简介:<正>ONSOUTHERNSTRETCHOPTHES-NTECTONICBELT,CHINAChenGuanghaoandWeiZhoulin(ChangshaInstituteofGeotectonic,AcademiaSinica,Changsha,410013,Hunan,China)S-Ntectonicbelt,southstretching,boundingbeltItcanbeinferredfromthegeophysicaldata,linearstructures,tectonicevolu-tionhistoryandmetallogenythattheS-NtectonicBeltstretchesfurthersouthinadifferentdi-rectionandmannerafterinterceptedbytheRedRiverFault,Thestretchingsegmentistheim-portanttectonicboundaryinIndo-AsiaandassiminlatestheS-Ntectonicbeltwithsomediffer-ences.
简介:AccordingtoVeningMeinesz-Moritz(VMM)globalinverseisostaticproblem,eithertheMohodensitycontrast(crust-mantledensitycontrast)ortheMohogeometrycanbeestimatedbysolvinganon-linearFredholmintegralequationofthefirstkind.HeresolutionstothetwoMohoparametersarepresentedbycombiningtheglobalgeopotentialmodel(GOCO-03S),topography(DTM2006)andaseismiccrustmodel,thelatterbeingtherecentdigitalglobalcrustalmodel(CRUST1.0)witharesolutionof1o×1o.ThenumericalresultsshowthattheestimatedMohodensitycontrastvariesfrom21to637kg/m3,withaglobalaverageof321kg/m3,andtheestimatedMohodepthvariesfrom6to86kmwithaglobalaverageof24km.ComparingtheMohodensitycontrastsestimatedusingourleastsquaresmethodandthosederivedbytheCRUST1.0,CRUST2.0,andPREMmodelsshowsthatourestimateagreesfairlywellwithCRUST1.0modelandratherpoorwithothermodels.TheestimatedMohodepthsbyourleast-squaresmethodandtheCRUST1.0modelagreeto4.8kminRMSandwiththeGEMMA1.0basedmodelto6.3km.
简介:TheJiamusimcdianmassifislocatcdaboutlittlcXinganlingtoLaoycling,casternHeilongjiangProvince.Beinginaccordwiththediwathcory,thcJiamusipalaco-mcdianmassifdevclopspre-geosyn-clinlarchacansialiccrust.KhondalitescricsinthcJiXidistrictmaybcrcputcdasrcprcscntivc,isotopicageofwbichis25OOMa.ThcrcarethcDongfc
简介:KarstrocksfromtheHuanglongFormationexposedatthemarginoftheEasternSichuanBasincanbedividedintofourtypes:slightlycorroded,moderatelycorrodedporous,intenselycorrodedbrecciatedandintenselycorrodedandreplacedsecondarycalcickarsticrocks.Thecarbon,oxygenandstrontiumisotopecompositionsofthevariouskarstrocksareanalyzedsystematicallyandcomparedtorockswithoutkarstcorrosion.Theresultsindicatethat(1)theHuanglongFormationintheeasternSichuanBasinwasarestrictedbaysuppliedandcontrolledbyfreshwaterinwhichmudmicriteandmud-dolomicriteexhibitlowδ13Candδ18Ovaluesandhigh87Sr/86Srratios;(2)alltypesofkarsticrocksinthepaleokarstreservoirsoftheHuanglongFormationintheresearchareaareaffectedbyatmosphericfreshwaterwiththeδ13Candδ18Ovaluesand87Sr/86Srratiosintheoriginalformationapproachingthoseofatmosphericfreshwater,whichreflectsancienthydrologicalconditions,fluidproperties,isotopicsourceandthefractionationeffect;(3)theintenselycorrodedandreplacedsecondarylimestoneisaffectedbyavarietyofdiageneticfluids,oftenreflectedbyδ13Candδ18Ovalues,whilethe87Sr/86Srratiosexhibitthestrongdegreeofthecorrosion;(4)aftercomparingthe87Sr/86Srratiosofeachtypeofkarstrock,thediageneticfluidsaredeterminedtobemainlyatmosphericfreshwater,anddependingonthestrengthofcorrosion,andthelow87Sr/86Srratiofluidsinthelayerwillparticipateinthekarstprocess.Thecarbon,oxygen,andstrontiumisotopesofdifferentkarsticreservoirscanprovidemeaningfulgeochemicalinformationforforecastingandevaluatingthedevelopmentanddistributionrulesoftheHuanglongFormationatthemarginoftheeasternSichuanBasinintimeandspace.更多还原
简介:<正>1IntroductionTheundergroundbrineresourcesdistributingwidelyinSichuanBasin,Chinahavedrawnworldwideattentionduetotheirunusualelementabundanceandexcellentquality.
