Abstract:

ThebaritedepositsformedintheearlyCambrianinXinhuangandTianzhuarethelargestbaritedepositintheworldandare representativeintheglobalscope.Thisstudycarriedouttherareearthelementsandsulfurisotopeanalysesofthesebaritedeposits.All thesample'sV/CrandU/ThvaluesandtheCenegativeanomalyimpliedthatthedepositswereformedinanaerobicandreduction environment.TherareearthelementsofbaritehaveobviouslyEuelementpositiveanomaly,indicatingthattheore-formingprocesswas stronglyaffectedbytheseafloorhydrothemalfluidandthesourceofthebariumismainlyfromtheseafloorhydrothemalmaterial;The sulfurisotopecompositionofBaSO4mainlyrangedfrom+40‰to+45‰,enrichedin34SandthesulfurisotopeofBaSO4ischaracterized bytowerstyledistribution,whichindicatesthatthesourceofsulfurisofsingle-sourceandfromtheseawatersulfate.Theδ34Sofpyrite islowerthantheδ34Softhecontemporaryseawater,indicatingthatbiologicalbacteriaplayedanimportantroleinthesulfatereduction intheseawaterandimplythatthebaritedepositformedinanenvironmentwherethereislimitedseawaterexchange.Basedontheaboveanalysis,thebaritedepositwasformedinasemiclosed-closedlagoonalandanaerobicenvironmentwheretherearefrequent seafloorhydrothermalactivities.

Key words: :baritedeposits;traceelements;rareearthelements;sulfurisotope;Xinhuang;Tianzhu