简介：Datingofmetallicoredepositshasbeenoneoftheproblemsconcernedwithbyoregeologistsformanyyears.TheestablishmentoftheRe-OsIsotopeLaboratoryattheInstituteofRockandMineralAnalysis,ChineseAcademyofGeologicalSciences,hasprovideduswithanewtechniquetocarryoutgeochronologicalstudiesofmolybdenumores.AsoneofthemostimportantRe-bearingminerals,molybdenitecontainsalmostnocommonosmium,but^187Oswasderivedcompletelyfromdecayof^187Re,with^187OscontentasthefunctionofRecontentinthemineral.AnID-ICP-MStechniquehasbeenusedinthisstudy,andRe-Osisotopicagesofseverallargemolybdenumdepositsofdiffer-enttypesfromtheEastQinlingmolybdenumbelthavebeendetermined.ItisindicatedthattheHuanglongpucarbonatitevein-typemolybdenum-(lead)deposithasaRe-OsagecorrespondingtoIndosinian,whiletherestporphyry-typemolybdenumdepositsandporphyry-skarn-typemolybdenum-(tungsten)depositshaveRe-OsagescorrespondingtoYenshanian.

简介：　　四川力马河镍矿是峨眉山大火成岩省一个有代表性的岩浆硫化物矿床,岩体主要由辉长-闪长岩及斜长辉石橄榄岩组成.Re-Os同位素分析样品包括非矿化斜长辉石橄榄岩、斑点状(浸染状)、陨铁状(网脉状)矿石及其选纯硫化物、块状硫化物.……

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简介：TheDachangtin-polymetallicdistrict,Guangxi,China,isoneofthelargesttinorefieldsintheworld.Bothcassiterite-sulfideandZn-CuskarnmineralizationarehostedintheMid-UpperDevoniancarbonate-richsedi-mentsadjacenttotheunderlyingCretaceousLongxianggaigranite（91-97Ma）.TheLamoZn-CudepositisatypicalskarndepositinthedistrictandoccursatthecontactzonebetweentheUpperDevonianlimestoneandthegranite.Theoremineralsmainlyconsistofsphalerite,arsenopyrite,pyrrhotite,galena,chalcopyrite,andminormolybdenite.However,theageofmineralizationandsourceofthemetalsarenotwellconstrained.Inthisstudy,weusethemolybdeniteRe-Osdatingmethodandin-situPbisotopesofsulfidesfromtheLamodepositforthefirsttimeinordertodirectlydeterminetheageofmineralizationandthetracingsourceofmetals.SixmolybdenitesamplesyieldedamoreaccurateRe-Osisochronageof90.04-1.1Ma（MSWD--0.72）,whichismuchyoungerthanthereportedgarnetSm-Ndisochronageof95±11MaandquartzfluidinclusionsRb-Srisochronageof99±6Ma.ThisageisalsointerpretedastheageofZn-Cuskarnminer-alizationintheDachangdistrict.Further,inthisstudywefoundthatin-situPbisotopesofsulfidesfromtheLamodepositandfeldsparsinthedistrict＇sbiotitegraniteandgraniticporphyrydikeshaveanarrowrangeandanoverlapofPbisotopiccompositions（206pb/204pb18.417-18.594,207pb/204pb=15.641-15.746,and208pb/204pb=38.791-39.073）,suggestingthatthemetalsweremainlysourcedfromCretaceousgraniticmagma.