平庄盆地黑水地区氧化作用与铀成矿地质特征  

Oxidation and geological characteristics of uranium mineralization in Heishui area,Pingzhuang Basin

作　　者：董方升 彭虎 张成勇[3] 王生文 张松 安永海 DONG Fangsheng;PENG Hu;ZHANG Chengyong;WANG Shengwen;ZHANG Song;AN Yonghai(Liaoning Province Geology and Minerals Group Energy Geology Co.,Ltd.,Shengyang 110000,Liaoning,China;China University of Geosciences,Wuhan 430074,Hubei,China;Fundamental Science on Radioactive Geology and Exploration Technology Laboratory,East China Institute of Technology,Nanchang 330013,Jiangxi,China)

机构地区：[1]辽宁省地矿集团能源地质有限责任公司,辽宁沈阳110000 [2]中国地质大学(武汉),湖北武汉430074 [3]东华理工大学放射性地质与勘探技术国防重点学科实验室,江西南昌330013

出　　处：《地质通报》2023年第5期687-699,共13页Geological Bulletin of China

基　　金：辽宁省省级基金项目《辽宁铁法-昌图盆地砂岩型铀矿地质调查》(编号:JH20-210000-05760)、《辽西北地浸砂岩型铀矿成矿地质条件研究》(编号:JH20-210000-05760)。

摘　　要：黑水地区位于平庄盆地北部,砂岩型铀矿找矿目的层为白垩系孙家湾组,目前在盆缘发现了较好的氧化带和工业铀矿化线索,但成矿作用方式和类型并不清楚,困扰着下一步勘查方向的选择。为深入研究目的层氧化作用和铀成矿地质特征,通过系统采集样品,进行镜下鉴定、主量元素、环境地球化学指标、粘土矿物、电子探针、扫描电镜等分析。研究结果表明,黑水地区含矿目的层砂岩成熟度较低,为近物源沉积;后生氧化作用较强且存在明显的蚀变分带现象;目的层还原剂主要为黄铁矿,铀的富集方式主要为含铀含氧水不断渗入砂体,在层间氧化带前缘氧化还原过渡带富集成矿,铀矿物类型主要为沥青铀矿,其次为铀石,主要有2种赋存形式。对铀成矿地质特征进行探讨,认为该地区符合层间氧化带型砂岩型铀矿成矿模式,具有较大的成矿潜力。The Heishui area lies in the northern Pingzhuang Basin,where the Cretaceous Sunjiawan Formation is targeted for uranium exploration.Better oxidized zones and industrial uranium mineralization have been observed on the margins of the basin in recent years.However,the choice of the next exploration direction puzzles us because the pattern and type of mineralization are still unclear.To improve our understanding of the oxidation of aim stratum and geological characteristics of uranium mineralization,we conducted an integrated analysis of samples collected in study area,including microscopic identification,major element,environmental geochemical indicators,clay minerals,EPMA,and SEM in this study.The results show that the maturity of sandstone of ore bearing aim stratum is low,indicating a proximal provenance.There is strong post-growth oxidation and significant alteration zoning.Furthermore,the target layer reductant is dominated by pyrite.The uranium enrichment pattern is that uranium-oxygenated water continuously infiltrates the sand body.Enrichment and mineralization occurred in the oxidation-reduction transition zone of the frontal interlayer oxidation zone.Pitchblende,followed by coffinite,is the predominant uranium mineral type.The geological characteristics of the uranium mineralization in the study area are in accord with oxide zone-stratified sandstone-type uranium mineralization model,which has a high potential for mineralization.

关 键 词：砂岩型铀矿 氧化作用特征 铀矿化特征 铀成矿地质特征 平庄盆地 黑水地区 

分 类 号：P619.14[天文地球—矿床学]