学科分类
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92 个结果
  • 简介:ThickenedheavyoilsinChinaaregeneticallycharacteristicofcontinenta.Astotheirphysico-chemicalproperties,theseoilsareveryhighinviscosityandlowinsulphurandtraceelementcon-tents.Inthegroupconstituents,theconcentrationsofnon-hydrocarbonsandasphalteneareveryhighbutthoseofsaturatedhydrocarbonsandaromaticsareverylow.Thegaschromatogramsofalkanesshowthattheseheavyoilshavehighabundancesofiso-alkanesandcyclichydrocarbons.Inallthesteroidsandterpenoids,bicyclicsesquiterpenoids,tricyclicditerpenoids,re-arrangedsteranesandgammaceranearestronglybildegradation-resistent.Theformationofheavyoilreservoirsiscontrolledmainlybylatebasinascendance,biodegradation,flushingbymeteoricwaterandoxidationintheoil-bearingformations.Ac-cordingtotheirformationmechanisms,heavyoilreservoirscanbeclassifiedasfourcategories:weatheringanddenudation,marginaloxidation,secondarymigrationandthickeningofbottomwater.Spacially,heavythickoilreservoirsaredistributedregularly:theyusuallyshowsomeparageneticrelationshipswithnormaloilreservoirs.Heavyoilreservoirsoftenoccurinstructuralhighsorinoverlyingyoungerstrata.Theirburialdepthisabout200m.Horizontally,mostofthemaredistributedonthemarginsofbasinsordepressions.

  • 标签: 地球化学 重油 中国 地质构造 石油 碳氢化合物
  • 简介:TheearlyMesozoicgranodiorites(ca.165Ma)inthenortheasternHunanProvince(NEH)haveSiO2=65.4-69.65%,K2O/Na2O=0.95-1.38andK2O+Na2O>6%,A/CNK=0.96-1.13andbelongtometaluminoushigh-Kcalc-alkalineseries.TheyarecharacterizedbyLREEandLILEsenrichment,andHFSEdepletionwithslightlynegativeEuanomalies(Eu/Eu*=0.62-0.90).Theinitial87Sr/86Srratiosareinrangefrom0.711458to0.717461,andεNdvaluesvaryfrom-9.4to-12.3,distinctfromthoseofthecontemporaneousgranodioritesmantle-derivedfromtheSoutheasternHunanProvince(SEH)(87Sr/86Sr(i)=0.707962~0.710396,εNd(t)=-6.98~-2.30).Bycontrast,suchsignaturesareroughlysimilartothoseoftheneighboringotherMesozoicgraniticplutons(Eu/Eu*=0.30-0.70;87Sr/86Sr>0.710;εNd=-12to-16)inSouthChinaBlock(SCB),whichhavebeeninterpretedastheremeltingproductsofPrecambrianbasement.TheProterozoiclower-middlecrustisanimportantcontributortothepetrogenesisoftheseearlyMesozoicgranodioritesintheNEH.AnintracontinentalextensionsettingispresentinthenortheasternHunanProvinceatthattimeduetothedemandofenoughthermaltransfer.

  • 标签: 花岗闪长岩 碱性钙 中生代 湖南东北部
  • 简介:Resultsobtainedfromthewide-spacedfloodplainsedimentsindicatethattheabundancesofPtandPdinfloodplainsedimentsare0.46ng/gand0.40ng/g,respectively.Threegeochemicalprovinces.Yunnan-Guizhou,Xinjiang-GansuandTibetofPtandPdwithacontentof0.8ng/g,weredelineated.

  • 标签: 富集 地球化学 泛滥平原沉积物 Pt
  • 简介:在中国的金geochemical省在这研究通过溪流沉积或集水沉积采样被描出。每个金geochemical省由2.5个ng/g封面的阀值价值描出几千公里的一个区域。是窘境geochemists传统地认为那块金牌不能在河或溪流里为长距离移居由于它的化学不活泼和高特定的密度形成一个大规模geochemical异例。在一台扫描电子显微镜(SEM)下面的量的分光镜的分析和观察显示亚微观的金粒子的存在(

