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41 个结果
  • 简介:TheYinyanporphyrytindepositisablinddepositassociatedwithasmallgraniteporphyrystock.ThepetrologyandgeochemistryoftheYinyangraniteporphyrysuggestthatitisgeneticallyofthetransfor-mationtype,emplacedatthelatestageoffractionalcrystallizationwithinahigh-levelmagmachamber.Ore-formingfluidsarederivedpredominantlyfromthegraniticmagmaandtheyinteractwiththewallrocksintenselywhenfindingtheirwayupwardsthroughthegraniteporphyry.Fromthelowerpartoftheporphyryupwardsthefollowingalterationzonescanbedistinguished(a)slightlyalteredgraniteporphyry(withweakpotashfeldspathization),(b)protolithionite-quartzgreisenizationzone,(c)to-paz-quartzgreisenizationzone,(d)senicite-quartzsericitizationzone,and(e)silicificationzone(quartzcoreatthesurface).Tinmineralizationisrelatedtogreisenization,especiallytotopaz-quartzgreisenization.Rockandore-formingtemperaturesandoxygenfugacitiesareestimated,respectively.TherearesignificantdifferencesinmanyaspectsbetweentheYinyanporphyrytindepositandvolcan-ic-subvolcanicporphyrytindeposits.

  • 标签: 斑岩 锡矿床 地质构造 地球化学 广东
  • 简介:eRakaophioliteislocatedinthemiddlesectionoftheplatesuturezoneintheYarlungZangboregion,Tibet,Itissuggestedthatthegenesisoftheophioliteissimilartothatofnon-typicMORBinamarginaloceanbasinthroughfieldgeologicalinvestigation,lithogeochemicalanalysisandsyntheticalcomparison.ItisconcludedthattheophioliteinthisregionmayberelicsofthesubductedoceaniclithosphereintheNeo-Tehthysperiod.

  • 标签: 蛇绿岩 新特提斯海 海洋边缘盆地 岩石成因 西藏 地质构造
  • 简介:ThelateMesozoictwogianteventsthathavesynchronouslyoccurredinthePacificandperipheryarethetectono-magmaticactivitiesoftheCircum-PacificmobilebeltandtheDarwinRise.TheirdynamicsanalysisindicatesthatthegeodynamicsresponsibleforPacificgenesishasbeendrivenbythegravityinstabilitybetweenaPacific-widesuperplumeheadanditslithosphericoverburdenundertheinfluenceofeastwardasthenosphericflowbytheEarthspin.TheworldwideactivationofmaficmagmatismwasinitiatedinthePaleozoicandclimaxedaroundtheJurassic.TheseparatednotworldwidedistributionofthemagmatismontheEarthsuggeststheinhomogeneousreheatingofuppermantle,asrepresentedbythePacific-widesuperplumehead.ThePhanerozoicreheatingthusputforwardtheEarthhistoryintoanewgeotectonicstage,i.e.,thediwastage.

  • 标签: INHOMOGENEOUS REHEATING upper mantle PACIFIC GENESIS
  • 简介:TheHongshijinggolddeposit,whichoccursintheMiddleandLateCarboniferousvolcanicandpyroclasticrocks,isofthebrittle-ductileshearzonetypecontrolledbyariftbelt.TheHongshijinggolddepositisonecontrolledbyabrittleshearzonelocatedintheLatePaleo-zoicriftzone.Thealtered-rocktypeandquartztypeorebodiesarecontainedinthegold-bearingformation,whichconsistsofbasaltandtuffaceoussandstone.Themajormineralizingstageisat267-261Maandreiterationmineralizingstageat220-209Ma.Theoremineralsincludepy-rite,magnetite,copper,bornite,ferrohydrite,nativegold,andtheganguemineralsincludequartz,sercite,calcite,Fe-dolomite,leucoxene,anorthose,biotite,baria,cajuelite,andagustite.Thewallrockalterationassociatedwithgoldmineralizationcomprisessilicification,carbonization,pyritization,sericitizationandchloritization.Thecontentsofgoldare2.4×10-9inthegold-bearingformation,5.7×10-9inthetuffaceoussandstoneand1.4-1.5×109inthebasalt.AuisassociatedwithTe,Se,Ni,Cu.Au=74.331×Te+0.0335×Ni-0.0211×Cu-2.650.Geochemicalinvestigationsrevealedthatthemineralizingmaterialscamefromthebasaltandtuffaceoussandstoneinthegold-bearingformation.Undertheactionofductilebrittleshearstructure,thegold-bearingformationwasmetamorphosedandaltered,andtheore-formingmaterialsactivated,migratedandmineralized.Themineralizingfluidshowsthreemineralizingstages,withthecharacteristicsofmiddletolowtemperature(381-115℃)andmiddletolowmassfractionsofNaCl(2.18%-16.77%).ThefluidisoftheCa2+-Mg2+-Na+-Cl-typeandH2O-NaClsystem.Accordingtothedatafromhydrogenandoxygenisotopiccomposition(δD=-114.6‰--68.8‰,δ18OH2O=-2.47‰-5.91‰),theconclusioncanbedrawnthatthemineralizingfluidoftheHongshijinggolddepositwasakindofmixedhydrothermalsolutioncomposedmainlyofmeteoricwater,magmaticwaterandformationwaterinbas

