简介：0IntroductionTheJapaneseIslandsconsistoffivevolcanicarcs(Fig.1).TheNorth-EastandSouthWestJapanarcstogetherformtheHonshuarc,towhichtheKurilearcjoinsatHokkaido,whereastheIzu-MarianaarcjoinsatIzu-FossaMagna,andtheRyukyuarcjoinsatKyushu.Theseregionswherevolcanicarcsconverge,aretermed'islandarcjunctions'.

简介：对中间的熔岩的起源有许多最近的兴趣，几个假设是：1)在浸透水的条件下面的披风的直接融化，2)改变的外壳的部分融化，3)父母岩浆的部分结晶化，并且4)岩浆与dacitic/rhyolitic岩浆混合mafic岩浆。暴烈摇系列从东方手盆从玄武岩的安山岩到dacite(从53.8～63.0wt.%的SiO2范围)被检测为主修并且跟踪元素作文理解他们的起源。低H2O内容，2和Yb-SiO2,氧同位素数据和在斜长石斑晶的摆动的zoning的踪迹元素集中的模糊变化排除的La-SiO的积极关联硅的熔岩从含水的披风的直接融化导致的模型，改变的海洋的外壳或斑粝岩的部分融化，并且分别地混合的岩浆。除以外，geochemical数据完全摇并且融化包括显示部分结晶化在产生中介起一个主导的作用有subduction特征的熔岩。

简介：WudalianchivolcanicrocksarethemosttypicalCenozoicpotassicvolcanicrocksineastenChina.Compositionalcomparisonsbetweenwholerocksandglassesofvariousoccurrencesindicatethatthemagmatendstobecomerichinsilicaandalkalisasaresultofcrystaldifferentiationinthecourseofevolu-tion.TheyareuniqueinisotopiccompositionwithmoreradiogenicSrbutlessradiogenicPb.^87Sr/^86Srishigherand^143Nd/^144Ndislowerthantheundifferentiatedglobalvalues.Incomparisontocontinentalpot-ashvolcanicrocks,Pbisotopesareapparentlylower.Thesevariousthreadsofevidenceindicatethattherockswerederivedfromaprimaryenrichedmantlewhichhadnotbeensubjectedtoreworkingandshowsnosignofincorporationofcrustalmaterial.ThecorrelationbetweenPbandSrsuggeststheregionalheterogeneityintheuppermantleintermsofchemicalcomposition.

简介：ThegeochemistryofthebasicvolcanicrocksatthesouthmarginoftheQinlingorogenicbelt(SMQOB)suggeststhattheywereformedinanintraplatetectonicsetting.TheREEdistributionpatternsshowtheserocksarestronglyenrichedinLREEwithhigh∑REE,andtheirtraceelementsgeochemistryissimilartothatofcontimentalfloodbasalt.AlltheaboveevidencesuggeststhattheCaledonianbasicvolcanicrocksintheSMQOBweretholeiiticbasaltsformedinanintraplatespreading-initialrifttectonicsetting.Thecharacteristicsofregionalgeologyandgeochemistryindicatethattherewasanintraplatespreading-rifttectonicsettingbetweentheSouthQinglingblockandtheYangtzeblockintheCaledonianepoch.ThedynamicspreadinginthisdistrictbeganintheEarlyCaledonianandthentheintraplatespreadinginitialriftswereformedintheLateCaledonian.AsaresultofspreadingoftheTethysandgeodynamicprocessesindeepmantle,theMianlue-HuashanoceanicbasinwasformedbetweentheQinlingblockandtheYangtzeblockinDevonian,andtheQinlingmicroplatewasseparatedfromthenorthernpartoftheYangtzeplate.