  • 标签: 地球化学省 纳米尺度 黄金 微观 水系沉积物 扫描电子显微镜
  • 简介:FirstcomprehensiveinvestigationsoftheCuonadongleucograniteexposedinNorthHimalayangneissdomeofsouthernTibetarepresentedinthisstudy.TheSIMSU-Pbagesofoscillatoryzirconrimsscatterinawiderangefrom34.1to16.0Ma,andtheCuonadongleucograniteprobablyemplacedat16.0Ma.High-preci-sion40Ar/39Ardatingonamuscovitesampleyieldsanessentiallyflatagespectrumwithconsistentplateauandisochronages,indicatingthattheCuonadongleucogranitecooledbelow450℃at14Ma.BasedontheyoungestzirconU-Pbageandmuscovite40Ar/39Arage,theCuon-adongleucograniteexperiencedrapidcoolingwitharateof119℃/Myrfrom16to14Ma.ThegeochronologicaldataofthisundeformedleucogranitealsosuggestthattheductileextensionoftheSouthTibetanDetachmentSystemintheeasternHimalayaceasedbyca.14Ma.Furthermore,theinitialSr-NdisotopiccompositionsandNdmodelagesdemonstratethattheleucogranitewasderivedfrommeta-peliticsourcewithintheGreaterHimalayanCrystallineComplex.ThedistinctBadepletionwithhighRb/SrratiosandnegativeEuanomaliesmakeitclearthattheleucogranitemeltsweregeneratedbybreakdownofmus-coviteunderfluid-absentconditions.

  • 标签: LEUCOGRANITE SIMS zircon U-Pb DATING 40AR/39AR
  • 简介:GeochemicalBehaviourofRareEarthElementsintheErdaogouGoldDepositPangJiangli(庞奖励)(DepartmentofGeography,ShanxiNormalUniversity,...

  • 标签: RARE earths GEOCHEMISTRY Erdaogou gold DEPOSIT
  • 简介:Afixedlink(tunnelandbridge,intotal16km)wasconstructedbetweenSwedenandDenmarkduring1995-2000.Aspartofthework,approximately16milliontonnesofseabedmaterials(limestoneandclaytill)weredredged,andabout0.6milliontonnesofthesewerespilledinthewater.Modellingofthespreadingandsedimentationofthespilledsedimentstookplaceaspartoftheenvironmentalmonitoringoftheconstructionactivities.Inordertoverifytheresultsofthenumericalmodellingofsedimentspreadingandsedimentation,anewmethodwiththepurposeofdistinguishingbetweenthespilledsedimentsandthenaturallyoccurringsedimentswasdeveloped.Becausethespilledsedimentstendtoaccumulateattheseabedinareaswithnaturalsedimentsofthesamesize,itisdifficulttoseparatethesebasedpurelyonthephysicalproperties.Thenewmethodisbasedonthegeo-chemicaldifferencesbetweenthenaturalsedimentintheareaandthespill.ThebasicpropertiesusedarethehighercontentofcalciumcarbonatematerialinthespillascomparedtothenaturalsedimentsandthehigherCa/Srratiointhespillcomparedtoshellfragmentsdominatingthenaturalcalciumcarbonatedepositioninthearea.ThereasonforthesedifferencesisthatcarbonatederivedfromrecentshelldebriscanbediscriminatedfromDanienlimestone,whichisthematerialinwhichthemajorityofthedredgingtookplace,onthebasisoftheCa/Srratiobeing488inDanienLimestoneand237inshelldebris.Thegeochemicalrecognitionoftheoriginofthesedimentsprovedusefulinseparatingthespilledfromthenaturallyoccurringsediments.Withoutthisseparation,validationofthemodellingofaccumulationofspilledsedimentswouldnothavebeenpossible.Themethodhasgeneralvalidityandcanbeusedinmanysituationswheretheoriginoragivensedimentissought.

  • 标签: 沉积物 数字模型 地球化学 溢出
  • 简介:Theresultsof118REEanalysesofLi-FgranitesfromSouthChinaandothercountriesindicatethattherearethreevariationtypesofREEpatterncurveswithdifferentevolutiontrendsfromearlytolatestagesofLi-FgranitecomplexoffromlowertoupperpetrofaciesoftheLi-Fgranitebody;(1)thedecreasing,(2)theincreasing,and(3)thesaltatoryvariationtypes.Thefirstvariationtypeiscalledthepositiveevolutiontype,attributedtocrystallizationdifferentiation.Thesecondiscalledthereversionevolutiontype.whichrepresentsliquidsegreationdominatedbyvapor-liquiddistillation.Thethirdiscalledthesaltatoryvariationtype,whichisformedfromliquidsegregationdominatedbyimmiscibilty,Therefore,theindicaticesofliquidsegregationdominatedbyimmiscibilityarethesaltatoryvariationtypeofREEpatternevolutionandtheseparationofthemainevolutiontrendlineseitherfromthesub-evolutiontrendlinesorfromthecompositionpointsofLi-FgranitesinthediagramsofREE-(La-Yb)NandLa/Sm-La,Theindicatricesofliquidsegregationdominatedbyvapor-liquidfractionaldistillationarethereverstionevolutiontypeofREEpatterncurvesandthemainevolutiontrendlinesofLi-Fgranitesdirectingtotheupperright-handontheREE-La/Yb)NandLa/Sm-Ladiagrams.

