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1、第22卷第2期中国有色金属学报2012年2月Vol.22No.2TheChineseJournalofNonferrousMetalsFeb.2012文章编号:1004-0609(2012)02-0546-07黔东南州下寒武统黑色页岩稀土元素地球化学特征1,21,21,21,2,31,2侯东壮,吴湘滨,刘江龙,吴德华,葛丽萍(1.中南大学有色金属成矿预测教育部重点实验室,长沙410083;2.中南大学地球科学与信息物理学院,长沙410083;3.湖南城市学院城市建设系,益阳413000)摘要:采用等离子质谱
2、仪(ICP-MS)对三穗和黄平下寒武统斜坡相黑色页岩稀土元素含量进行分析。结果表明:−6−6−6稀土总量为68.28×10~252.00×10,平均含量为133.16×10;ΣLREE/ΣHREE的比值是2.38~5.70,轻稀土元素较重稀土元素富集。δEu=0.49~0.75,推测沉积温度低于250℃;δCe=0.34~0.85,反映岩石是在相对缺氧的海水环境条件下沉积。岩石(La/Sm)N的比值是1.77~3.31,代表有地下深部物质加入。黑色页岩稀土的球粒陨石配分曲线为向右倾斜,而其北美页岩组合样标准
3、化曲线明显呈近于水平或左倾。结合La/Ce和La/Yb-REE判别图解,推断黔东南州黑色页岩形成于一种干燥缺氧较深浅海环境,并在形成过程中有热液参与。关键词:稀土元素;地球化学特征;黑色页岩;下寒武统;黔东南州中图分类号:P595;O614.33文献标志码:AGeochemicalcharacteristicsofrareearthelementsinLowerCambrianblackshaleinSoutheastQian11,21,21,2,31,2HOUDong-zhuang,WUXiang-bin
4、,LIUJiang-long,WUDe-hua,GELi-ping(1.KeyLaboratoryofMetallogenicPredictionofNonferrousMetals,MinistryofEducation,CentralSouthUniversity,Changsha410083,China;2.SchoolofGeosciencesandInfo-Physics,CentralSouthUniversity,Changsha410083,China;3.DepartmentofUrban
5、Construction,HunanCityUniversity,Yiyang413000,China)Abstract:Theabundancesofrareearthelements(REE)oftheblackshaleontheslopefaciesfromLowerCambrianinSansuiandHuangpingweremeasuredbyusinginductivelycoupledplasmamassspectrometry(ICP-MS).Theresults−6−6−6showth
6、atthetotalREEcontentis68.28×10−252.00×10,theaverageoneis133.16×10;theratioofΣLREEtoΣHREEis2.38−5.70,whichshowsthatLREEarerelativelymoreintensivethanHREE.δEu=0.49−0.75,whichshowsthatthedepositiontemperatureisbelow250℃.δCe=0.34−0.85,whichreflectsthatarockdep
7、ositsundertheconditionofrelativelyhypoxicsea.Theratioofrock(La/Sm)Nisbetween1.77and3.31,whichrepresentsthatithasaddedwiththematerialsfromdeepresource.Thechondritenormalizedpatternsofblackshaleinclinetotheright,theNorthAmericanshalenormalizedREEpatternsofsi
8、liceousrocksarenearlyflatorleft.CombinedwiththediscriminationdiagramsofLa/CeandLa/Yb-REE,theblackshaleofSoutheastQianformedinadry,hypoxiaandshallowsea,withtheparticipationofsomehydrothermalfluidsintheformatio