简介:TheIrtyshshearzone(ISZ)ofAltairegionisthelineamentstructureofthecollision-suturetype,wheregranitesofKalbacomplexandgranodioritesofZmeinogorskcomplexareexposedtoregionalgneiss-formationandstress-metamorphicalterations.Thisstudyisbasedondetailedstructuralobservationsatspecialgroundsusingopticalandelectronmicroscopy,andonthebehavioranalysisofisotopicsystemsfromalteredgranitoids.WithintheISZareawehaveestablishedthecontinuousrowsofgranitoidstress-metamorphismfrominitialrecrystallizationofprotolite,itscataclasisandmechanicalflaringuptocompleterecrystallizationwithalterationofmineralcompositionandformationofthestreakycomplexesofgranitetectonitesofblastomyloniteandblastocataclasitetypes.Thedirectedalterationofrockshasseveralimpulseandisexpressedbyachangeinmorphologyofmineralgrainsandtheirrelations,magnificationofdeformationcomponentintherockstructure,andformationofnewmineralphasesonthebasisofinitialoneswithoutsurfacefluidization.Attransformationofisotopicsystemsfromgranitoid,theirfeldspars,biotiteandhornblende,wecanobserve'rejuvenation'oftherocksubstratefrom270-290MaforKalbagranitoidsto220-235Mafortheirtectonites,andforRudnyAltaigranodiorites,theirageschangesfrom285-317Mato232-257Mafortheirtectonites.
简介:<正>Irtyshshearzoneisastretched,butrelativelynarrownearfaulttectoniczone,whichischaracterizedbythefollowingfeatures:a)generalsturctureanisotropy(310-320o)withpre-dominanceofsymmetricalrelationshipsofplanarandlineartypes;b)predominantdevelop-mentofbendedblastomyolnite,blastocataclasiteandmetamelangefomations;c)regional,butnon-uniformfoliationofricksandgeneralmanifestationofstructuresoftheshearingflow;d)separationofnumerouslensesofmingmatite-likeandpegmatoidformations,smallintrusionsofleucocraticgranites,granite-porphyresandgranite-aplitesanddike-likebodiesofgabbro-dyabaesandultrabasicrlcks,rarely.
简介:AninvestigationofmacrobenthosinthelittoralzonewascarriedoutinTangguDistrict,TianjinCityinJune2003.Thisinvestigationwastheonlyintegratedonesince1983there.Somethingaboutmacrobenthosinvestigationwasreportedinthispaper.Theresultsshowedthatthebiomassofmacrobenthosofthatareawasalmostatthesamelevelasthatof1983,andthedensityofmacrobenthosincreasedalittle.ThebiomassofMactraveneriformishasgreateffectontheaveragebiomassofthatarea.Thediversityofmacrobenthoshaschangedobviously,and5or6kindsofmacrobenthoshavebecomeextinctordecreasedgreatly.Sotheecologicalstructureofmacrobenthoshasbecomesimplerandunstable.Inaddition,someecologicalmethodstoremedytheareaarediscussedinthispaper.
简介:Deepstructureandmaterialpropertiesoffaultscanbeunderstoodbyobservingandsimulatingtheparticularphaseinafaultfracturezone.Thispaperreviewsthedevelopmentoffault-zoneseismicwavesintheseismologicaldomain.Thepresentresearchstatusoffault-zoneheadwaveandtrappedwavearesummarizedsystematically.Basedonrecentprogressinthisfield,thepaperdiscussestheprospectontheutilizationofseismicwaveinfaultstructureresearch.
简介:KazkeaertefaultzoneisrecognizedasanimportantboundarybetweenPamirandTianshanCenozoicMountainbeltsinthewestofTarimBasin.Itisanactivethrustfaultandcanbedividedintothreesegmentsfromthewesttoeast:Jilekeroutefaultzone,Wuqiaearthquakefaultzone,MushifaultzoneaftergeologicalinvestigatingandmappingalongPamirpiedmont.Basedonthefaultedlandformaswellasdeformationanddisplacementofyoungdepositlayers,theslipratesofKazkeaertefaultzonesincethelateQuaternaryarebrieflystudied.Theresultshowsthattheaveragesliprateoffaultisdifferentiatealongdifferentsegments.
