简介:ThisstudyfocusesonthebasementstructureoftheParanáBasininSouthAmerica,basedongeologicalandgeophysicaldata.ItisalargeintracratonicbasinformedfromtheLateOrdovicianuntiltheCretaceous,whenasequenceofcontinentalfloodbasaltseruptionscoveredtheentirebasin,precedingthebreak-upofWesternGondwana.Isostaticmodelingwasappliedtolargegravitysurveyscomprisingmorethan12,000gravitystations.TheresidualBougueranomalypattern,representingthecrustalcontributionofthecrystallinebasement,aswellasthesedimentaryandvolcaniclayersofthebasin,revealssimilaritiesbetweenthebasementgravitysignatureandtheexposedrock.ThestresspatternsoftheLateOrdovicianandCretaceoustectoniceventspresentageographicallycoincidentmaximum,andthecorrelationbetweengravityhighsandthemainattenuation(betafactor)suggeststhepresenceofsomepreexistentsuturezones.TheresultantmosaicofgravityblocksandthelocationofmajorfaultsgivesupporttothepresenceofanimportantProterozoiccratonicfeature,herereferredtoasParanapanemablock.
简介:TheNorthChinablock,thewesternportionoftheSino-KoreanCraton,isroundedbyYanshanianinthenorthandQinling-Dabieorogenicbeltsinthesouth.Thewidespreaddevelopmentofextensionalbasinsinthisblockindicateshorizontalextensionorcontinuedthinningofapreviouselythickened,trnstablelithospherethroughouttheMesozoic.Inthispaper,weattempttosimulatenumericallythegeodynamicalprocessofthebasinformationbyusingthemountain-basinevolutionsystem.WeassumethattheformationofnumeroussedimentarybasinsintheNorthChinablockistheresultofthecrustalextension,whichdestructsrapidlythepreviouslythickenedcrust.
简介:ThenorthernmarginoftheAlxablockisthejunctionofatectonicunits.Fourfirst-ordertectonicunitsaredistinguished:1.theYaganstructuralzonecharacteristicofanimmatureislandarc;2.theZhusileng-Hangwulastructuralzone,whichwasapassivecontinentalmarginintheEarlyPalaeozoicandwastransformedintoanactivecontinentalmarginintheLatePalaeozoic;3.theShalazhastructuralzonecharacteristicofamatureislandarc;4.theNuru-Langshanstructuralzone,whichwasaProterozoicorogenicbeltandlaterevolvedintoanextensionaltranstionalcrustinthePalaeozoic.Theabove-mentionedtectonicunitsdifferremarkablyinsedimentaryformations,magmaticrockassociations,metamorphismandgeochemistryandareboundedbyfaultsbetweenoneanother.
简介:MultistagesuperimposeddeformationhasbeendiscussedsystematicallybasedontheprogressofthestratigraphicsequencesofthenortheasternmarginofYangtzeBlock.Thenew-discoveredfirststagedeformationofthosesequencesoccurredfromthemiddleTriassictotheendofearlyJurassictogetherwithdevelopmentofregionalfolding,whichwasresultedfromthedeepdetachmentshearingtendingtowardNW-WNW.Thefoldsdiptoeastandfalldowntowardwest,andweresuperimposedbythemainstagefolding.Thereafter,aseriesoffoldsweredevelopedwithaxestrendingtowardnortheast.Consequentlynormalfoldsoccurredonthenormallimbswhileoverturnedfoldontheoverturnedlimbsduringthefirststagefolding.ThedetachmentorthrustwasformedfromlateJurassictoearlyCretaceous.DuetotheupliftingofDabieandtheWannanMountainsinthenorthandsouthsides,thebi-directionalthrustingbeltwasformedbygravityflowingfromtheMountainstowardthecenterofthebasinalongthenorthsideofXuanchengandsouthsideofGuichi.Thedeformationgeodynamicswasdiscussedsimplybasedonthenewlyrecognizedinformationaboutthetectonicevolution.
简介:INTRODUCTIONThepaleocontinentalmargins,characterizedbyactivein-teractionbetweenearthcrustandmantle,complicatedtecton-icmoveme...
