简介：TheauthorshavedetailedlyandsystematicallystudiedthecarbonisotopiccompositionofEarlyProterozoiccarbonaterocks.SampleswhicharealldolomicriteweretakenfromtheJianancun,DaguandongandHuaiyincunFormationsoftheHutuoGroupinWutaiCountyShanxiProvince,NorthChina.Atotalof209sampleswereanalysedfortheircarbonisotopecompositions,andthemeansamplingintervalwas6.9m.Carbonisotopeanalysisclearlyshowsδ13CshiftsattheboundarybetweentheJian’ancunFormationandDaguandongFormationandneartheboundarybetweentheDaguandongFormationandHuaiyincunFormation.LikecarbonisotopeshiftsattheCretaceous-Tertiary,Permian-TriassicandPrecambrian-Cambrianboundaries,thediscoveryofδ13CshiftsintheEarlyProterozoichasimportantsignificanceinfurtherstudiesonEarlyProterozoicbioticevolution,regionalandglobalstratigraphiccorrelation,andcarbongeochemicalcycles.

简介：TheeditorsofthisvolumeassembledaremarkablegroupofcontributorstodiscussboththegeologyofEastGondwanaandalsomanyrelatedissues.The19papersinthisbookprovideawealthofinformationonEastGondwana,theassemblyofGondwanaasasupercontinent,theconfigurationofRodinia,andgeneralproblemsoftheoriginofcontinentalcrustandmovementofcontinentalplates.Theyalsoillustratesomeofthecontroversies,withmostpapershavingatleastsomepointsofdifferenceinbothfactandinterpretationfromotheroaoersinthebook.

简介：ThisstudyfocusesonthebasementstructureoftheParanáBasininSouthAmerica,basedongeologicalandgeophysicaldata.ItisalargeintracratonicbasinformedfromtheLateOrdovicianuntiltheCretaceous,whenasequenceofcontinentalfloodbasaltseruptionscoveredtheentirebasin,precedingthebreak-upofWesternGondwana.Isostaticmodelingwasappliedtolargegravitysurveyscomprisingmorethan12,000gravitystations.TheresidualBougueranomalypattern,representingthecrustalcontributionofthecrystallinebasement,aswellasthesedimentaryandvolcaniclayersofthebasin,revealssimilaritiesbetweenthebasementgravitysignatureandtheexposedrock.ThestresspatternsoftheLateOrdovicianandCretaceoustectoniceventspresentageographicallycoincidentmaximum,andthecorrelationbetweengravityhighsandthemainattenuation(betafactor)suggeststhepresenceofsomepreexistentsuturezones.TheresultantmosaicofgravityblocksandthelocationofmajorfaultsgivesupporttothepresenceofanimportantProterozoiccratonicfeature,herereferredtoasParanapanemablock.

简介：TheKuandianComplexisscarcelypreservedEarlyProterozoicvolcanicsuite,formed2.3-2.4Gaago.ItislocatedinanEarlyProterozoicmobilebeltboundedbytheArchaeanRangrimandRyonggangBlocksofthenortheasternSino-KoreanCraton.TheComplexismainlymadeupofamphibolites,gneisses,leucoleptite,leptiteandlayeredgranite.PetrologicalandgeochemicalstudiesshowthattheprotolithsoftheComplexaremainlyassoctationsofbimodalvolcanicsandanorogenicgranites.TheKuandianamphibolitesaredepletedinNb,Ta,PandTi,andenrichedinLILE,e.g.K,RbandCs,withpronounceddepletionofSrrelativetoNdandPb;La/Nbratiosarehigherthan1（1.75to5.18）.ThetraceelementpatternsoftheamphibolitesaresimilartocontinentalfloodbasaltsformedbytheGondwanabreak-up,suchasthoseinSouthKarooandTasmania,whichshowscontinentalcontamination.εNdvaluesrangingfrom0.70to1.94oftheKuandianamphibolitesandtherelationshipsbetweenNb/YbandLa/Ybsuggestthatcontaminationofbasalticmagmahappenedinthemantle,ratherthanalongtheconduit.Isotoperatiosof208Pb/204Pb,207Pb/204Pb,206Pb/204Pb,143Nd/144Ndand87Sr/86SrindicatethatthemagmawasderivedfromacontaminatedmantlesourcelikeDMMoramixtureofDMMandEM2.TheKuandianComplexhasDupalanomaly,asisthecasewithsomecontinentalbasaltsinthesouthhemisphere,e.g.inSouthKarooandTasmania.PetrochemicalmodellingproposesthattheKuandiangneiss,granite,andamphibolitecamefromthesameparentalmagma,beingproductsofstrongfractionalcrystallization.ProtolithsoftheKuandianComplexwereformedinextensionaltectonicsettingduringthetransitionfromcontinentalcrusttooceaniccrust.TheformationoftheKuandianComplexindicatesthat2.3or2.4GaagotectonicevolutionoftheSino-Koreancratonwasdifferentfromthatofotherwell-studiedPrecambriancratons,e

