《铀资源地质学》07澳大利亚铀矿实例介绍

Australia’suraniumgeology,resourcesandpotentialAustralianGovernment

GeoscienceAustraliaIanLambert,AdenMcKay,YanisMiezitis&SubhashJairethGeoscienceAustralia,Canberra

ThenationalgeoscienceandspatialinformationagencyOutlineofpresentationGeoscienceAustralia’srolesinrelationtouraniumAustralia’suraniumresources,productionandexportsandglobalcomparisonsTypesofuraniumdepositsinAustraliaandglobalcomparisonsDescriptionsofAustralia’smainuraniumdepositsMoreinformationonsandstonetypedepositsandISLinlaterpresentationsReasonwhyAustraliahassomuchuraniumFutureglobaluraniumsupplyanddemandUranium:GeoscienceAustralia’s(GA)rolesGAprovidestechnicalinputsinsupportofuraniumpolicyandinrelationtoEnvironmentImpactAssessmentsforuraniumprojectsGAobtainsinformationfromallexplorationcompaniesandreportstogovernmentonuraniumexploration,discoveryandresourcesArequirementundertheAtomicEnergyActGAproducesannualestimatesofnationalresourcesofuraniumBasedoncompanyreportingtostockexchangeAllrequiredtousethesamecodeforreportingreservesandresources(JORC)GAmakesnon-confidentialinformationavailableonlineTheGroupIleadhasresponsibilitiesforuraniumandover30additionalmineralcommoditiesproducedinAustralia,andotherissuesInvolvementinOECD/NEA-IAEAUraniumGroupGArepresentsAustraliaattheUraniumGroup(ViceChair)JointinitiativeofInternationalAtomicEnergyAgencyandtheOECDNuclearEnergyAgencyCollatingandanalysinginformationonuraniumresources,productionanddemandfromover40countries

biennial“RedBook”2005reportinpressOrderformsavailablesoononlineat:www.nea.frInvolvementwithIAEA

MycolleagueAdenMcKayhasbeenprovidingInputtotheIAEAdatabaseonworlduraniumdeposits(=UDEPODatabase)Morethan880Udepositsin57countriesIncludesdepositswithresourcesofmorethan500tUandaveragegradeofmorethan0.03%UUDEPOisbeingupdatedandexpandedcontinuouslyAvailableonlineatwww-ParticipationinIAEATechnicalWorkshopsIndia(AdenMcKay)ChinaProbablySouthAmericaText-28ptAustralianMinesAtlasOnline

.auTheMinesAtlascontainsGeneralInformationaboutUranium,aswellinformationabouttheUraniumIndustryinAustraliaLandsatimage,OlympicDamResourceInformationisavailableaswellasInternetlinksformoredetailedindustryinformationLatestassessmentofAustralia’suraniumresourcesUsingtheterminologyoftheUraniumGroup,Australiahas:ReasonablyAssuredResources(RAR)recoverableatcostsuptoUS$40/kgU(<US$15/lbU3O8)=“Lowcostcategory”ofUraniumGroup716,000tU(December2005)36%ofworldresourcesinthiscategoryOlympicDamalonecontains~26%ofworldtotalRARuptoUS$$80/kgU(belowcurrentspotprices)732,000tUReasonablyAssuredResourcesfortop10uraniumresourcecountriesUraniumresourcesbymine/deposit

Intotal,about85knownuraniumdepositsrangingfromsmalltosuperlarge

Explorationexpenditure,discoveriesandresourcesAustralia’suraniumproductionAustralia’suraniumproductionhasincreasedprogressively

since1976Australiaproduced11,222tU3O8in200522%ofglobalproductionSecondbehindCanada(~29%)Kazakhstanthird(9%,increasingrapidly)Rangermine=largestproducerinAustralia5910tU3O8in2005OlympicDam4335U3O8Beverley977tU3O8Australia’suraniumexportsAllofAustralia’smineproductionofuraniumisexportedunderlong-termcontractstocountrieswithwhichwehavenuclearsafeguardsagreement