  • 标签: 稀土元素 地球化学 花岗岩 岩浆
  • 简介:Guizhouisoneofthedominatingkarstregions,wherelateriteiswidespread,inChina.Seventy-twolateritesamplesweretakenfromtwelvelateritesectionsinthekarstareasofGuizhouProvince,whicharepossessedoftypicalsubtropicalkarstgeomphologicalandecologicalenvironmentalfeaturesandhaveevolvedcompletelyfromdolostonesandlimestones.Intermsofthemajor,traceandREEdetaforthdsamplesthispaperdiscussesthegeochemicalcharacteristicsoflateriteinthekarstareaswithanattempttodisclosethegeochemicalprocessandevolutionaryruleoflateriteformation.Therehavebeeninvolvedthreeimportantpedogeneticgeochemicalprecessesintheformationoflateriteinthekarstareas:(1)enrichmentofsiliconandaluminumanddepletionofcalciumandmagnesium;(2)enrichmentofironandmanganese;and(3)enrichmentofaluminumanddepletionofsilicon.Duringtheformationandevolutionoflaterite,obviousenrichmentanddifferentiationoftraceelementssuchasCu,Pb,Zn,Ni,Co,Cr,Pb,F,Cl,andAscanbeobserved,butfortherare-earthelements,theirenrichmentisremarkableagainstaweakdifferentiation.TheREEdistributionpatternsinthelateritearesimilartothoseofitsparentalcarbonaterocks.

  • 标签: 红土 土壤地球化学特征 喀斯特地区 稀土元素分布模式 贵州
  • 简介:ThecharacteristicstructuresofthePrecambrianchertsfromtheGusuisection,Guangdong,Chi-na,includebeddedstructure,laminatedstructure,massivestructureandpseudobrecciatedstructure.ThechertischaracterizedbyconsistentlylowabundanceofTiO2,Al2O3andmosttraceelements.Howevver,itisenrichedinBa,As,Sb,HgandSe.InAl-Fe-Mnternarydiagrams,itfallsintothe'hydrothermalfield'.Correspondenceanalysisandfactoranalysisshowthatmanyelementsshowupinthefactorthatrepresentstheleachingofcountryrocksbyhydrothermalsolutions,andaretheverycharacteristicelementassociationfothegeochemicallyanomalousSouthChinabasement.Petrologicandgeochemicalevidencesuggestsahydrothermaloriginforthechert.ThechertmayhavebeenformedinaPrecambrianfiftoranextensionzonedevelopedwithintheYunkaimarginalgeosyncline,withafaultsystemlinkingittoanunknownheatsourceatdepth.

  • 标签: 前寒武纪 中国南部 层状黑硅石 多元分析 热液起源 岩石记述学
  • 简介:Asequentialextractionmethodforthefractionationofphosphorus(P)inlakesedimentswasusedtoanalyzephosphorusfractionsofsedimentstakenfromthreelarge,shallow,eutrophicfreshwaterlakesofChina-TaihuLake,ChaohuLake,andLongganLake.AllthreelakesarelocatedinthelowerreachesoftheChangjiangRiver(YangtzeRiver).InTaihuLakeandChaohuLake,algaebloomsoccurredeveryyear,whileLongganLakewasamacrophyte-dominatedlake.Resultsshowedthatexchangeablephosphorusfractionsweremuchhigherintheeutrophiclakesedimentsthaninthemacrophyte-flourishinglakesediment.Also,theratioofFe:Pinthesedimentsofthealgae-predominantlakeswasgenerallymuchlowerthanthatinthemacrophyte-predominantlakes.Thus,thegeochemicalfractionsofphosphorusinsedimentshadacloserrelationshipwiththetypeofaquaticvegetation.