  • 标签: 地质学 地球化学 起源 金矿床 成因 新疆
  • 简介:Fluidinclusionsinmineralsfilledinporesofreservoirrockscanbeusedasagoodindicatorofporegenesisanddevelopmentsoastoshedlightonoilgeneration,migrationandaccumulation.TherelationshipbetweenporeevolutionandoilgenerationhasbeenestablishedbasedonfluidinclusionstudiesontheLowerOrdoviciancarbonatereservoirstrataintheOrdosBaisn,NorthwestChina.Sevenstagesofporositydevelopmentcanberecogmized.i.e.,thepenecontemporaneous,theearlyandmiddle-latediagenetic,thesupergene,theearly,middleandlatere-buryingstages.Thedissolutionporesanfissuresformedinthesupergeneandmiddle-latereburyingstageandthestructuralfracturesformedinthelatere-buryingstageconstitutethemajortrapsofoilandgas.ThemajorphaseofoilmigrationandaccumulationtookplacebetweenLateJurassicandCretaceous,Correspondingtothemiddleandlatere-buryingstages.ThegenerationandaccumulationofoilcanbecloselyrelatedtoYenshaniantectonics.

  • 标签: 流体包裹体 碳酸盐 多孔性 地球化学 沉积物
  • 简介:ONENVIRONMENTALCONDITIONSOFTHEGENESISOFTORNADOINTHEZHUJIANGRIVERDELTAINSPRING¥WangPeilin王沛霖(DepartmentofAtmosphericSciences,Z...

  • 标签: Zhujiang RIVER DELTA SPRING TORNADO ENVIRONMENTAL
  • 简介:Jianglang山位于华南褶层系统,Jiangshan-Shaoxing深破裂地区和Baoan-Xiakou-Zhangcun破裂地区的过渡地区。形成Xiakou盆被土佬归因于拉开差错消沉

  • 标签: 地理学 地形学 发展 理论
  • 简介:Thesuper-largePb-ZndepositatFankouisverycomplexinmetallogenicmechanism.Syngeneticbrinesedimentation,hotsubmarinespringeruption-accumulation,syngeneticsedimentation-vadosebrinereplacementhadbeensupposedasthegeneticmodelsbefore.Underthesemodels,syngeneticmineralizationshouldbedominantinoreformation.However,aseriesofgeologicalandgeochemicalpropertiesinvestigatedbyauthorsofthispaperarecontrarytothesemodels.Therefore,theauthorsheresuggestthatthisdepositisatypicalpolygeneticcompoundoredepositwhichsharethepropertiesofmultistagesofgeotectonicevolution,multifactorsofmineralizationcontrol,multisystemofmaterialderivationofmineralization,multimodesofmineralizationandmultitypesofgenesis.

  • 标签: GENESIS ORE DEPOSIT the Fankou ORE
  • 简介:我们检验了为锰小瘤和外壳在收集的功课期间从中央印度洋盆(CIOB)恢复的超过五十使硬化的沉积。样品与palagonite一起或在锰小瘤的原子核以内作为铁锰合金氧化物在上或在改变的海洋的暗岩的底层上是在场的或在改变的海洋的暗岩的底层上的平板发生。矿物学上和作文联盟者,样品显示出phillipsite,palagonite和montmorillonite的混合物。我们建议火山发生在CIOB的遗传因子的先锋受到在低温度条件的影响下面改变改变的度,导致zeolitic泥土石头的形成。CIOB样品有类似到在世界海洋从各种各样的地点报导的那些。

  • 标签: 海解作用 沸石 自生作用 印度洋
  • 简介:TheoccurrenceandgeologicalgenesisofpyritesinLatePaleozoiccolasofNorthchinahavebeensystematicallystudiedintermsofcoalpetrology,coalchemistry,elementalgeochemistryandsulfurisotopegeochemistry.Theresultssuggestthateighttypesofpyrite,i.e.,framboidal,automorphicgraular,oolitic,massive,homogeneousspherical,allotriomorphic,nodular,joint-andfisure-fillingpyrintescanbesubdividedunderthemicroscope,Fourgenerationsofpyritearealsoreconizedaccordingtotheshape,size,coexistingassemblage,spacialdistributionrelationshipwithmacerals,thecontentsofsulfurandiron.atomicS/Feratiosandassociatedelementsinpryites.SulfurinLatePalozoiccolasofNorthChinaisofdiversesourceasevidencedbysulfurisotopevariationsinthepyrites.Theδ34Svaluesofpyritegeneratedattheearlystagetedtobenegative,andatthelatestage,positive.