简介:这研究在Balong提供n链烷和Holocene黄土的花粉记录()镇,Dulan()县,Qinghai()省,和环境变化从同意很好的两个记录重建了。过去的气候变化的三个阶段被n链烷和花粉代理的变化译解。在5370一BP前,气候温暖干燥却稍微潮湿,相应于Mid-Holocene气候的最佳;53703830一BP,气候或者变化了在之间温暖干燥稍微潮湿、温暖干燥,从Mid-Holocene气候的最佳显示转变到迟了的Holocene冷时期;在3830一BP以后,气候主要是温暖干燥的。温暖的凉爽、极其干燥的气候被n链烷和花粉代理在30402600一BP期间记录,建议环境演变为荒芜或咸的湖,根据在西方的周王朝的冷、高度经常的自然灾难时期(ca。29962721一BP)在中国。
简介:ObjectiveThenearlyparallelN–S-trendingriftsinsouthernTibetrepresenttheE–WextensionoftheTibetPlateau.MostdatawhichconstrainedtheageoftheextensionaldeformationcomefromisotopicdatingofthedikesprobablyrelatedtotheactivityofthenearlyN–Sfaultingandmicasfromhydrothermalactivityandthelowtemperaturethermochronologyofplateauuplift.Previous
简介:欧洲建成32家世界地质公园,中国建成20家世界地质公园,地质公园建设已经成为世界关注的热点。第1届世界地质公园大会在北京召开,第2届世界地质公园大会在英国北爱尔兰的贝尔法斯特召开,第3届世界地质公园大会于2008年6月22~26日在德国的奥斯纳布吕克市召开。
简介:由露头,日志和核心数据识别古老的河的词法类型是容易的。然而,隧道的水平分发和几何学能被依靠3-D仅仅鉴别并且预言地震数据。特别,地震地平线切的3-D能在蜿蜒地流的河,支流隧道和低蜿蜒的隧道的沙岩预言起一个重要作用。每个微外形单位包括主要隧道,例如蜿蜒或分叉的隧道,早朝,裂缝隧道,叶舌裂缝展开,泛滥平原等等能被识别。编织隧道沙岩是平面平坦侧面连接沙身体和厚主要隧道带的分发能仅仅从3-D被识别地震数据。因为编织沙岩是无所不在的,他们的出现和分发不需要被预言。通常,煤速度是那么低的它能在煤阶层创造强壮的振幅思考。它因而隐藏振幅作答到吻合能从3-D被识别的隧道沙岩地震倒置数据有时。充满泥的低蜿蜒的河的案例研究与3-D识别了地震数据显示如此的沙身体的规模和width-to-thickness比率是小的,旁边地不连接,并且通常在干燥气候条件下面发生在一把冲积扇子的远或进一步的部分上。有时,沿着地平线的每个思考事件的地震属性的抽取被期望最大化古老的隧道的空间进化的表示。
简介:The3^rdInternationalConferenceonContinentalEarthquakes,Mechanism,Prediction,EmergencyManagement&Insurance(the3^rdICCE)washeldonJuly9-14,2004inBeijing,China.TheICCEhasbeenheldeverydecadesinceitwaslaunchedovertwentyyearsago.ThefirstICCE,withthetitle""""InternationalSymposiumonContinentalSeismicityandEarthquakePrediction""""(ISCSEP),hadinternationalsponsorshipandwassupportedbye.g.,UNESCOandhostedbytheSeismologicalSocietyofChina(SSC)inBeijingin1982.In1992inresponsetotheinitiativesfromtheUN'sInternationalDecadeforNaturalDisasterReduction(IDNDR),