投稿时间:2021-12-15
修订日期:2022-06-15
网络发布日期:2022-09-09
中文摘要:桂林郑钼钨多金属矿床位于江南钨矿带北部,其矿石矿物以富钼白钨矿为主。研究显示,该矿床富钼白钨矿中富集稀土元素。为探究其富集机制,文章对不同世代的富钼白钨矿进行原位LA-ICP-MS微量分析和面扫描分析。结果显示,富钼白钨矿的总稀土元素含量(∑REE)在28.59×10-6~4863.82×10-6之间,均值为789.21×10-6(n=122),从第一世代(Sch-Ⅰ)28.59×10-6~1059.18×10-6(平均值为203.19×10-6,n=55)→第二世代(Sch-Ⅱ)533.54×10-6~2536.51×10-6(平均值=928.79×10-6,n=30)→第三世代(Sch-Ⅲ)117.21×10-6~4863.82×10-6(平均值=1547.13×10-6;n=37)逐渐增高。从Sch-Ⅰ→Sch-Ⅱ→Sch-Ⅲ,轻重稀土元素比值(LREE/HREE)13.99~143.90(平均值=53.53)→22.38~70.08(平均值=33.74)→7.44~69.86(平均值=27.54)逐渐降低。桂林郑富钼白钨矿形成于高氧逸度、富F的岩浆热液系统,REE主要以Ca2++Mo6+=REE3++(1-x) Mo5++xNb5+(0≤x≤1)为主导方式进入富钼白钨矿中。成矿流体中Cl降低、F增高、氧逸度降低等是REE进入富钼白钨矿的有利条件。通过对江南钨矿带代表性矽卡岩型矿床综合对比分析显示,富钼白钨矿床相比贫钼白钨矿床具有更高的REE,说明桂林郑矿床富钼白钨矿在后续开采中具有稀土元素的综合利用前景。
Abstract:The Guilinzheng Mo-W deposit is located in the northern part of Jiangnan tungsten mineralization belt (JWB), and its ore minerals are mainly high-Mo-bearing scheelite. Research shows that rare earth elements are enriched in high-Mo scheelite, in order to explore its enrichment mechanism, in-situ LA-ICP-MS trace elements analysis and mapping of orderly-stage high-Mo scheelite grains were conducted in this study. The results show that the total rare earth elements concentrations (∑REE) of the three-stage high-Mo scheelite ranged from 28.59×10-6 to 4863.82×10-6, with average value of 789.21×10-6 (n=122), and the ∑REE gradually increased from 28.59×10-6~1059.18×10-6, (Sch-Ⅰ, Avg.=203.19×10-6, n=55), 533.54×10-6~2536.51×10-6 (Sch-Ⅱ, Avg.=928.79×10-6, n=30) to (117.21×10-6~4863.82×10-6 (Sch-Ⅲ, Avg.=1547.13×10-6, n=37). From Sch-Ⅰ to Sch-Ⅱ to Sch-Ⅲ, the LREE/HREE ratios decrease from 13.99~143.90 (Avg.=53.53), 22.38~70.08 (Avg.=33.74) to 7.44~69.86 (Avg.=27.54). In Guilinzheng deposit, the high-Mo scheelite was formed in F-rich magmatic hydrothermal system with high oxygen fugacity, the alternative mechanism of REE entered into high-Mo scheelite is dominantly of Ca2++Mo6+=REE3++(1-x) Mo5++xNb5+ (0≤x≤1). Decreasing Cl, increasing F concentrations and lowering f(O2) degree in ore-forming fluid evolution are favorable factors for high-Mo scheelite with enriching REE during its formation. After systematically comparative study from the JWB representative W- polymetallic deposits, it shows that the high-Mo scheelite have visible higher REE concentrations than those Mo-poor scheelite, REE resources in Guilinzheng the high-Mo scheelite ore has the prospect of comprehensive utilization in the future mining industry.
keywords:geochemistry high-Mo scheelite rare earth element LA-ICP-MS Guilinzheng skarn deposit Jiangnan tungsten mineralization belt
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基金项目:本文得到国家自然科学基金项目(编号:41972076、91962218)、科技部深地资源勘查开采专项(编号:2016YFC0600206)、安徽省自然资源科技项目(编号:2021-K-9、2020-K-11)和安徽省公益性地质工作项目(编号:2021-g-2-11)联合资助
引用文本:
任康达,张达玉,孟翔,张飞,王静,席晓晨,张泽伟,苏海博.2022.江南钨矿带桂林郑富钼白钨矿稀土元素的富集机制及其地质意义[J].矿床地质,41(4):859~877REN KangDa,ZHANG DaYu,MENG Xiang,ZHANG Fei,WANG Jing,XI XiaoChen,ZHANG ZeWei,and SU HaiBo.2022.Enrichment mechanism of rare earth elements (REE) of high-Mo scheelite in Guilinzheng deposit from Jiangnan tungsten mineralization belt and its geological significance[J].Mineral Deposits41(4):859~877
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