投稿时间：2021-10-12
修订日期：2022-01-30
网络发布日期：2022-05-06
中文摘要:湖子对山铀矿床位于粤北下庄铀矿田的中部，研究程度较低，对该矿床成矿时代和矿床成因缺乏必要的约束。文章通过LA-ICP-MS等技术手段，对湖子对山铀矿床开展了沥青铀矿U-Pb年代学及微量元素分析，结合矿石中黄铁矿LA-ICP-MS微量元素及硫同位素分析结果，对该矿床的成矿时代、成矿物质来源及矿床成因展开了讨论。研究表明，沥青铀矿中具有较高的普通铅含量，Tera-Wasserburg图解的投图结果表明其形成于（61.6±3.9）Ma（MSWD=1.4），与区域上部分铀矿床成矿时代一致，代表了华南地区一期重要的区域铀成矿事件。沥青铀矿中普通铅的207Pb/206Pb为0.624，表明成矿物质来源于积累了部分放射性成因铅的富铀源区，普通Pb可能以超显微非结构混入物的形式分布于沥青铀矿中。沥青铀矿LA-ICP-MS微量元素组成与黄铁矿显著不同，以富集W、Bi、Pb、Mo、Sb和亏损Cr、Co、Ni、Ti、As等元素为特征，表明成矿物质可能主要来源于花岗岩。黄铁矿微量元素具有低Co、Ni和富As的特征，表明其中低温热液成因，其Bi和Pb、Sb等元素含量较低，与沥青铀矿显著不同，结合镜下观察结果，认为黄铁矿形成于成矿前。该矿床黄铁矿硫同位素结果与诸广-下庄地区部分铀矿床结果一致，且接近于区域花岗岩硫同位素值，而区别于辉绿岩，表明该区部分铀矿床黄铁矿中的硫主要来源于区域花岗岩。
Abstract:The Huziduishan uranium deposit is located in the middle of the Xiazhuang uranium ore field in northern Guangdong, which has a low degree of research and lacks necessary constraints on the metallogenic age and genesis of the deposit. In this paper, U-Pb chronology and trace element analysis of pitchblende from the Huziduishan uranium deposit have been carried out by means of LA-ICP-MS and other technical methods. Combined with the results of LA-ICP-MS trace element and sulfur isotope analysis of pyrite in the ore, the ore-forming age, material source and the genesis of the deposit are discussed. The study shows that pitchblende has a high content of common lead, and the results of Tera-Wasserburg diagrams yield an age of（61.6±3.9）Ma(MSWD=1.4), which is congional uranium metallogenic event in South China. The 207Pb/206Pb of common lead in pitchblende is 0.624, indicating that the ore-forming materials are derived from uranium-rich sources that have accumulated part of radiogenic lead, and the common Pb may be distributed in pitchblende as ultramicroscopic unstructured mixtures. The trace element composition of pitchblende from LA-ICP-MS analysis is significantly different from that of pyrite, which is characterized by enrichment of W, Bi, Pb, Mo, Sb and depletion of Cr, Co, Ni, Ti and other elements, indicating that the ore-forming materials may be mainly derived from granites. The trace elements of pyrite have the characteristics of low Co, Ni and rich As, indicating its low temperature hydrothermal genesis and low contents of Bi, Pb, Sb and other elements, which are significantly different from pitchblende. Combined with the results of microscopic observation, it is considered that pyrite was formed before U mineralization. The sulfur isotope values of pyrite in this deposit are consistent with those of some uranium deposits in the Zhuguang and Xiazhuang uranium ore field, and are close to the sulfur isotope values of regional granite, but different from diabase, indicating that sulfur in pyrite in some uranium deposits in this area mainly comes from granite in the region. sistent with the uranium metallogenic age of some uranium deposits in the region, and represents an important re‐
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基金项目:中国核工业地质局《华南富大铀矿空间定位条件与远景预测研究》(编号:202138-10)资助
引用文本：
肖为,范洪海,庞雅庆,陈东欢,赖中信.2022.粤北湖子对山铀矿床年代学与矿物化学研究及其对铀成矿的启示[J].矿床地质,41(2):383~402XIAO Wei,FAN HongHai,PANG YaQing,CHEN DongHuan,LAI ZhongXin.2022.Geochronology and mineral chemistry study on Huziduishan uranium deposit in northern Guangdong Province and its implications for uranium mineralization[J].Mineral Deposits41(2):383~402
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