简介：Tephrafalloutisanimportanttypeofhazardcausedbyexplosivevolcaniceruption,andnumericalsimulationhasbecomeafastandeffectiveapproachtoassessthedispersionanddepositionoftephrafallout.Accordingtotheimproved2DdiffusionmodelofSuzuki(1983),weeditedatephradiffusionprogramthatcanrunintheWindowssystem.Basedonpreviousdata,wesimulatedthediffusionscopeoftheJinlongdingzivolcaniceruption,whichisthelatesteruptionintheLonggangvolcaniccluster.Thesimulatedresultsareingoodagreementwiththeresultsfrommeasurementinsitu,indicatingthatthemodelisreliableandtheparametersusedinthemodelaresuitable.Byusingwindprofilesoftenyears,7,021simulationsunderdifferentwindprofileswerecarriedout,andthenprobabilistichazardmapsoftephrafalloutwereconstructedfortephrathicknessthresholds,1cmand0.5cm.Thisstudycanprovideanimportantscientificbasisforvolcanichazardanalysis,riskmitigationplansandcountermeasuresintheLonggangvolcanicarea.

简介：Theprocess-faciestypesoftheDevonianvolcanicsedimentarysuccessionsinnorthernXinjiangincludeexplosivefacies,effusivefacies,pyroclastic-calcareous-terrigenoustempestitefacies,andcoarse~-,medium~-andfine-grainedpyroclasticturbiditefacies,volcaniceruptiontsunamitefacies,syndepositionalandsoft-deformedseismitefacies,sandyandsilt-muddycontouritefacies.Thispaperpresentstheircharacteristicsanddiagnosticindicators,anddiscussesthetemporalandspatialstructuresofboththeprocess-faciesandtheenvironment-faciesoftheZhifangsection,eastJunggar,andtheMountSarburtisection,westJunggar,andtheirrelationtoplatetectonism.Theauthorholdsthatthefaciesanalysisdominatedbyprocess-faciesisthefaciesanalysis’nucleusinanorogenicbeltandactivecontinentalmargin.

简介：Themajorelements,traceelements,K-ArageandSr-Nd-PbisotopicsystemsoftheCenozoicvolcanicrocksinDaheishanIslandandCishan,Penglai,ShandongProvincearemeasured.Thevolcanicrocks(olivine-nepheliniteandnepheline-basanite)inDaheishanIslanderuptedperiodicallyinanintervalof0.32Ma,from8.72Ma,8.39Ma,8.08Mato7.73Ma.ThevolcanicrocksareallrichinlightREEs.TheyaresimilartotheOIB-typealkalibasaltinthetraceelementsnormalizedmodelbyprimordialmantle:richinhighfieldelementssuchasNbandTa,andimcompatibleelementssuchasCs,Rb,Ba,Th,U.ThevolcanicrocksshowadepletionofKandRbelements.Itissuggestedbythetraceelementsthattheolivine-nepheliniteinDaheishanIslandisoriginatedfromdeepresourcesunderthecontinentalmantle.εNd(0)valuesofthevolcanicrocksinDaheishanIslandandCisbanare5.31～8.51and7.33respectively,suggestingthatthevolcanicrocksarefromthedepletedmantleresources,whichhavehigherSm/NdratiosthantheCHUR.143Nd/144NdratiosofDaheishanIslandolivine-nepheliniteandCishanalkalibasaltsare0.512910～0.513074and0.513014respectively.The87Sr/86SrofDaheishanIslandvolcanicrocksarelowerthanthatofCishan,0.703427～0.703482and0.703895respectively.TheDaheishanIslandolivinenephelinitehasthePbisotopicvaluesasfollows:206Pb/204pb=18.0289～17.9728,207Pb/204pb=15.4358～15.4022and208Pb/204Pb=38.0876～37.9975,lowerthanthoseofCishanbasanite.TheCishanbasanitehas206Pb/204pb=18.2401,207Pb/204Pb=15.5645and208Pb/204pb=38.535.Theauthorssuggestthattheolivine-nepheliniteinDaheishanIslandissimilartotheE-typeMORBorHawaiiOIB,andthealkalibasaltsinCishansimilartotheKerguelenOIB.ThedominantmantlecomponentsofDM+PREMAandperhapsDM(Dupaltype)arethedominantmantlecomponentsforvolcanicrocksinDaheishanIslandandCishan.ThePREMAcomponentplaysanimportantrole.