US,Japan,EU,SouthKorea,CanadaSafeguardsAgreementsignedwithChinesegovernmentinApril2006FederalgovernmentpermitrequiredforalluraniumexportsfromAustraliaSecondarysuppliesofuraniumWorldmineproductionofuraniumcurrentlyonly=~60%ofdemand.Remainingdemand(~40%)ismetfromsecondarysourcesofsupply.Despitetheimportanceofthesesecondarysources,thereisuncertaintyaboutquantitiesAvailabilityornon-availabilityofsecondarysuppliescansignificantlyinfluencemarketSecondarysupplieslikelytobemuchdepletedby~2020.MostimportanturaniumstylesinAustralia

3.Sandstone4.Calcrete/Surficial1.Hematitebrecciacomplex(IOCG)2.UnconformityAustralia:UGrade/Tonnage/Contained

U

MainUmineralsindifferenttypesofdeposits

Unconformitytype

=Uraninite/PitchblendeUO2>CoffiniteU(SiO4)1-x(OH)4xHematitebreccia

=Uraninite/Pitchblende>Brannerite(U,Ca,Ce)(Ti,Fe)2O6Sandstonetype

=Coffinite;UraniniteCalcrete=CarnotiteK(UO2)2(VO4)2.3H2OVolcanic

=Uraninite;U-MomineralsMetasomatic,magmatic=BranneriteAustralia’suraniumdeposits

3minesand~85depositsDistributionofknowntypesofuraniumdepositsNosignificantQuartzpebbleconglomeratetypeU-AudepositsknownAustralia’sUraniumresourcesbytypeofdepositComparison:AustraliaandworlddistributionofuraniumresourcesbydeposittypesU3O8(t)Unconformityrelateduraniumdeposits,NorthernTerritoryNosignificantQuartzpebbleconglomeratetypeU-AudepositsknownUnconformityrelatedtypeUnconformity-relateddepositmodelMineralisationInAustraliaisnotknownaboveunconformity.

Itoccursatafavourablestratigraphicpositionbelowunconformity-inbrecciatedgraphitic-chloriticschistimmediatelyabovedolomiteunit(nowlargelymagnesite).Faultspresent.Unconformity-relateduranium,Kakaduregion,NTDeanHoatson,GAAllknownuraniumdepositsbeneathunconformityandnearedgesofsandstone.

Localisedinbrecciasalongfavourabledolomite-graphiticschistboundaryAboriginalrockpaintingsitesKakaduNationalParkRangermine:EarlyProterozoicunconformityURangerMillUnconformityNotehorizontalsandstoneandunconformityTailingsdisposal-RangerNo.1opencut

RangerNo3openpitRangerNo.3opencutRangermine:Mineralisedchloritic-graphiticbrecciaatgraphiticschist/dolomitecontactJabilukaLeaseandRangerProjectAreaJABILUKAJabiluka1and2OrebodiesUraninite-goldmineralisationisstrataboundSeveralagesofunconformityrelatedUmineralisationinPineCreekInlier~1620-1740Ma~1620Ma~780Ma~1620Ma–

ApproxUmineralisationageDistributionofknownU-richbedrocks,PineCreekInlier

.Uraninitepresentingraniteswithelevateduraniumcontents.UraniumissolubleinoxidisedwatersandprecipitatedbyreductionSomekeyissuesArelargeunconformityUsystemsconfinedtoPalaeoproterozoic-ArchaeanbasementunderlargelyundeformedPalaeo-Proterozoicsandstones?AreAthabascaBasininCanadaandPineCreekinAustraliaonlyexamples?Whatistheroleoffaultingandcarbonatedissolution?Didweatheringbeforedepositionofthesandstonemobilisemetalsand/orprovideapermeablezoneforfluidmigration?WhatisthesignificanceoftransitionfromgenerallyreducedtooxidisedconditionsintheEarlyProterozoic?UnconformityrelatedUsystemsEmphasisofrecentresearchonaquifers/UsourcesincoversandstonesHistoricresearchmainlyonstratigraphy,reducingrocks,structuraltrapsinPineCreekbasementPalaeoweatheringzoneUraniumdeposits:HematitebrecciacomplextypeHematitebrecciacomplextypeLocationplanandsimplifiedregionalgeologyoftheGawlerCratonandStuartShelf,SouthAustralia(afterReeve&others,1990)ProminentHillxHematiteBrecciaComplexDepositsHematitebrecciacomplexUdepositsOnlyknowninSouthAustraliaGawlerandCurnamona

cratonsOlympicDamisbyfarlargestexample

Cu–AuwithUco-product=memberofIronOxideCu-AusuiteofdepositsGranitoidsinregionareoxidised,havehighU,highK2O/Na2O,and

