摘要
TheTianbaoshandeposit,locatedinthesouthwesternpartoftheYangtzeBlock,isarepresentativePb-ZndepositintheSichuan-Yunnan-GuizhouPb-Znmetallogenicprovince.ThePb-ZnorebodiesarehostedintheupperSinianDengyingFormationdolostone.Thepredominantmineralsaresphalerite,galena,pyrite,chalcopyrite,quartz,andcalcitewithminorarsenopyrite,fahlore,anddolomite.ThedepositischaracterizedbyrelativelystrongCumineralization.However,therelationshipbetweenPb-ZnandCumineralizationisunknown.Weanalyzedthemineralogyandcompositionoffahlore,chalcopyrite,arsenopyrite,sphalerite,andgalenausingscanningelectronmicroscopy-energydispersivespectroscopy,withtheaimofprovidingnewevidenceforthegenesisofthePb-Zn-(Cu)ore.TheresultsshowthattheCuoreinthedepositisdominatedbychalcopyriteandfahlore,bothofwhichformedbeforeorduringthePb-Znore-formingstage.ThefahloreshoweddramaticcompositionalvariationandwascharacterizedbynegativecorrelationsbetweenAgandCu,andbetweenAsandSb,suggestingsubstitutionofAgforCu,andthatAsandSbsubstituteinthesamesiteinthefahlorelattice.Basedonbackscatteredelectronimagesandcomposition,thefahlorewasdividedintotwotypes.TypeIfahlorecrystallizedearlyandischaracterizedbyenrichmentofCuanddepletioninAgandSb.TypeⅡfahloreformedafterTypeI,andisrichinAgandpoorinCuandAs.Moreover,galenaandfahlorearethehostmineralsofAg.ThevariationofvalencestatewithAshostmineral--fromfahloretoarsenopyrite-indicatesthemetallogenicenvironmentchangedfromrelativelyoxidizingtoreducingwithahighpH.InthelightofGibbsenergiesofreciprocalreactionsandisothermsforcationexchange,thecompositionofthefahloreimpliesitsore-formingtemperaturewaslowerthan220℃,correspondingwithtypicalMississippiValley-type(MVT)deposits.Basedonthegeologiccharacterandgeochemicaldataofthisdeposit,wesuggestthattheTianbaoshandepositbelongstotheMV
出版日期
2018年06月16日（中国期刊网平台首次上网日期，不代表论文的发表时间）
