桂北苗儿山矿田天门地区铀矿化及其矿物学特征研究  

Characteristics of Uranium Mineralization and Mineralogyin Tianmen Area of Miaoershan Ore Field, Northern Guangxi

作　　者：谭双[1,2,3] 刘晓东 吴昆明[2,3] 陈琪[2,3] 万建军 严杰[1] 雷勇亮 李鲲[2,3] 欧阳平宁 黄宏业 TAN Shuang;LIU Xiaodong;WU Kunming;CHEN Qi;WAN Jianjun;YAN Jie;LEI Yongliang;LI Kun;OUYANG Pingning;HUANG Hongye(State Key Laboratory of Nuclear Resources and Environment,East China University of Technology,Nanchang 330013,China;Changsha Uranium Geology Research Institute,CNNC,Changsha 410007,China;Hunan Engineering and Technology Research Center for Evaluation and Comprehensive Utilization of Associated Radioactive Mineral Resources,Changsha 410007,China)

机构地区：[1]东华理工大学核资源与环境国家重点实验室,江西南昌330013 [2]核工业二三〇研究所,湖南长沙410007 [3]湖南省伴生放射性矿产资源评价与综合利用工程技术研究中心,湖南长沙410007

出　　处：《原子能科学技术》2023年第7期1451-1464,共14页Atomic Energy Science and Technology

基　　金：国家自然科学基金(42262017);中核集团“青年英才”项目;中国核工业地质局地勘项目(202222);放射性地质与勘探技术国防重点学科实验室开放基金(RGET2205)。

摘　　要：天门地区位于苗儿山矿田中部,近年来通过地质勘查在该区加里东期花岗岩中连续发现铀矿体。本文对天门地区典型的黑色团块状铀矿石进行取样,通过光学显微镜、扫描电子显微镜、电子探针、综合矿物分析仪以及高分辨显微X射线荧光光谱仪等多种现代高精度分析测试手段,聚焦铀矿物种类、矿物共生组合关系、铀矿物成分特征及铀的赋存状态开展了系统研究。结果表明,天门地区铀矿物主要以独立铀矿物形式产出,多为脉状和团块状沥青铀矿,含少量铀石。团块状沥青铀矿周围多见有黄铁矿生长,成分相对均一,受热液蚀变影响不明显,脉状沥青铀矿多与长石、绿泥石、方解石、金红石等密切共生,说明遭受了一定程度的后期流体改造,化学成分发生变化。团块状沥青铀矿中UO_(2)、SiO_(2)、CaO含量分别为83.35%、1.45%、7.59%,具有贫SiO_(2)、富UO_(2)和CaO的特点,而脉状沥青铀矿中UO_(2)、SiO_(2)、CaO含量分别为79.96%、5.19%、5.70%。铀矿化蚀变相关的矿物共生组合种类较多,关系复杂,具体包括铀矿物-绿泥石-金红石、铀矿物-赤铁矿-石英-长石、铀矿物-黄铁矿-石英和铀矿物-石英-方解石等4类。综合研究表明,苗儿山矿田天门地区加里东期花岗岩体内存在多种矿物共生组合关系,铀矿物特征也指示可能存在早晚不同期热液铀成矿作用。The research and prospecting of uranium mineralization in South China mainly focus on the Indosinian and Yanshanian granites,and a series of theoretical innovations and prospecting achievements in uranium mineralization were achieved.Miaoershan ore field is an important granite-type uranium ore field in South China,which has strong magmatic activity,the fault depression zone,structure,hydrothermal activity and alteration were widespread,the conditions for uranium mineralization are favorable.Tianmen area is located in the middle of the Miaoershan ore field.In recent years,uranium ore bodies were discovered in the Caledonian granites of this region through geological exploration.The typical samples of black massive uranium mineralization ores were collected in Tianmen area in this paper,and a variety of modern high-precision analysis methods such as optical microscope,scanning electron microscope,electron probe,comprehensive mineral analyzer and high-resolution micro-X-ray fluorescence spectrometer were used to study uranium mineral species,mineral symbiotic association,uranium mineral composition characteristics and uranium occurrence state.The results indicate that uranium minerals are mainly in the form of independent uranium minerals,such as vein and massive pitchblende and a small amount of coffinite.The composition of massive pitchblende is relatively homogeneous,and is rarely affected by significant hydrothermal alteration.Vein pitchblende is closely associated with feldspar,chlorite,calcite and rutile,and the chemical composition of them changes due to the later fluid modification.The average values of UO_(2),SiO_(2)and CaO in massive pitchblende are 83.35%,1.45%and 7.59%,respectively,which have the characteristics of SiO_(2)-poor,UO_(2)-rich and CaO-rich.While the average values of UO_(2),SiO_(2)and CaO in vein pitchblende are 79.96%,5.19%and 5.70%,respectively.In addition,coffinite is closely related to pitchblende,which may be due to the change of pH and Eh and the solubility of SiO_(2).With the water-r

关 键 词：铀矿物特征 沥青铀矿 赋存状态 加里东期花岗岩 天门地区 

分 类 号：P619[天文地球—矿床学]