60-77wt%SiO2OlympicDamU-Pbagedatingshowsgraniticintrusion,volcanism,brecciationandmineralisationarecontemporaneousat~1590Ma

OlympicDamexpansionplansProposedopenpitOlympicDam:

HematitebrecciacomplexuraniumdepositBrecciaandmineralisationformedinexplosivevolcanicsetting~300mcover

(Phanerozoic)OlympicDamPlan04-029-8Alterationtypes(fromSkirrow,Bastrakov,Raymondetal.,2002)

OlympicCu-Au±UprovinceBD1SAE7Magnetite–alk

feld–calcsilMagnetite–biotite

+Cu-Au~1585Ma~1575-1590Ma~1580MaHematite–ser–chl–carbCu-Au-UHmoverprintingmagnetiteU~1585Ma~1590MaGranite(young)Granite(old)~1.64to1.55GaMountPainterComplex(~1.73to1.68Ga)HematiticbrecciaMountGeeBrecciaComplex,SA(0.03mtU;minorCu)InhillstowestofBeverleysandstoneUdepositSomefeaturesofhematitecomplextypeUdepositsHematitebrecciacomplexuraniumsystems=uraniferousironoxidecoppergolddeposits(IOCGs)OlympicDamisbyfarlargestexampleCriteriathatdistinguishuranium-richIOCGsfrom(morecommon)uraniumpoorIOCGs:Explosivevolcanicactivity;regionalfaultsand/ordiatremeventzonesRegionalNa(K)-Ca,and/orironoxidealteration;hematitealterationoverprintingmagnetitealterationHighpalaeo-geothermalgradients(stillsomewhatelevated)andlargevolumesofU-enrichedfelsicintrusiveandvolcanicrocks

(I-type,oxidised,highheatgranites);Uraniumdeposits:SandstonetypeSandstonetypeSandstoneuraniumdeposits:

LakeFromeEmbaymentBeverleyuraniumrecoveryplant-ionexchangetechnology

Beverley-commercialinsituleachwellfieldBeverleySandstoneU:GeologicalsectionU-richProterozoicgranites,FromeEmbayment

U-richgranitesUraniumdeposits:Surficial(Calcrete)typeNosignificantQuartzpebbleconglomeratetypeU-AudepositsknownSurficialtype(calcrete)Yeelirrie:

CalcretetypeUraniumcontentsofsomerocksandwatersArenitesaverage1.5ppmPelitesaverage3.5ppmEvaporitesaverage0.1ppmPhosphoritesupto300ppmWeatheringproducts(laterite/bauxite,etc.)average10ppm

Biotiteandgraphiticschists,average~4ppmGneisses~3.5ppmGranite~5ppmAlkalineigneousrocks10s–100sppmGroundwatersinigneousandmetamorphicterranes

average5-10ppbMineralisedaquifer10-400ppb

Note:Igneousrocks/gneisseswithmorethan~10ppmUtypicallycontainuraninite,whichisreadilyleachedGeologicalprovincesandfelsicigneousrocksofdifferentagesU-richrocksfromnationalgeochemicaldatabaseGeoscienceAustraliaUmineralisationandfelsicigneousactivityHotSouthernContinentÌÌÌÌÌÌÌÌOlympicDamBrokenHillCanningtonCenturyHYCTheGranitesRangerTelferÌMountIsaHighproportionofU-richfelsicigneousrocksareProterozoichighheatflowsPowerfromhotgranitesUranium-richgranites

250oCat3-5kmdepth.

