投稿时间：2018-04-13
修订日期：2018-11-23
网络发布日期：2019-07-03
中文摘要:为揭示尼日尔阿泽里克铀矿床成矿物质来源，文章研究了其蚀变特征、稀土元素特征、流体包裹体特征、方解石胶结物碳和氧同位素特征、沥青铀矿氧同位素特征等。阿泽里克铀矿床发育灰绿色还原蚀变、方沸石化、酸性火山玻璃脱玻化、碳酸盐化、黄铁矿化、重晶石化等。矿化砂岩稀土元素Eu强正异常。流体包裹体气体成分为H2+N2+CO2组合。方解石胶结物的δ13CV-PDB值为-7.45‰~-6.65‰，δ18OV-SMOW值为-0.74‰~1.26‰。沥青铀矿的δ18OV-SMOW值为-1.30‰~-0.8‰。灰绿色还原蚀变岩石呈灰绿色是因为绿泥石矿物充填粒间孔隙和包裹颗粒表面。矿化砂岩的Eu强正异常揭示有来自深部的强还原性流体参与成矿。H2为强还原物质，来自深部，可为铀成矿提供还原剂。矿化砂岩方解石胶结物碳同位素显示成矿流体有深部流体的作用，可能有地幔物质的加入；氧同位素显示成矿流体有表生流体的作用。沥青铀矿氧同位素值显示成矿流体受表生大气水作用影响。酸性火山物质方沸石化和酸性火山玻璃脱玻化为铀成矿提供铀。成矿流体为表生氧化性流体与深部的还原性流体的混合。总之，地层、阿伊尔花岗岩和火山物质可能为铀成矿提供了铀。
Abstract:To reveal the source of metallogenetic material in the Azelik uranium deposit, the paper studied its features of alteration, REE geochemistry, fluid inclusion, C-O isotope of calcite cement and O isotope of pitchblende. Alterations are gray green reduction, analcimization, devitrification of acidic volcanic glass, carbonatization, pyritization, chalcopyrite, baritization, et al. The genesis of gray green of reduction is chloritization. Analcimization and of acidic volcanics and devitrification of acidic volcanic glass provided uranium for mineralization. Positive anomaly of Eu from mineralized sandstone reveals that reductive fluid from the deep was involved into mineralizing. Gaseous compositions of fluid inclusions are H2, N2 and CO2, which present the character of gaseous compose from the deepth, and H2 is a type of strong reductive agent which provided reductive material for mineralization. Isotopic of C from calcite cement of mineralized sandstone shows that fluid from the deep was involved which maybe contains material from the mantle. Isotopic of O from calcite cement of mineralized sandstone and pitchblende show that hypergene meteorological fluid was involved. Metallogenetic fluid is the mixture of reductive fluid from the deep and oxidized fluid from the hypergene. Uranium is provided by stratum and the Aïr granite mass and vitroclastic tuffs may provide uranium for mineralization.
keywords:geochemistry sandstone type uranium deposit source of metallogenetic material analcimization devitrification Azelik deposit in the Niger
文章编号：
中图分类号：P619.14
文献标志码：
基金项目:本文得到核能开发项目"准噶尔大型叠合盆地地浸砂岩型铀矿预测技术研究"、"非洲中南部古老地块铀矿综合识别评价技术及应用研究"、地质调查项目（编号：DD2016013628、DD20190813-7）联合资助
引用文本：
许强,秦明宽,范洪海,顾大钊,李娟,何中波,刘章月,黄少华.2019.尼日尔阿泽里克铀矿床蚀变及地球化学特征——对成矿物质来源的约束[J].矿床地质,38(3):667~684XU Qiang,QIN MingKuan,FAN HongHai,GU DaZhao,LI Juan,HE ZhongBo,LIU ZhangYue,HUANG ShaoHua.2019.Features of alteration and geochemistry of Azelik uranium deposit of Niger: Restraint to source of metallogenetic materials[J].Mineral Deposits38(3):667~684
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