简介:Thecentral-axiszoncformedinMesozoic-CeozoiceraandoccurrcdalongLanping-Simaodepres-sion,Yunnan,isaspccialtcctonicunit’ItisnamedfortheLanping-Pucrtectono-thcrmo-metamorphicupwarpingzone.Itsmaincharacteristicsarc:1.Therockhasbcenmetamorphosedandtherccenthotspringsoccura1ongthezone,whichisahigh-tempcrat
简介:TheRockyMountainFoothillsliealongtheeasternmarginoftheRockyMountainfold-thrustbelt.TheareahasbeenthefocusofextensiveresearchaimedatlocatingoilandgasfieldswiththepotentialtobeusedasCO_2storagetraps.Inthisstudy,weuseaseismiclinefromtheCanadianRockiestointerpretthegeologicstructuresalongacross-sectionparalleltothetectonictransportdirection.Wethencompareourresultswiththoseofpreviousstudies.ThesectionwasrestoredusingtheMOVEsoftware(manufacturedbyMidlandValleyExplorationLtd.).Theprimaryobjectivesofthisworkare:(1)toconductastratigraphicandstructuralinterpretationofa2Dseismicprofile;and(2)toconductacross-sectionalrestorationofthestructuresinordertovalidatetheseismicinterpretationintermsofCO_2storagecandidates.Additionaldatasourcesincludemapsofthesurfacegeology,whichshowthattheageofhorizonsdecreasefromwesttoeast,andstratigraphicandstructuralprofilesderivedfromwelllogs.Theresultsofourstructuralrestorationindicateadetachmentfaultbetweentheforelandandhinterland.ThisfaultisresponsibleforthecuttingandsubsequentupwardsandeastwardsmovementofastratumlocatedbetweenthebasementandtheLateDevonianformation.Largethrustfaultsareresponsibleforthedeformationofstrata(throughbothfoldingandfaulting)
简介:1.ObjectivesTheMoheBasininHeilongjiang,ChinahasaNEEthrustnappebelt,whichwasassembledbytherootzone,middlethrustzoneandthrustfront,north-southandnorth-eastnormalfaultswiththreetectonicactivitiesoftheMiddleJurassicto.Eocene,theMiocene,andtheEarlytoMiddlePleistocene.Themiddlethrustzoneandthrustfronthasalargenumberoffolds,thrustfaults,fracturesandglutenites,whicharethemajorstructuresofgashydrateaccumulationintheMoheBasin.
简介:Thepatternofthesubtletraps,inwhichoilandgasaccumulated,intheburied-hillfaultedzoneintheJiyangsagisverycomplicated,andveryhardtoprospect.Thepaperanalysesthemaindifficultiesinexploringthecomplicatedburied-hillfaultedzoneoftheareafromapointofgeology.Thetypicalpatternoftheburied-hillzoneintheJiyangsagisstudiedusingtheforwardmodeling.Target-orientlayoutdesignandfull3-Dseismictechnology,whichareusefulforoilandgasexplorationonthezone,areputforward.Takingtheexplorationforoilandgastrapsonthezoneasanexample,certaintechnologiesandtheeffectoftheirapplicationsaboutthedesignfortargetacquisition,acquisitiononawide-azimuth,pointsourcesandpointreceiversarediscussed.