Goodpotentialforgeothermalpowergeneration.SeveralpilotprojectsinSouthAustralia.ProterozoicHighHeatFlowGranitoidsAustralianCratonwasassembledby~2300Ma.Metallogenycontrolledbyintracratonicbasinsgeneratedbymantleunderplating.Anorogenic

magmatismRegionswithsignificantUdepositsandpotentialUnconformityCalcreteHematitebreccia,sandstoneSandstoneHematitebreccia,sandstone,Unconformity,IntrusionrelatedPineCreek,McArthurBasinYilgarnPatersonGranites-TanamiNgalia,AmadeusGawler,Curnamonacratons,overlyingbasinsMtIsaInlier,adjacentbasinsGeorgetown,ChartersTowers’VolcanicCarnarvonBasinCanningBasinSandstoneMcArthurBasin???IntrusionrelatedinArunta??IOCGUnconformitySandstoneCalcreteVolcanicIntrusionSomeresearchobservations:

Mineraldepositsthroughtime

OxidisedatmosphereFractionatedcrustProg.oxid’noceanResearchobservations:

Archaean-earliestProterozoic:uraniuminquartzpebbleconglomerateUraniuminsolubleinreducedwaters-

detritaluraninite(+pyrite+gold):SouthAfrica,

CanadaMetamorphicoverprintsPrevalentdistributionofmajortypesofUdepositsthroughgeologicaltimeFromFDahlkamp(1993)GlobaluraniumsupplyanddemandforecastsEventhemostconservativeofinternationalscenariosimplythatnuclearpowerwillbesustainedatleastatcurrentlevelsThisrequiresprogressiveincreasesinmineproductionofuranium,assecondarysuppliesaredepletedIncreasingnuclearpowergenerationappearslikely,asvariouscountriesimplementstrategiestodecreasegreenhouseemissionsThiswillproportionallyincreasethedemandforuraniumUpperscenarioofWorldNuclearAssociationhasuraniumdemanddoublingby2025GlobaluraniumsupplyanddemandforecastsSignificantlyincreasedproductionhasbeenforeshadowedfrom:Canada(openingofthemajorCigarLakemine)Kazakhstan(developingseveralnewsandstonetypedeposits)Australia(developingalargeopenpitatOlympicDamtoincreaseproductionuptofourfold)Ifrealised,theplannedincreasesshouldgoalongwaytowardsmeetingthedemandassecondarysuppliesdecreaseThereisaneedforfurtherexplorationtosustainuraniumresourcebaseParticularlyfrom~2020SummaryAustraliahas~37%ofworld’slowcostresourcesAustralianuraniumdepositsformedinthreemainperiodsSpatialassociationbetweenUmineralisationand

U-enrichedfelsicigneousrocksSomedepositsformedduringigneouseventseg.hematitebrecciacomplex,intrusive,volcanic&caldera-relatedtypesOthersformedsubsequently,whenuraniumwasmobilisedfromU-enrichedigneousrocksand/orderivedsedimentseg.unconformity-related,sandstone,calcretetypesSummary(cont.)Australiahas:ConsiderablepotentialfornewdiscoveriesandFavourableconditionsforminimisingtheenvironmentalandsocialimpactsofminingItisinevitablethattheinternationalcommunitywillbelookingincreasinglytoAustraliatosustainitsvitalroleinprovidinguraniumforfuturenuclearpowergenerationAustraliaalsohasmajorthoriumresourcesIncreasinginterestinTh-fuelledreactorsUraniumdepositstylesHaematiteBrecciaUnconformitySandstoneSurficialGeodynamicsettingAnorogenic/Arc??BasininitiationIntermontanebasinwithlocalbasins,palaeochannelsPresentlandsurfaceArchitectureDiatreme/

maarBasalunconformityConfinedaquiferwithreductantsLowgradientariddrainageDrivers&PathwayHighheat.BrecciasTectonic/thermal.

Aquifers,breccias,faultsAquifers+/-faultsErosion+topographyFluidandmetalsourcesOxidisedhighUgranites+meteoric?Basinalbrines/meteoric.Ox.HighUrocks(granites/sst)Meteoric.Ox.highUgranitesMeteoric.

Ox.HighUgranitesMetalDepositionRedoxRedoxRedox/strat.trapChemicalprecipitationSpeciationofUInsurficialenvironment

(fO2>Hmt)UO2+2(Uranylcomplexes)Carbonate,sulphate,chloroandphosphateUdepositsbyreductionFe+2Fe+3FeS2Fe2O3U-boundariesat0.24ppmUSolubilityincreasesGeologyofAustraliaArchProtPalProgressiveyoungingfromWE0.42mtU3O81.64mtU3O80.04mtU3O80.05mtU3O8UraniumResources

0.03mt