简介：这篇论文重新描述奥陶纪前(Pt_3)的特征在从方面ofpetrographic特征，岩石集合，石油化学，REE，痕量元素，铅同位素和大地构造的背景的云南省的Huimin-Manlai区域的变形火山岩。变形火山岩维持blasto-intergranularandblasto-andesitic质地；火山岩被basalt-andesite-daciteassemblage描绘；火山岩是在化学成分的basic-intermediate-intermediate-acid，属于半碱的岩石，与计算碱的系列并且拉斑玄武岩系列共存，并且他们被低TiO_2内容描绘；他们的REE分发模式theLREE丰富是使权利倾向的类型；火山岩在大阳离子元素被充实并且通常在Th充实并且部分在Ti，Cr和P弄空，属于从他们的Pb同位素组成看了的Gondwana类型；石油化学地，数据点主要在岛弧火山岩的地以内掉落。所有这些特征在学习的区域为原来的Tethysan岛弧火山岩的存在提供了新证据。

简介：Geochemical特征上面二叠(P_2)大陆人边缘的弧火山岩被描述，它最近在XiaodingxiandZangli的区域附近基于Yunxian-Lincang花岗石的东方方面以岩石集合，石油化学，REE，痕量元素，Pb同位素，大地构造的环境等等。火山岩集合被basalt-andesite-dacite统治，与次要的粗面岩andecite-trachyte；火山岩系列被计算碱的系列支配，与次要的tholleiite系列和碱的系列岩石；火山岩被高Al_2O_3和低TiO_2描绘，与显示出极其强壮的极性的K_2Ocontents；REE分发模式被LREEenrichment和使权利倾向的类型描绘；痕量元素和大阳离子元素高度被充实，Ti和Cr被弄空，并且P和Nb部分被弄空；Pb作文具有Gondwanatype；石油化学的点主要在岛弧火山岩的地以内掉落，有数据的设计的矛盾大陆人把边缘的火山岩指向南方Lancangjiang带和北方Lancangjiang带的南部的片断。这个大陆人边缘的弧火山岩带和在Changning-Menglian带的海洋山脉和海洋岛火山岩andophiolites，组成海洋山脉火山岩，在对分布式的ophiolite-arcrock-magmatic岩石带，显示Lancangjiang海洋的外壳向东代替ducted。这结果在在Lancangjiang带抑制thepaleo-Tethys的进化是很重要的。

简介：TheregularvariationsinmagmaticactivitiesalongtheNorthwestPacificplatehavebeenlittlestudiedinspiteoftheirimportance.Inthiscontribution,systematicanalyseswereconductedontholeiiticbasaltsfromthreeOceanDrillingProgramsites（Sites304,1149,and801）,includingthepetrographicfeatures,majorandtraceelements,Ndisotopiccompositions,andmineralstructureandcompositionsofwholerocks.VolcanicrocksfromSites304,1149,and801belongtotholeiitesandexhibitdepletedlightrareearthelements（LREE）,largeionlithophileelementalcontents（LILE）,andrelativelydepletedNdisotopicratios（143Nd/144Nd=0.513139-0.513211）,similartothoseofnormalmid-oceanridgebasalts（N-MORB）.Comprehensivedataonmineralcompositions,whole-rockgeochemistry,andgeochronologydemonstratethataregularvariationtrendexistsinthenorth-southdirectionalongtheNorthwestPacificplate.The143Nd/144Ndvalues（0.513139-0.513211）andtrace-elementratiosforwholerocks（Sm/Th=15.35-30.00;Zr/Hf=28.53-35.76;Zr/Y=2.58-3.67;Th/La=0.04-0.06;Th/Y=0.33-0.70）,aswellasthetrace-elementratios（Zr/Hf,La/Yb,Ti/Zr）ofclinopyroxenesfromSites1149and801tholeiitesshowlargervariationscomparedtothosefromSite304tholeiites（143Nd/144Nd=0.513185-0.513195;Sm/Th=18.19-20.58;Zr/Hf=31.07-33.26;Zr/Y=2.62-3.03;Th/La=0.05-0.06;Th/Y=0.48-0.57）.MineralzoningtextureswereobviousintholeiitesfromSites1149and801butwererarelyobservedinSite304.Theseregularfeatureswerelikelyattributedtothedifferencesintheheterogeneityofthemagmasource,theprocessofmagmatieevolution,theplate-spreadingrate,andtheeffectiveandineffectivemixing.

