第五章 矿物温度计与压力计.ppt
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第14卷第1期2007年1月地学前缘(中国地质大学(北京);北京大学)Earth Science Frontiers (Chin a University of Geosciences,Beijing;Peking University)Vol.14No.1Jan.2007收稿日期:2006-08-28;修回日期:2006-12-04基金项目:国家自然科学基金资助项目(40472045)作者简介:吴春明(1967)),男,博士,副教授,岩石学专业。
E -mail:w ucm@gu cas 1ac 1cn泥质变质岩系主要的矿物温度计与压力计吴春明, 肖玲玲, 倪善芹中国科学院研究生院地球科学学院,北京100049Wu Chunming , Xiao Lingling, Ni ShanqinCollege of Earth Sc ienc e,Gr adu ate Univ ersity of the Chinese Ac ade my of S cience s,Beij ing 100049,ChinaWu Chunming,Xiao Lingling,Ni Shanqin 1Main geothermometers and geobarometers in metapelites 1Earth Science Frontiers ,2007,14(1):144-150Abstract:T his paper briefly discusses the applicability,validity and er ro r so ur ce of the geo thermometer s and geo bar ometers applicable t o met apelites.T hro ug h co mpar ativ e studies,we have found that so me thermo ba -rometer s are valid and applicable,including the ga rnet -biotite and g arnet -musco vite g eothermo met ers,and the gar net -a luminosilicate -plag ioclase -quar tz (GA SP ),g arnet -biotite -plagioclase -quart z (GBPQ ),g arnet -musco -vite -plag io clase -qua rtz (G M PQ ),gar net -biotite -muscovite -aluminosilicate -quartz (G BM AQ )and g arnet -rutile -ilmenit e -plagioclase -quartz (GRIP S)g eo ba rometer s.T he present tw o -mica and muscov ite -plag ioclase g eother -mo meters are not v alid and cannot be applied.Still some thermo meters and baro met er s need to be st udied in or der to ev aluate t heir validity and a pplicability ,including the gar net -co rdierite g eo thermometer and the g arnet -cordier ite -alumino silicate -quar tz (G CAQ )and ga rnet -rutile -aluminosilicate -ilmenite -quartz (GRA IL )g eo ba -rometer s.Key words:metapelites;g eothermo metry ;g eobarometr y摘 要:简要介绍泥质变质岩中常用的温度计和压力计,对其可适用性、适用范围、质量优劣等进行了评述。
1000 0569/2021/037(01) 0035 51ActaPetrologicaSinica 岩石学报doi:10 18654/1000 0569/2021 01 03活度在矿物温度计与压力计中的作用———以GB温度计与GASP压力计为例吴春明 刘嘉惠WUChunMingandLIUJiaHui中国科学院大学地球与行星科学学院,北京 100049CollegeofEarthandPlanetarySciences,UniversityofChineseAcademyofSciences,Beijing100049,China2020 09 10收稿,2020 12 25改回WuCMandLiuJH 2021 Effectofactivityongeothermobarometry:CasestudyoftheGBgeothermometerandGASPgeobarometer ActaPetrologicaSinica,37(1):35-51,doi:10 18654/1000 0569/2021 01 03Abstract Concentrationistherealphysicalpropertyofasolution,whereasactivityisthe“effectiveconcentration”ofnon idealsolutionsincludingsolidsolutions Takenthegarnet biotite(GB)geothermometerandgarnet Al2SiO5 plagioclase quartz(GASP)geobarometerasexamples,theeffectofactivityongeothermobarometryhasbeendiscussedinthiscontribution Usingexperimentaldataandadoptingdifferentactivitymodelsofgarnetandbiotite,theyieldeddifferentversionsofGBgeothermometerscanrebuildtheexperimentaltemperaturestodifferentprecision,andfurthermore,theyallcandiscernthegradualtemperaturechangeofdifferentmetamorphiczonesofeitherprogradesequences,orinvertedmetamorphicterranesorthermalcontactaureoles But,largersystematicerrorscanbeobtainedwhentakingbothgarnetandbiotiteasidealsolidsolutions,andthecalibratedGBgeothermometeralwaysunderestimatetemperatureconditions Meanwhile,theGASPgeobarometeralwaysoverestimatesmetamorphicpressureconditions,whentakingbothgarnetandplagioclaseasidealsolidsolutions Whenadoptingthenon idealactivitymodelsofbothgarnetandplagioclase,thederiveddifferentGASPgeobarometerscansuccessfullyplottheAl2SiO5bearingmetapeliteintothecorrectstabilityfieldofAl2SiO5phases Uptillnow,universalactivitymodelsofmineralssuitabletodifferentrocktypesaswellaswideP Tconditionsareextremelyscarce Inaddition,P Tresultsyieldedfromgeothermobarometerscalibratedsolelybysolidphases,cantruthfullyreflectthegeologicP Trealities,albeitfluidormeltphasesarenotconsidered Keywords Activity;Applicability;Geobarometer;Geothermometer摘 要 浓度是溶液中客观存在的物理性质,活度则指非理想溶液(包括非理想固溶体)中组分的“有效浓度”。