简介:Xiangshanbayisanarrowsemi-closedbayandsituatedonthenorthwesterncoastoftheEastChinaSea.Overpastdecades,ithasbecometoamajorbaywithintensivehumanactivities,denseurbanizedarea,andpoorwaterquality.Theaimofthispaperwastorevealtheecologicalstatusthroughtheelucidationofthespeciescomposition,abundance,biomassanddiversityofmacrobenthosinthisbay.SixintertidalsectionsweresurveyedfromJanuary2007toNovember2008quarterly.SectionsTG,HDandXHarelocatedinthethreeinnerbays,sectionsQJandWSarelocatednearthethermalpowerplants,andsectionXXislocatedattheouterpartofXiangshanBay.Greatvariationsinmacrobenthoscommunitywereindentified,andthespeciescompositionofthecommunityinthepresentstudyshowedthedominanceintheorderofmolluscs(bivalvesandgastropods),crustaceansandothers,andonlyfewPolychaetawererecorded.Onlythreedominantspecies,Littorinabrevicula,Ilyplaxtansuiensis,andCerithideacingulatawerecollectedinallthesections,andatotalof19dominantspecieswererecordedonlyinonesection.Two-wayANOVAanalysesofabundanceindicatedthatthereweresignificantdifferencesamongsectionsorseasons.Shannon-Wienerdiversityindex(H’)haditsmaximum(2.45)insectionQJ,andminimum(1.76)insectionTG.Multipleirregulark-dominanceplotsclearlyshowedthatthestudyareawaspollutedandthemacrobenthoscommunitywasunderstress.WeconcludethatthemacrobenthosofXiangshanBayhavebeendisturbedbyhumanactivities,especiallyattheinteriorbay.
简介:Itisfoundbyfieldinvestigationthatthenearhorizontaltopsurfaceofthebrownorbrick-redhydrothermalalterationzonevariesobviouslyinelevationatdifferentsectionsofthesamelayeronthecaldera'sinnerwallofTianchi,withthatatthenorthsectionneartheTianwenPeakabout110mhigherthanthatatthesouthneartheJiangjunPeakinKorea.Thetopsurfaceofthehydrothermalalterationzonecanbetakenaskeyhorizontotectonicmovement.ThedifferenceindicatesthatthetotalupliftheightoftheNWwalloftheLiudaogou-TianchiJingfengshanfault,theprincipalfaulttrendingNEatTianchi,isbiggerthanthatoftheSEwalleversincetheoccurrenceofhydrothermalalteration.ThisalsoexplainswhythetopographyinthenorthwestsideofTianchiissteeperandwithmoredevelopedriversystemthaninthesoutheast.TheupliftingofthenortheasternwallisbiggerthanthatofthesouthwestalongtheprincipalNW-trendfault,namely,theBaishanzhen-Tianchi-Jincefault.Itisobservedfromcharactersofhydrothermalalterationandthepalaeoresiduum,thattherecentverticalmovementratealongtheprincipalNE-trendfaultislargerthanthatoftheprincipalNW-trendfault.ThetwofaultsintersectatTianchi,dividingthevolcanointo4blocks,withtheupliftmagnitudesdecreasingsuccessivelyintheorderofthenorth,thewest,theeastandthesouthblock.ThebiggestupliftofthenorthblockcorrespondswelltotheshallowmagmabatchinthenorthofTianchiobservedbyDSSandtelluricelectromagneticsounding,andetc.andtheymayberelatedwiththecauses.
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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.
简介:Iceloadisthedominativeloadinthedesignofoffshoreplatformsintheicezone,andtheextremeiceloadisthekeyfactorthataffectsthesafetyofplatforms.ThepresentpaperstudiesthestatisticalpropertiesoftheglobalresistanceandtheextremeresponsesofthejacketplatformsinBohaiBay,consideringtherandomnessoficeload,deadload,steelelasticmodulus,yieldstrengthandstructuralmemberdimensions.Then,basedontheaboveresults,anefficientapproximatemethodoftheglobalreliabilityanalysisfortheoffshoreplatformsisproposed,whichconvertstheimplicitnonlinearperformancefunctionintheconventionalreliabilityanalysistolinearexplicitone.Finally,numericalexamplesofJZ20-2MSW,JZ20-2NWandJZ20-2MUQoffshorejacketplatformsintheBohaiBaydemonstratethesatisfyingefficiency,accuracyandapplicabilityoftheproposedmethod.