简介:FollowingtherecommendationoftheInternationalCommissiononStratigraphy(16votesYes[94%],1abstention,2votesnotreceived),theGlobalboundaryStratotypeSectionandPoint(GSSP)forthebaseoftheTuronianStageoftheCretaceousSystemisdefinedasthebaseofbed86oftheBridgeCreekLimestoneMemberoftheGreenhornLimestoneFormationatthewesternendoftheDenverandRioGrandeRailroadcutnearthenorthboundaryofthePuebloReservoirStateParkRecreationArea,westofPueblo,Colorado,USA.ThisGSSPhorizonisalsoexposedandprotectedintheadjacentstaterecreationarea.ItcoincideswiththefirstoccurrenceoftheammoniteWatinocerasdevonense,isinthemiddleofaglobalpositiveexcursioninCarbon-13isotopes,andisbracketedbywidespreadbentonitesthathaveyieldedagesof93to93.5Ma.
简介:TheresistivityexperimentalmeasurementsofcoresamplesdrilledfromlowpermeabilityreservoirsofOrdosBasin,NorthwestChina,illustratethatthecementationfactorsarenotagminate,butvaryfrom1.335to1.749.Thisleadstoachallengefortheestimationofwaterandhydrocarbonsaturation.BasedontheanalysisofPurcellequationandassumptionthatrockresistivityisdeterminedbytheparallelconnectionofnumerouscapillaryresistances,atheoreticalexpressionofcementationfactorintermsofporosityandpermeabilityisestablished.Then,cementationfactorcanbecalculatediftheparametersofporosityandpermeabilityaredetermined.Inthefieldapplication,porositycanbeeasilyobtainedbyconventionallogs.However,itisatoughchallengetoestimatepermeabilityduetothestrongheterogeneityoflowpermeabilityreservoirs.Thus,theSchlumbergerDollResearch(SDR)modelderivedfromNMRlogshasbeenproposedtoestimatepermeability.BasedontheanalysisofthetheoreticalexpressionsofcementationfactorandSDRmodel,anovelcementationfactorpredictionmodel,whichisrelevanttoporosityandlogarithmicmeanofNMRT2spectrum(T2lm),isderived.TheadvantageofthismodelisthatalltheinputinformationcanbeacquiredfromNMRlogsaccurately.Inordertoconfirmthecredibilityofthenovelmodel,theresistivityandcorrespondinglaboratoryNMRmeasurementsof27coresamplesareconducted.Thecredibilityofthemodelisconfirmedbycomparingthepredictedcementationfactorswiththecoreanalyzedresults.Theabsoluteerrorsforallcoresamplesarelowerthan0.071.Oncethismodelisextendedtofieldapplication,theaccuracyofwaterandhydrocarbonsaturationestimationwillbesignificantlyimproved.
简介:ThisstudyreportszirconU-PbandHfisotopesandwhole-rockelementaldataforgranodioritesfromtheEastKunlunorogen.ThezirconU-Pbdatingdefinestheircrystallizationageof235Ma.Therocksarecharacterizedbyhigh-Kcalc-alkaline,magnesianandmetaluminouswith(K2O+Na2O)=6.38wt.%–7.01wt.%,Mg#=42–50[Mg#=100×molarMg/(Mg+FeOT)],A/CNK=0.92–0.98,coupledwithhighεHf(t)valuesfrom-0.65to-1.80.Therockswerederivedfrompartialmeltingofajuvenilemaficcrustalsourcewithinnormalcrustthickness.Thejuvenilelowercrustwasgeneratedbymixinglithosphericmantle-derivedmelt(55%–60%)andsupracrustalmelt(40%–45%)duringtheseafloorsubduction.TogetherwithavailabledatafromtheEastKunlun,itisproposedthatthestudiedMiddleTriassicgranodioriteswereformedinpost-collisionalextensionsetting,inwhichmeltingofthejuvenilelowercrustinresponsetothebasalticmagmaunderplatingresultedintheproductionofhigh-Kgranodioriticmelts.