  • 标签: 藻花 大型植物 沉积物 湖泊 水文化学
  • 简介:冲绳马槽(OT)是在在菲律宾的海板的subduction的影响下面的一个起始的传播阶段的背弧盆。在这研究,我们在OT分析了玄武岩的玻璃的geochemical作文并且在暗岩讨论了不同magmatic来源,进化,和subducted部件的效果。我们的结果证明OT的中间、南部的区域展出与一个充满铁的tholeiite系列一致的特征。当包括Nb在高地力量元素(HFSE)弄空时,踪迹元素比例遵循背弧盆暗岩,在包括Rb的大离子亲石元素元素(LILE)的富人,Ba,Pb,U,和Th的典型蜘蛛图模式特征,Ta,Zr,Hf,并且Ti。稀土元素元素(REE)的分发与由正确倾斜的轻稀土元素元素(LREE)的丰富也一致。充实的披风类型的增加我(EMI)材料以及披风异质可能在不同区域导致了丰富的可变的度。当斜长石的开发部分被限制时,中间的马槽的岩浆来源向辉石经历了结晶化,并且尖晶石和橄榄石的结晶化完全停止。同时,南部的OT岩浆来源的结晶化被橄榄石并且包括斜长石,辉石,和磁铁矿的形成统治(或titanomagnetite)。最后,这研究的结果证明在中间的暗岩的90%Th,在南部的暗岩的95%Ba,50%-70%Th和70%-90%Ba从subducted部件发源。不同subducted部件影响可以由于不同subduction地区是结构的特征。

  • 标签: 迹元素 玄武岩 特征 玻璃 冲绳 轻稀土元素
  • 简介:ThereoccurabundantchertsintheMesozoicandCenozoicstratainsouthernTibet.Someofthempossesscharacteristichydrothermalstructuressuchaslayered,laminated,massiveandbrecciastructures.RatiosofAl/(Al+Fe+Mn),Co/Ni,Fe/TiandTiO2-Al2O3demonstratethattheiroriginisrelatedtohydrothermalsedimentation.ThechertformationshavecloserelationshipwithSb,Auandpoly-metallicmineralization,andtheore-formingfluidshowstrongcorrelationwithfossilhydrothermalwater.

  • 标签: 沉积结构 热液沉降 矿化作用 西藏 地质条件
  • 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:Thereisadearthofinformationaboutthedistributionoftraceelementsinkerogenfromshalerocksdespiteseveralreportsontraceelementcompositioninmanyshalesamples.Inthisstudy,traceelementsinshalerocksandtheirresidualkerogensweredeterminedbyinductivelycoupledplasma–massspectrometry.Theresultsfromthisstudyshowredox-sensitiveelementsrelativelyconcentratedinthekerogensascomparedtotheshales.Thismaybeprimarilyduetotheadsorptionandcomplexationabilityofkerogen,whichenablesenrichmentinNi,Co,Cu,andZn.Fortherareearthelements(REEs),distinctdistributioncharacteristicswereobservedforshalesdominatedbyterrigenousmineralsandtheirkerogencounterparts.However,shaleswithlessinputofterrigenousmineralsshowedsimilarREEdistributionpatternstotheirresidualkerogen.ItisspeculatedthatthedistributionpatternsoftheREEsinshalesandkerogensmaybesourcerelated.

  • 标签: SHALE KEROGEN Trace elements REES
  • 简介:从在尼日利亚的南部的Benue马槽的三岩石层位学的继任的沙岩的Geochemical研究为沙岩的geochemical描述被承担,并且估计他们的stratigraphic和来源进化。主修,痕量元素数据从露头沙岩样品被获得。SiO2/Al2O3,Fe2O3/K2O比率和CaO内容被用来描绘白垩纪沙岩进Al富有、高、低的Fe2O3/K2O比率沙岩。结果显示有geochemical特征,从Asu河组,越过继任显示stratigraphic趋势Eze-Aku组到可以从不同来源地面暗示不连续的进化的proto尼日尔三角洲继任前寒武纪并且供应了沉积的中生代年龄。Asu河组沙岩有更低的SiO2,艾尔2O3,Fe2O3和更高的MgO;当proto尼日尔三角洲沙岩有更高的SiO2,艾尔22,CaO,碱和更低的MgO>O3,Fe2O3和更低的碱和CaO。这些断绝意味着在白垩纪时间期间影响了南部的Benue马槽的构造推动的影响。在TiO2/Al2O3,Fe2O3,Cr和Zr建议一逐渐地对有时间的depositional盆的mafic贡献。有时间的改变增加的化学索引,可能建议在内地的更强烈的捱过政体与时间发展了。

  • 标签: 地球化学 特征 储层沥青 烃源岩 对比