简介：TheJiangshan-Shaoxingfracturebelt(JSFB)isaLateProterozoicgeosutureduetoislandarc-continentcollisioninSouthChina,TheCathaysianBlock(CT),lyingonthesoutheastsideofJSFB,iscomposedofgreenschist-amphibolitecomplexesintheformofaseriesoftectonicflakes.OnthenorthwestsideofJSFB,whichislocatedintheborderareaofZheijiang,JiangxiandAhhhiprovinces(abbreviatedasZJP-JXP-AHP),aredistrbutedandophiolitesuiteandotherrocks,constitutingtheJiangnanancientislandarc(JN)onthesoutheastmarginoftheYangtzeBlock(YZ).ThecollisionbetweenJNandCTat-0.9GaagoledtothefoldingofJN.followedbytheintrusion(-0.9-0.8Gaago)ofmanydioriticandultramaficstitchingplutonsalongthefracturebelt.Asaresult,thebasicPrecambriantectonicframeworkofsoutheasternChinawasshaped.

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简介：<正>TheTongkuangyuporphyrycopperdepositintheZhongtiaoMountains,China,istectonicallylocatedonthesouthernmarginoftheNorthChinaplatformandonthenorthernmarginoftheLateArcheanZhongtiaoshanintracontinentalriftbasin.Thedepositoccursinacopper-bearingformationoftuffaceousvariegatedsandshale-K-richbimodalvolcanicrocksoftheTongkuangyuFormationoftheLateArcheanJiangxianGroup,andtheorebodiesarelocalizedinatransitionportionbetweentuffaceousvariegatedsandshaleandbimodalvolcanicrocks.Thehostrocksconsistmainlyofmetagranodiorite-porphyry,meta-quartzmonzonite-

简介：ThecarliestMiddleProterozoicmarkedthebeginningofaqualitativclynewstapeintheEarth’shistory,thatofptimarytectonomagmaticactivity(orproto-activity)whichstronglytcworkedoldercratons,shieldsandplatforms.Theactivitywasevidentinalmostallthecontinentsandspannedabout250Ma,from1900±100to1650±50Ma.Highratetect

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简介：SystematicgeochemicalstudiesoftheProterozoicLengjiaxiGroupinnortheasternHunanProvincesuggestthattheLengjiaxiGroupisaAu-As-Sb-Wassociation-typeAu-bearingturbiditeformation.ThecontentsofAu,As,Sb,W,Cr,Mn,PbandZnintheturbiditeformationaremorethantwotimesashighastheaveragecontentsoftraceelementsintheuppercontinentalcrust.ThelowabundanceofAgandtheclosecorrelationbetweenAuandAsaretwoimportantcharacteristicfeatures.IntheAu-bearingturbiditeformationtheenrichmentofgoldisduetotheextensiveoccurrenceofAu-bearingpyrites.HighercontentsofAu,W,SbandAginthegreywackeindicatethattheyalsoexistintheformofheavyminerals.Au,Ag,As,Sb,WandREEintheAu-bearingturbiditeformationhaveaclosegeneticrelationwiththechemistryofthegolddeposits.

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简介：ThethirdworkshopoftheIGCP450project“ProterozoicSediment-hostedBaseMetalDepositsofWesternGondwana”washeldattheDonBoscoTheologicumCenter,Lubumbashi(D.R.Congo)from14to24July2003.

简介：Tenrepresentativelimestonesamples[sixfromWangshanFormation(WL)andtheotherfourfromGouhouFormation(GL)]werecollectedfromoutcropsofthenorthernAnhuiProvince,andREEconcentrationsinlimestoneweremeasuredbyICP-MS.ThedepositionalenvironmentandsourceoftheREEwereanalyzed,andtheresultsimplysthatthetotalREEofsamplesarelowcomparedwiththerecentmarinesediments,whichrangefrom9.61to54.18mg/kgandanaverageof22.93mg/kg.ThePAAS-normalizedREE+Ypatternsoflimestonearecharacterizedby(1)lightREEdepletioninWLandenrichmentinGLwiththevaluesof(Nd/Yb)SNrangingform0.65to0.91and1.12to1.46,respectively;(2)lightnegativeCeanomaly(0.85–1.02)andpositiveLaanomaly(0.92–1.27);and(3)bothEu(0.91–1.23)andY(1.42–2.38)expressinglightpositiveanomaly.Thecharacterindicatedthatthedepositionalenvironmentwasoxygenated,withinfectionbythehydrothermalactivityandcontaminationofdetritus.

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