization in the Gaudeanmus area,Namibia.The results illustrate that uraniferous leucogranites are high in SiO2 (68.81% ~76.02%,averagely 73.11%)and K contents,with 0.96 ~ 1.07 of A/CNK (averaging 1.01 ),suggesting the sub-alkaline metaluminous to weakly peraluminous rocks.The rock is enriched in light rare earth elements,with LREE/HREE = 2.53~7.71,(La/Yb)N = 2.14~10.40,moderate Eu loss and high Rb/Sr ratios (2.03~5.50 with an average of 4.36);enriched in LILE,such as Rb,Th,U,K and Pb,and depleted in Ba,Nb,Ta and Sr.The initial 87 Sr/86 Sr ratios of the rock range from 0.73035~0.79345 with theεNd (t)values of -13.5~-17.4;theεNd (t)values of uraninites range from -14.8 to -16.5,and two-stage Nd model ages cluster between 2.43~2.56Ga.Detailed elemental and Sr-Nd isotopic geochemical characteristics infer that leucogranites were formed in the post-orogenic extensional environment;the U-rich pre-Damara basement dominantly contributed to the ore-forming material during the main mineralization epoch,whereas the additional uranium infilling at the hydrothermal superimposition-reformation epoch possibly came from the primary uranium minerals themselves.关键词
晶质铀矿/成矿物质来源/Sr-Nd 同位素示踪/白岗岩型铀矿/纳米比亚欢乐谷地区Key words
uraninite/ore-forming material sources/Sr-Nd isotopes/leucogranite-type uranium deposit/Gaudeanmus area,Namibia引用本文复制引用
陈金勇,范洪海,王生云,顾大钊,陈东欢..纳米比亚欢乐谷地区白岗岩型铀矿成矿物质来源分析[J].地质学报,2016,90(2):219-230,12.基金项目
本文为非洲中南部古老地块铀矿综合识别评价技术及应用研究项目的成果。 （）