  • 标签: 黄铁矿 成因古生代 元素地球化学 硫同位素
  • 简介:ThegeologicalfeaturesoftheLongshanAu-Sbdepositsaresystematicallydescribed.Mineralizationconditions,sourcesoforematerialsandmetallogeneticmechanismarealsoanalysedaccordingtosulfur,oxygenisotopecomposition,pyritetypomorphicfeaturesandfluidinclusionthermometrydating,Theresultsshowthatitisasedimentarymetamophichydrothermaldeposit.

  • 标签: GEOLOGICAL FEATURE Au-deposit GENESIS Longshan
  • 简介:DynamicalProcesandGenesisofLateTriasicSedimentFilinginOrdosBasin*JiaoYangquanLuZongshengZhuangXinguoYangShigongFacultyofEarth...

  • 标签: tectonic sequence dynamics ORDOS BASIN QINLING
  • 简介:OnOctober27,2001,alargeearthquakewithMs6.0,namedtheYongshengearthquake,occurredalongtheJinshajiangsegmentofChenghaifaultinYongshengCounty,YunnanProvince.ItisthelargesteventtooccuralongtheChenghaifaultinthelast200years.Theseismo-geologicalsurveyshowsthattheseismogenicfault,whichistheJinshajiangsegmentofChenghalfault,takesleft-lateralstrike-slipasitsdominantmovementpattern.Accordingtodifferencesinverticalmotion,motiontime,landformsandscales,theChenhalfaultcanbedividedintoeightsegments.TheJinshajiangsegmenthasaverticaldislocationrateof0.4mm/a,farlowerthanthemeanrateoftheChenghaifault,about2.0mm/a.It'sdeducedthatthetwosidesofJinshajiangsegment'stuck'tightlyandhinderedthestrike-slipoftheChenghaifault.ThestrongearthquakedistributionbeforethiseventshowsthattheJinshajiangsegmentwasintheseismicgap.TheChenghaifault,asaboundaryoftectonicsub-blocks,makestheNorthwestYunnanblockandtheMiddleYunnanblockmoveclockwise,andtheirmarginsmoveoppositelyalongtheChenghalfault.InthemotionprocessoftheChenghaifault,structuralhindranceandtheseismicgapofstrongearthquakesarepropitioustotheconcentrationandaccumulationofstructurestress.Asaresult,theYongshengMs6.0earthquakeoccurred.TheSujiazhuang-ShangangfusegmentissimilartotheJinshajiangsegmentwithalowverticalmotionrateof0.3mm/aandintheseismicgap.Soit'spostulatedthatthesegmentmaybecomeanewstructurehindrance,andtheYongshengMs6.0earthquakemaytriggertheoccurrenceoffuturelargeearthquakesalongthissegment.

  • 标签: 震源 地震事件 金沙江 云南
  • 简介:Athree-dimensional(3-D)oceanmodeliscoupledwithatwo-dimensional(2-D)seaicemodel,torevisitanonlinearadvectionmechanism,oneofthemostimportantmesoscaleeddygenesismechanismsinthemarginalicezone.Two-dimensionaloceanmodelsimulationssuggestnonlinearadvectionmechanismismoreimportantwhenthewatergetsshallower.Insteadofconsideringtheoceanasbarotropicfluidinthe2-Doceanmodel,the3-Doceanmodelallowstheseaicetoaffectthecurrentdirectlyinthesurfacelayerviaocean-iceinteraction.Itisfoundthatbothmesoscaleeddyandseasurfaceelevationaresensitivetochangesinawaterdepthinthe3-Dsimulations.Theverticalprofileofacurrentvelocityin3-Dexperimentssuggeststhatwhenthewaterdepthgetsshallower,thecurrentmovefasterineachlayer,whichmakestheseasurfaceelevationbenearlyinverseproportionaltothewaterdepthwiththesamewindforcingduringthesametime.Itisalsofoundthatbecauseoftheverticalmotion,themagnitudeofvariationsintheseasurfaceelevationinthe3-Dsimulationsisverysmall,beingonly1%ofthechangeinthe2-Dsimulations.Anditseemstheverticalmotiontobetheessentialreasonforthedifferencesbetweenthe3-Dand2-Dexperiments.

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