简介：UltrabasicrocksintheMianxian-LueyangophioliticmelangezoneincludeharzburgiteanddunitewhichexhibitLREEdepletionwithremarkablepositiveEuanomaly.ThediabasedikeswarmshowsLREEenrichmentbutslightlynegativeEuanomaly.MetamorphosedvolcanicrockscanbedividedintotwogroupsintermsoftheirREEgeochemistryandtraceelementratiosofTi/V,Th/Ta,Th/YbandTa/Yb.OneisthsMORB-typebasaltwithLREEdepletion,representingthefragmentsofoceaniccrustandimplyinganassociationoftheMORB-typeophioliteandanancientoceanbasinbetweentheQinlingandYangtzeplatesduringtheMiddlePaleozoic-EarlyMesozoicera.Theotercomprisestheisland-arcvolcanicrocksincludingtholeiiticbasaltandalargeamountofcalc-alkalineintermediate-acicvolcanicrock,whichcouldnotbethecomponentoftheancientoceaniccrustbuttheresultofmagmatismatthecontinentalmargin.ThisindicatesthattheMianxian-Lueyanglimitedoceanbasinhadundergoneawholeprocessofdevelopment,evolutionandvanishingfromDevonian-CretaceoustoPermian.AndtheQinlingareahadbeconeanindependentlithosphericmicroplate,onthesouthernsideofwhichtherewereexhibitedthetectoniccharacteristicsofactivecontinentalmarginsduringtheLatePaleozoic-EarlyMesozoic.Thatistosay.theQinlingcannotbesimplyconsideredasaresultofcollisionbetweentheYangtzeandNorthChinaplates.

简介：

简介：ObjectiveThepotassicandultrapotassicrocksrelatingtotheIndia-EurasiacollisionandcontinualplateconvergencearewidelydistributedintheLhasaterrane.TheserocksareveryimportanttounderstandthedeepprocessesoftheIndia-EurasiacollisionandtheupliftandevolutionoftheTibetanPlateau.Althoughhigh-potassicvolcanicrocksarealsoexposedinthewesternLhasaterrane,theirformation

简介：

简介：最近，在Yaoyingtai的暴烈的煤气的水库()并且Daerhan()在Changling的构造的带()东南的Songliao的指责的消沉()盆被发现了。基于作文和同位素的价值，天然气被甲烷，C2+的低内容，和C1/C15的高内容超过0.95描绘。另外，天然气包含从20%～40%与内容包括二氧化碳的nonhydrocarbons和N2的次要的数量。与同位素的价值结合了，天然气被腐殖的kerogen和导出煤的类型产生，但是在Daerhan，天然气被油类型气体可能混合。从在暴烈的岩石中的岩性学和液体包括的测量，沥青，液体烃，和煤气的烃包括是在场的。通过在暴烈的水库的单个煤气的包括的分析，二氧化碳的内容是低的，因此水库的二氧化碳和烃气体没同时被积累。另外，在水库的沥青的次要的数量被通过biomarkers的描述从Yingcheng(842557CE)形成mudstones采购的原油的热进化形成。homogenization温度的分发与煤气的充满的舞台介绍二座山峰，有充满舞台的液体烃的山峰，和其它。在Daerhan构造的带，然而，第二座山峰是煤气的，二氧化碳混合可能充满时期。与盐水包括，油和煤气的充满时期的homogenization温度结合了从Qingshankou()形成到Nenjiang()在研究区域的形成。在收费时期期间，无机的二氧化碳的次要的数量从Sifangtai的结束充满了进陷井，而是很多的无机的二氧化碳()到Eogene，时期与结构的运动有关。

简介：

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.