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简介：1.Tcetonicandmagmaticactivizationproeesscs(tcetonicandthermalregenerationofancientbasc-mentordiwa)occurrcdinPhancrozoicanda1soil1Prccan1briantimc.Activizationrcgin1csbccamcap-parcntalrcadyinArchcantimcandthcirimportanccsignificantlyincrcascdduringLatcProtcrozoicpcri-odwhcnmanypartsofArchcancrustwcrc

简介：Forskarntypedeposits,therearetwokindsofskarns,skarnformedbyfiltrating-diffusingmetasomatismandveinskarnformedbyfilling.Theveinskarn,discussedthispaperandconsideredtobemagmaticgenesis,ischaracterizedby:(1)occurringasveinwithdistinctboundarieswithcountryrocks,yetjustthesameeveninmarbleeasytobereplaced;(2)composedofamineralassemblagesimi-lartothatofgranite,containingpegmatiteaswellascoarseskarnmineralpockets,andsometimestran-sitedwithdikerocks;(3)clearcrystallinefeatureofdeposition;(4)sideronintietexture;(5)showingvesicular,bean-likeandflowstructures;(6)verycommonliquidimmiscibility;(7)verticalzoningofgravitationaldifferentiationcausedbyvolatileconcentrationupwards;(8)associatedandtransitedwithiron-copperorebodiesofmagmaticgenesisandtungsten-bearingquartzveinsofsilicatemagmaticgene-sisrichinvolatile;(9)meltinclusions.Twooriginsofskammagma,originatedbyassimilationofsilicatemagmaatitsemplacem

简介：Chinaisamongthefewcountriesrichinpytophyllite.ItisinferioronlytoJapanandSouthKoreainprovedorerescrvesandranksthirdintheworldinperspectivereservesPyrophylliteoccurrencesinSupportcdbytheNaturalScienccFoundationofHunanProvinceandthcDirectorFoundationofChangshaInstituteofoeotectoniCS,ACademiaSinica.Chin

简介：<正>1IntroductionVirusesarethemostabundantbiologicalentitiesonEarth.Theycaninfluencethesuccessionofindividualmicrobialpopulations,biogeochemicalcyclesofC/Nand,ultimately,microbialcommunitystructurethroughkilling

简介：ThereareobviousdifferencesinthemineralassemblageandmetamorphicP-TconditionsbetweentheeclogitesfromthenorthernandsouthernpartsoftheeasternDabieMountains.ThosefromthenorthernpartofthemountainsaredevelopedinAlpineperidotiteandgneiss.Theyhaveamineralassemblageofgarnet+diopsidewithnoquartz,andwereformedattemperaturesof600℃-740℃.Thosefromthesouthernpartaredevelopedingneissandmarble.Theyconsistofgarnet+omphacite+lessquartzandweremetamorphosedattemperaturesintherangeof650°-800℃.Thesedifferencessuggestthattheformermaybeformedduringthemetamorphismofthedeepsubductedoceaniccrust,whereasthelattermaybegeneticallyrelatedtothesubductionofthecontinentalcrustinthisarea.

简介：ItisanacceptedfactthatthemainsolidphasesupportforpotassiumintheSichuanBasinispolyhalite[K2MgCa2(SO4)4·2H2O]ratherthansylvineis(KCl)(GongDXetal.,2015).Themineraltypes,occurrencecharacteristicsandmetasomatismofthepolyhalitebearingore-bedwereidentifiedandtheoriginofthepolyhalitewasdiscussed.ThepolyhalitesampleswereobtainedfromthecoreofZ12,locatedinDalongVillage,Guang'anCityofcentralSichuan.Thesamplingdepthswere2974m(s-1),3023m(s-2)and3106m(s-3).Themicrobeamanalysisofback-scatteringimageswascarriedoutusingaShimadzuEPMA-1720Serieselectronprobemicro-analyzer,supplementedbyaquantitativespectrumanalysisthatdeterminedthemineraltypes.

简介：TheNandan-Hechimetallogeneticbeltisthemostimportanttin-polymetallicproducingdistrictinChina,andisthelocationoftheDachangsuper-largetindeposit.Basedonthedetailedfieldinvestigationandisotopicdata,thestagesofmagmaticactivityintheNandan-Hechimetallogeneticbelthavebeenlinedoutinthispaper.Throughthestudyaboutthegeochemicalcharacteristicsofdifferentgranites,andbyusingω(Al2O3)-ω(SiO2),ω(TFeO)/[ω(TFeO)+ω(MgO)]-ω(SiO2),AFM,ACFandRb-Yb+Ta,Rb-Y+Nb,Ta-Yb,Nb-Ydiscriminationdiagramsincombinationwithregionalgeologicalsettinganalysis,theauthorscarriedoutanalysesaboutthestructuralenvironmentfortheformationofthegranites,anddiscussedthestructuralenvironmentanddynamicsettingforthelargescalemineralizationinthisarea.OurstudyindicatesthatthemajorityofthegranitesinNandan-HechimetallogeneticbeltbelongtothePOGtype,whilethelaterstagealaskitebelongstotheRRG+CEUGtype.Thegraniteswereformedatthestageofstructuraltransformationfrompostorogenicphasetointraplatesetting.Butthemajorstructuralenvironmentischaracterizedbysteadyregionalextension.Theformationageforthegranitescoincideswiththetimeforthistransformation,andthistranslationenvironmentisfavoredforlarge-scalemetallogenesis.

简介：Post-collisionalvolcanicrocksofMesozoicageoccurintheregionsadjacenttoGerze,partofthesouthernQiangtangTerraneofnorthernTibet,China.Geochronological,geochemical,andwholerockSr-Ndisotopicanalyseswereperformedonthevolcanicrockstobettercharacterizetheiremplacementageandmodelsfortheirorigin.Laserablation-inductivelycoupledplasma-massspectrometry(LA-ICP-MS)U-Pbzirconanalysesyieldedconsistentagesrangingfrom123.1±0.94Mato124.5±0.89Maforsixvolcanicrocksfromthestudyarea.Theintermediatevolcanicrocksbelongtothealkalineandsub-alkalinemagmaseriesintermsofK2O+Na2Ocontents(5.9%–9.0%),andtotheshoshoniticandcalc-alkalineseriesonthebasisoftheirhighK2Ocontents(1.4%–3.3%).TheGerzevolcanicrocksarecharacterizedbytheenrichmentoflightrareearthelements[(La/Yb)N=34.9–49.5]andlarge–ionlithophileelements(e.g.,Rb,Ba,Th,U,K,Pb,andSr),slightlynegativeEuanomalies(Eu/Eu*=0.19–0.24),andnegativeanomaliesinhighfieldstrengthelements(e.g.,Nb,Ta,HfandTi),relativetoprimitivemantle.Thesamplesshowslightlyelevated(87Sr/86Sr)ivaluesthatrangefrom0.7049to0.7057,andlowεNd(t)valuesfrom-0.89to-2.89.Theseresultssuggestthatthevolcanicrocksstudiedderivedfromacompositionallyheterogeneousmantlesourceandthattheirparentmagmaswerebasaltic.Themoremafic,parentalmagmastotheGerzevolcanicrockslikelyunderwentfractionalcrystallizationofclinopyroxene,hornblende,biotite,andpotassiumfeldspar,duringascent,withlittletonocrustalcontamination,priortotheireruption/emplacement.Whilethesevolcanicrocksexhibitgeochemicalsignaturestypicalofmagmasformedinadestructiveplate-marginsetting,itisplausiblethattheirmantlesourcemightalsohaveacquiredsuchcharacteristicsinanearlierepisodeofsubduction.