简介:源自陆地的siliciclastic的一个序列在Baxiandun外面摇庄稼,Qingdao,在在诺思中国之间的中生代collisional边界附近,块(网络控制块)和华南堵住(SCB)。这些低档变形了siliciclastic岩石被greywacke与页岩统治,manganiferous有细密纹理的沙岩,arkose和集团企业层。关于这些岩石的形成有二基本解释。一个人认为这个序列在网络控制块以内被形成,并且是白垩纪Laiyang组和Qingshan组的部分河的外形和暴烈的碎片外形出现在山东地区性的地质的地图上。另一条意见建议这些岩石表示在斜坡和盆外形的混浊depositional系统主要在奥陶纪被扔。重要地基于地观察,petrological分析,和大多数,在这的geochemical结果学习,在Baxiandun节的沉积阶层主要由siltstone,沙岩和mudstone岩性学组成。他们被深海的碎片和混浊存款在一个湖的斜坡和底统治。在Baxiandun节岩石标明日期的U-Pb由岩屑形成的锆石显示来源岩石是很复杂的,他们的年龄被改变从对早白垩纪太古代。源自陆地的岩屑的最年轻的年龄能代表沉积阶层的年龄。因此,我们推断沉积岩石属于早白垩纪深海的湖的沉积序列并且从SuluUHPorogen和华南块边缘的侵蚀有多重来源origined。
简介:<正>Potashisoneofthelong-termscaredepositsinChina,andpotashprospectinghaslongbeenlistedasakeybrainstormprojectforournationandgeologicalprospectingunits.TherehavebeenconsiderablestudiesinsearchforpotashdepositsintheKuqadepressionoftheTarimbasin(Jacksonetal.,1991;Gemmeretal.,2004;Vendeville,2005;VendevilleandJackson,1992a,1992b),
简介:Hutubi()井块DX12的河水库是在构造背景下面的一座lithologic烃水库。在这个区域的主要的含有石油的沙身体是薄的并且有一个差的横向的连接。因为油水关系的复杂性,油水库介绍一个低抵抗力特征,它把大困难带到烃水库鉴定。这篇文章开发能满足很好记载评估的低抵抗力水库的要求的井木头解释的一个有效方法。作者联合油水库地质学特征,记载曲线特征的油井和为低抵抗力分析原因的化学分析数据,然后建立适当水库参数解释模型,它使用不同浸透计算方法根据不同的代。当泥土内容是超过5%时,我们选择W-S双水模型;当页岩内容是超过13%时,我们使用Schlumberger公式;当页岩内容不太当时是13%时,我们使用高射炮公式。低抵抗力水库的好记载评估方法被被渗透,孔,毛孔结构的系数和页岩建立的无法缩减的水浸透公式改进了记载方法的内容,烃水库识别图表,和非抵抗力(重复形成测试(RFT);模块化的动态测试(MDT),等等)。为记载综合解释的井的这安排的巧合率在井块DX12是82.6%。它是为低抵抗力井木头解释的一个强大的方向。
简介:ObjectiveTheEmeishanlargeigneousprovince(ELIP)inSWChinaistheonlyonelargeigneousprovinceinChinarecognizedbyinternationalgeologists.PreviousstudiesofELIPoverpasttwodecadesindicatethattheELIPage,duration,scaleandgenerationmechanismarestillcontroversial.Amongthosescientifictopics,some
简介:DuringtheEarly-MiddleProterozoicera,threemajorlithostratigraphicunitassociations,namelyHekou-Dahongshan,Dongchuan,andKunyang-HuiliGroups,wereestablishedforthemetamorphosedvolcanicsedimentaryrocksexposedinthesouthwesternYangtzeBlock(SWYB).Theintegrationofpetrology,geochemistryandgeochronologyconstrainstectonicframeworkandevolutionoftheSWYB,inwhichfoursetsofSHRIMPU-PbzirconageswereobtainedfromthevolcanicrocksinterbeddedwithintheMiddleProterozoicsuccessions:1800-1600Ma,1600-1300Ma,1300-1100Ma,and1100-1000Ma.Majorandtraceelementalanalysisindicatethatfourkeytectonicevolutionarystages,eachcoincidingwiththeaboveradiometricageset,oftheSWYBduringtheEarly-MiddleMesoproterozoic.TheSWYBwascharacterizedbyaneast-westerlytrendingriftintheHekou,Dongshan,andDongchuanareas,andseparatebasin-formingeventsduring1800-1600Maarid1600-1300Ma,respectively.IntheSWYB,anintracontinentalriftbasinandariftbasinoccurredintheCaiziyuan-MatangandLaowushanareas,respectivelyin1300-1100Maago.During1100-1000Ma,theSWYBwascharacterizedbytheclosureoftheCaiziyuan-Matangrift-oceanbasin,collisionbetweentheHuiliBlocksandKunyangBlocks,andpresenceofvolcanicaresintheTianbaoshanandFulingpenareas.Accordingly,theSWYBrepresentsanewbasinthatrecordstherelativelycompleteassemblyprocessoftheRodinaduringtheEarly-MiddleMesoproterozoicera.
简介:在华南的Dajiangbian形成是统治siliciclastic的沉积继任,低档变态在卡赛西亚·布洛克的西方的边缘上扔了,并且被glaciogenicdiamictite(Sizhoushan形成)盖住。Sizhoushanglaciogenic阶层能被归因于Jiangkou冰川(Sturtian冰川)他们在华南与Jiangkou阶层分享stratigraphic和lithological类似的事件。在整个Dajiangbian形成的上面的部分的一些碳酸盐,燧石和页岩单位为碳酸盐碳同位素被取样(13Ccarb)和器官的碳同位素(13Corg)分析。geochemical的一个范围索引包括氧同位素(18O)并且Mn/Sr(Fe/Sr)比率建议主要的碳同位素价值在上面的Dajiangbian形成被保存。上面的Dajiangbian形成表演13C向上减少向的-0.1,的carb到-5.4。我们建议否定13在Sizhoushandiamictite下面的C旅行是有Pre-SturtianIslay13Ccarb异例并且与全球Neoproterozoic同位素地层学允许关联。我们发现碳酸盐和上面的Dajiangbian形成的器官的碳同位素数据被联合,与13Ccarb-13C在多重大陆上观察的org模式。