鄂尔多斯盆地东胜砂岩型铀矿微量和稀土元素地球化学特征

24420108GEOSCIENCEVol124No14Aug120101,2,1,3,2,1(11,,100083;21O,014010;31,S4S0A2):20091230;:20100625;::(40772061,40472054);(B07011);(IRT0755);(2003CB214606):,,,1985,,Email:xueweishenba@1631com:,,,,1962,,Email:chunji1xue@cugb1edu1cn:,,PbMoU,,,;PbMo,PbUMoWREE,HREE,():;;;;:P61914:A:1000-8527(2010)04-0776-09TraceElementandREEGeochemicalCharacteristicsofSandstone2typeUraniumDepositintheDongshengAreaoftheOrdosBasin,ChinaXUEWei1,2,XUEChun2ji1,CHIGuo2xiang3,PENGYun2biao2,WANGKai1(11StateKeyLaboratoryofGeologicalProcessesandMineralResources,SchoolofEarthSciencesandResources,ChinaUniversityofGeosciences,Beijing100083,China;21No1208GeologicParty,ChinaNuclearGeology,CNNC,Baotou,InnerMongolia014010,China;31DepartmentofGeology,UniversityofRegina,Saskatchewan,ReginaS4S0A2,Canada)Abstract:ThisstudyexaminesthegeochemicalcharacteristicsoftheDongshengsandstone2typeuraniumdepositintheOrdosbasininordertofindgeochemicalsignalsthatareusefulforuraniumdepositexploration.Traceele2mentanalyseswerecarriedoutforuraniumores,uranium2mineralizedsandstones,andnon2mineralizedcountryrock(sandstonesandshales).TheresultsindicatethatPbandMohavecloserelationshipswithuraniumminer2alization,withthehighestconcentrationsintheuraniumores,thenintheuranium2mineralizedsandstone,andlowestincountryrocks.Therefore,PbandMocanbeusedasindicatorelementsforuraniummineralization.ThisisreflectedbytheWpattern(threepeaksrepresentingPb,UandMo)inthespiderdiagram.REEpat2ternssuggestthattheores,mineralizedsandstonesandnon2mineralizedcountryrockswereinitiallyformedfromthesamematerialsources,sedimentaryenvironmentsandtectonicsettings.ThefactthatsomeoftheuraniumoresareenrichedinHREErelativetootheruraniumoressuggeststwostagesofuraniummineralization,adiage2neticstageoverprintedbyahydrothermalmineralization.Keywords:Ordosbasin;Dongshengsandstone2typeuraniumdeposit;traceelements;REE;geochemistry0250000km2,,[1-3][4][5][6-8][3],[9-10],[11-12],(),,1,,,,,,,,,[13],,[3],(,1),,1000m,,,,,(13),,[14]1([8],2009)Fig11AsketchgeologicalmapofthenorthernOrdosbasinandneighboringareasandthelocationofthestudyarea(modifiedafterXueWeietal[8],2009)2,,,,,,,,;,,2040m,,,;,;,,,[9],7774:11973120041,79m,,[15];,,[8],,[3,15],U2Pb4,177149Ma()124107Ma()8570Ma()208Ma()[16-17]3(),3(ZKA7/0ZKA95/11ZKA139/35)18,VGPQ2Tur2boICP-MS,121994[18],1968Haskin[19],1966Haskin[20]2()Fig12Aspiderdiagramoftraceelements(normalizedtoaverageChinesesedimentaryrocks)ofuraniumores,uranium2mineralizedsandstonesandnon2mineralizedsandstones(wallrock)intheDongshenguraniumdeposit,Ordosbasin;2CeEu1985Tayloretal1[21]:Ce=CeN/(LaNNdN)1/2,Eu=EuN/(SmNGdN)1/2,N4411,()23,,123,U,22317110-650112410-6,250;UPb(2912410-611814710-6)Mo(216910-61813110-6)Ba(77619910-693711910-6),;CsHfCuZrCo;Y,2(A95/11-09A95/11-10),2(A7/0-05A139/35-07),U(3116610-64518610-6),87720101(wB/10-6)Table1ThecontentofthemajortraceelementsfromvariousgeologicalbodiesintheDongshenguraniumdeposit,Or2dosbasin(10-6)CrCoNiCuZnGaRbSrYZrNbA7/0205A95/11209A95/11210A139/3520712343211191151611051852214410181621782821551210239181518550120111152218517128391641212175149279116771964515681044914118131301879127261901119871146292135621286318481816515515115241747185401631510180171344196131805919110104A7/0202A7/0206A139/35205A139/3520645671231472719235159151769018618139791143011731413710015711186321147192111678199251329175651182451361616751187517740171910314194101052811312143751193071191014843124618536137716615170715039195111246513330214619125311005117A7/0203A7/0204A95/11207A139/35208A95/11206A95/11204A95/11203A7/0207A139/35204A139/3521091011121314151617185612471501915219102321101211369115279122813663159912534143714018112171762419210148621702671732014353172518935109618313126101272818311190761252871652414840181613312016317135281241112854130161849417730918881925511910107119121381404319831124197184141603818132016628118601961016810718221131491993013594117231151011543101312211392198151419415551842618944161351462615399112343135201481061912017799120201464115425116136199231888512331014717153185127161731301432917854163381531661832312810015133713628115931901618610916235115581204511095189191737017235014837101811521217052100331002510028100451001310095100330100201001301009190MoSnCsBaHfTaPbBiThUA7/0205A95/11209A95/11210A139/352071234181311116110477619911160141291240108315622317161051014111259371191138015840114011251144621344153116211278071991170015530114010791852921162169116811919151711174016611814701095189501124A7/0202A7/0206A139/35205A139/352064567719221462170742120210001733310101148146451865159112211197591081142013714138010941324212711761616311537991981135014438103011041563116611232100111375916201940137211600108312936161A7/0203A7/0204A95/11207A139/35208A95/11206A95/11204A95/11203A7/0207A139/35204A139/3521091011121314151617180172101761121853112117001632811601116101413601787102019578513211500141251760110319821540174019711558361541121014310178010731552178110111922141962127116001652213301105158818911661180216336012611600170191400121111212145017021445175672156214601961918701331311221271106314614106559111218011362913