简介:ObjectiveThenearlyparallelN–S-trendingriftsinsouthernTibetrepresenttheE–WextensionoftheTibetPlateau.MostdatawhichconstrainedtheageoftheextensionaldeformationcomefromisotopicdatingofthedikesprobablyrelatedtotheactivityofthenearlyN–Sfaultingandmicasfromhydrothermalactivityandthelowtemperaturethermochronologyofplateauuplift.Previous
简介:我们把周围的噪音断层摄影术用于在从76个车站的地区性的网络的2008年1月1日和2008年12月31日之间的地震数据由中国地震管理部署了的连续三部件的宽带。周围的噪音跨关联被执行生产每车站对的草地功能。在从6~50s的时期以内,瑞利和爱波浪分散曲线用多重过滤器分析方法被测量。然后三维(3-D)从表面的S波浪速度结构击倒到70km从瑞利和爱波浪分散结果被转换。获得的S波浪速度地图在学习区域与不同地质、构造的特征显示出强壮的侧面的变化和相互关联很好。四川盆由于厚沉积存款,但是高在浅深度显示低速度在中间降低外壳中的速度;东方西藏的高原清楚地在它与外壳的流动模型建议解释机制一致的mid-to-lower外壳中与一个低速度的地区被展示高举并且为西藏的高原的变丑的模式。同时,我们的结果也展出外壳的厚度从东方西藏的高原减少了到四川盆。
简介:TightzonesofthegasbearingKanganandDalanformationsoftheSouthParsgasfieldcontainaconsiderableamountofunsweptgasduetotheirlowporosity,lowpermeabilityandisolatedporetypes.Thecurrentstudy,integratescoredata,rockelasticpropertiesand3Dseismicattributestodelineatetightandlow-reservoir-qualityzonesoftheSouthParsgasfield.Inthefirststep,thedynamicreservoirgeomechanicalparameterswerecalculatedbasedonempiricalrelationshipsfromwelllogdata.Thelog-derivedelasticmoduliwerevalidatedwiththeavailablelaboratorymeasurementsofcoredata.CrossplotsbetweenestimatedporosityandelasticparametersbasedonYoung'smodulusindicatethatlowporosityzonecoincidewithhighvaluesofYoung'smodule.Theresultswerevalidatedwithpetrographicstudiesoftheavailablethinsections.Thecoresampleswithlowporosityandpermeabilityarecorrelatedwithstrongrockswithtightmatrixframeworksandhighelasticvalues.Subsequently,rockelasticpropertiesincludingYoung'smodulusandPoisson'sratioalongwithporositywereestimatedbyusingneuralnetworksfromacollectionof3Dpost-stackseismicattributes,suchasacousticimpedance(AI),instantaneousphaseofAIandapparentpolarity.Distinguishinglowreservoirqualityareasinpayzoneswithunsweptgasisthenfacilitatedbylocatinglowporosityandhighelasticmodulusvalues.Anhydritezonesareidentifiedandeliminatedasnon-payzonesduetotheircharacterizationofzeroporosityandhighYoungmodulusvalues.Themethodologydescribedhasapplicationsforunconventionalreservoirsmoregenerally,becauseitisabletodistinguishlowporosityandpermeabilityzonesthatarepotentiallyproductivefromthoseunprospectivezoneswithnegligiblereservoirquality.
简介:ThetransitionzonebetweentheEastAsiaandCentralAsiacrustobodlesisnotonlyadiwaregion,butalsoagigantictectono-metallogenicbeltinAsia.IttrendsN-S,liesbetweenlong.100°-107°Eandlat.14°-62°N,hasalengthof4600kmandfurtherextendssouthwardandnorthward.Themainfeaturesofthebeltareasfollows:(1)Thebc1tcon8istsofotc