高温高压下含水矿物脱水对斜长岩纵波速度的影响EFFECTS OF DEHYDRATION ON THE P-WAVE VELOCITY OF ANORTHOSITE AT HIGH PRESSURE AND HIGH TEMPERATURE
白利平,杜建国,刘巍,张文兰
摘要(Abstract)：
在1GPa、室温至880°C条件下对斜长岩的纵波速度进行了测量,并对实验产物进行了鉴定分析,讨论了含水矿物脱水对岩石纵波速度的影响。实验结果表明,在680°C左右,由于斜长岩中的含水矿物绢云母和黝帘石开始脱水,矿物脱水产生的流体及其所引起岩石结构的变化可使岩石纵波速度降低10%左右。这意味着通过矿物脱水这一机制可以形成壳内低速层。
关键词(KeyWords)： 斜长岩;纵波速度;矿物脱水;高温高压
基金项目(Foundation): 国家自然科学基金资助项目(10032040,49874013);; 地震科学基金资助项目(101119))
作者(Author): 白利平,杜建国,刘巍,张文兰
Email:
DOI:
参考文献(References)：
- [1] PoppT,KernH.Thermaldehydrationreactionscharacterisedbycombinedmeasurementsofelectricalconductivityandelas-ticwavevelocities[J].EarthPlanet.Sci.Lett.,1993,120:43—57.
- [2] KernH,TubiaJM.PressureandtemperaturedependenceofP-andS-wavevelocities,seismicanisotroyanddensityofshearedrocksfromtheAlpujatamassif(Rondaperidotites,SouthernSpain[J].EarthPlanet.Sci.Lett.,1993,119:191-205.
- [3] ItoK.EffectsofH2Oonelasticwavevelocitiesinultrabasicrocksat900°Cunder1GPa[J].Phys.EarthPlanet.Inter.,1990,61:260-268.
- [4] 谢鸿森.地球深部物质科学导论[M].北京:科学出版社,1997.1-53.
- [5] SchmelingH.PartialmeltbelowIceland:Acombinedinter-pretationofseismicandconductivitydata[J].J.Geophys.Res.,1985,90:10105-10116.
- [6] MatsushimaS.Partialmeltingofrocksobservedbythesoundvelocitymethodandthepossibilityofaquasi-drylowvelocityzoneintheuppermantle[J].Phys.EarthPlanet.Inter.,1989,55:306—312.
- [7] SatoH,SacksIS,MurseT,etal.Qp-meltingtemperaturere-lationinperidotiteathighpressureandtemperature:Attenua-tionmechanismandimplicationsforthemechanicalpropertiesoftheuppermantle[J].JGR,1989,94(B8):10647—10661.
- [8] TatsumiY,ItoK,GotoA.Elasticwavevelocitiesinisochme-calgranuliteandamphibolite:Originofalow-velocitylayerattheslab/mantlewedgeinterface[J].Geophys.Res.Lett.,1994,21(1):17—20.
- [9] ItoK,TatsumiY.MeasurementofelasticwavevelocitiesingranuliteandamphibolitehavingidenticalH2O-freebulkcom-positionsupto850°Cat1GPa[J].EarthPlanet.Sci.Lett.,1995,133:255—264.
- [10]GriggsDJ.Hydrolyticsweakingofquartz,othersilicates[J].Geophys.J.R.Astr.Soc.,1967,14:19—31.
- [11]LebedevEB,KernH.Theeffectofhydrationreactionsonwavevelocitiesinbasalts[J].Tectonophys.,1993,308:331—340.
- [12]MitchellBJ,LandismanM.Electricalandseismicpropertiesoftheearth'scrustinthesouthwesterngreatplainsoftheUSA[J].Geophysics,1971,36:363—381.
- [13]陈墨香.中国地壳上地幔地球物理探测成果[A].见:国家地震局《深部物探成果》编写组.深部物探成果[M].北京:地震出版社,1986.
- [14]PollackMN,ChapmanDS.Ontheregionalvariationofheatflow,geothermsandthethicknessofthelithosphere[J].Tectonophysics,1977,38:279—296.