摘要
为探讨新类型"盆内隆缘式"富铀地层微量元素地球化学特征和铀的富集规律,选取松辽盆地XX地区四方台组富铀砂岩地层进行野外踏勘和系统采样,对研究区东西方向4个钻孔剖面含矿砂岩和不含矿砂岩进行了岩石学、矿物学和微量元素地球化学分析。结果表明,铀主要在长石岩屑砂岩中富集,并且靠近铀富集层位的岩石类型在横向上、纵向上呈规律性变化。稀土元素北美页岩标准化配分显示,围岩、矿化砂岩和富铀砂岩均呈右倾,具有轻稀土富集特点,并且轻稀土组分内部分异弱于重稀土;富铀砂岩δEu呈正异常,可能由富含斜长石所致;δCe基本无异常或略显负异常。富铀地层砂岩中的微量元素Grant等位线法分析表明铀初级富集过程中,微量元素大多表现为迁入,尤其稀土元素整体基本上是迁入,在再次富集过程中,微量元素迁出组分增加,尤其稀土元素整体表现为迁出,这反映铀的两次富集过程中的水解作用强度不同,后者较弱。
In order to discuss the geochemical characteristics of trace elements and uranium enrichment regularity of the U-rich bed in Sifangtai Formation in the Songliao Basin,the field geological investigation and systematic sampling have been carried out.Samples of non-mineralized and uranium mineralized sandstones of Sifangtai Formation,systematically selected from drill cores of 4 EW-striking profiles in the study area,have been studied in petrology,mineralogy,and trace element geochemistry.The results show that uranium is mainly enriched in feldspar lithic sandstones.The rock types of strata closing to the U-rich bed are changed regularly in both horizontal and vertical directions.The North American Shale standardized REE distribution patterns of wallrocks,uranium mineralized sandstones,and uranium-rich sandstones are all right-inclined,with the LREE enrichment feature and relatively weak internal fractionation of the LREE comparing to that of the HREE.The uranium-rich sandstones have positive Eu anomalies,which may be caused by high contents of plagioclase,but have no or slightly negative Ce anomalies.The Grant equipotential line analysis of trace elements in uranium-rich stratum sandstones shows that most trace elements,especially whole rare earth elements,are migrated into the sandstone in the primary uranium enrichment process whereas trace elements were gradually migrated out,especially the REE were wholly migrate out,in the second uranium enrichment process,reflecting the difference of hydrolysis intensity between two uranium enrichment processes,with the relatively weak hydrolysis intensity for the later process.
作者
魏帅超
邹妞妞
付勇
李建国
汤超
魏佳林
WEI Shuai-chao;ZOU Niu-niu;FU Yong;Li Jian-guo;Tang Chao;Wei Jia-lin(School of Resources and Environments,Guizhou University,Guiyang 550025,China;Institute of Hydrogeology and Environment Geology,Chinese Academy of Geological Sciences,Shijiazhuang 050061,China;Tianjin Center,China Geological Survey,Tianjin 300170,China)
出处
《矿物学报》
CAS
CSCD
北大核心
2019年第6期697-708,共12页
Acta Mineralogica Sinica
基金
国家自然科学基金项目(批准号：41802174)
贵州省科技厅计划项目(编号：黔科合基础(2019)1119)
贵州大学2017年度学术新苗培养及创新探索专项(编号：黔科合平台人才[2017]7285)
贵州大学引进人才科研项目(编号：贵大人基合字(2016)82号)
贵州省人才基地项目(编号：No.RCJD2018-21)
中国地质调查局天津地质调查中心地质调查项目(编号：DD20160128-02-02)
关键词
松辽盆地
地球化学
砂岩
富铀地层
稀土元素
the Songliao Basin
geochemistry
sandstone
uranium-rich stratum
rare earth elements(REE)
