正文描述:《Itqiy A study of noble gases and oxygen isotopes including its terrestrial ageItqiy:包括地球年龄在内的稀有气体和氧同位素研究 与Zaklodzie比较》由会员上传分享,免费在线阅读,更多相关内容在学术论文-天天文库。
1、Meteoritics&PlanetaryScience37,823-833(2002)Availableonlineathttp://www.uark.edu/meteorItqiy:AstudyofnoblegasesandoxygenisotopesincludingitsterrestrialageandacomparisonwithZaklodzieANDREAPATZERI*,DOLORESH.HILLl,WILLIAMV.BOYNTONI,LUITGARDFRANKE2,LUDOLFSCHULTZ2A.J.TIMOTHYJULL3,LANNYR.McHARGUE3ANDIANA
2、.FRANCHI41LunarandPlanetaryLaboratory,UniversityofArizona,Tucson,Arizona85721,USA2Max-Planck-InstitutfurChemie,D-55020Mainz,Germany3NSF-ArizonaAcceleratorMassSpectrometerFacility,UniversityofArizona,Tucson,Arizona85721,USA4PlanetarySciencesResearchInstitute,OpenUniversity,WaltonHall,MiltonKeynes,MK
3、76AA,U.K.*Correspondenceauthor'semailaddress:apatzer@lpl.arizona.edu(Received2001December19;acceptedinrevisedform2002March4)Abstract-Wereportnoblegas,oxygenisotope,14CandlOBedataofItqiyaswellasnoblegas,14CandlOBeresultsforZaklodzie.Bothsampleshavebeenrecentlyclassifiedasanomalousenstatitemeteorites
4、andhavebeencomparedintermsoftheirmineralogyandchemicalcomposition.ThecompositionofenstatiteandkamaciteandtheoccurrenceofspecificsulfidephasesinItqiyindicateitformedundersimilarreducingconditionstothosepostulatedforenstatitechondrites.Thenewresultsnowseemtopointatadirectspatiallink.Thenoblegasrecord
5、ofItqiyexhibitsthepresenceofatrappedsubsolarcomponent,whichisdiagnosticforpetrologictypes4-6amongenstatitechondrites.Theconcentrationofradiogenic4HeisverylowinItqiyandindicatesarecentthermalevent.Its21Necosmic-rayexposureageis30.1±3.0Maandmatchesthemostcommonagerangeofenstatitechondrites(mostlyEL6c
6、hondrites)butnotthatofZaklodzie.Itqiy'sisotopiccompositionofoxygenisingoodagreementwiththatobservedinZaklodzieaswellasthosefoundinenstatitemeteoritessuggestinganoriginfromacommonoxygenpool.Thenoblegasresults,ontheotherhand,givereasontobelievethattheoriginandevolutionofItqiyandZaklodziearenotdirectl
7、yconnected.Itqiy'sterrestrialageof5800±500yearsshedscruciallightontheuncertaincircumstancesofitsrecoveryandprovesthatItqiyisnotamodemfall,whereasthe14CresultsfromZaklodziesuggestithitEarthonlyrecently.INTRO
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