简介：Asuiteof1.84–1.92Gametamaficdykeswithintheparagneisssuite（khondalite）oftheQuanjimassifinNWChina,hasbeenchoseninthisstudyforfurtherunderstandingthetectonicevolutionandpossiblelinkstotheglobalColumbiasupercontinent.Occurrenceandfieldrelationssuggestthattheywereformedcoevallywithapreviousstudied1.83–1.85Gametamaficdykeswarms.Whole-rockmajorandtraceelementalgeochemistrysuggestsprecursormagmaoftheamphibolitesbeinggeneratedfromavolcanicarc-relatedtectonicsettingratherthanaback-arcenvironmentwherethemetamaficdykeswarmswereemplaced.ThemetamaficdykesshowenrichmentofLREEandstronglynegativeanomaliesforTa-Nb,Zr-HfandTi,havehighSiO2（49.3wt.%–52.5wt.%）butlowMgO（6.40wt.%–7.76wt.%）contentsandMg#（Mg#=[100×（MgO/40.3）]/[MgO/40.3+FeO/71.8]）values（45.7–52.1）,suggestingevolvedprecursormagma.ThehighvaluesofLa/Ta（22.2–42.8）andLa/Nb（1.71–2.47）,mildlynegativeεNd（t）values（-2.51–0.15）,withdepletedmantlemodelages（TDM）of2.45–2.84Ga,suggestthattheirprecursormagmaswerepossiblyderivedfromasubduction-relatedfluidmetasomatizedArcheansub-continentallithosphericmantle.Thisstudyprovidesfurtherevidenceforoceanicplatesubductionprevailingbeforeoraround1.85Ga,whichconfirmsaprolongedsubduction-accretion-collisionhistoryintheNWChinawhichispossiblylinkedtotheassemblyoftheColumbiasupercontinent.

简介：TheNeotethysplaysanimportantroleinshapingtheGangdesemagmaticbelt,southernTibet.However,theinitialtimeofspreadingandsubductionoftheNeotethysremainscontentious.Inthisstudy,asuiteoflateTriassiccumulatehornblendegabbrowasidentifiedinthesouthernmarginoftheGangdesemagmaticbelt.Thegabbroexhibitscumulatestructure,withhornblendeandplagioclaseastheprimarymineralphases.Isotopicdataindicateahydrousmagmasourcederivedfromadepletedmantlewedgethathasbeenmodifiedbyslabdehydration.Geochemicaldiscriminationssuggestthatthegabbrowasformedinanintraoceanicarcsetting,withcrystallizationagesofca.220-213Ma.Hornblende,hornblendelagioclaseandilmenitethermometersrevealthatthecrystallizationtemperatureof900-750°Cforthegabbro.Hornblendeandhornblende-plagioclasegeobarometersyieldanemplacementdepthatca.14.5-19.5km.ThisgabbroconstitutesalineofevidenceforanintraoceanicarcmagmatismthatiscoevalwiththecounterpartsinthesouthernTurkey,revealinganintraoceanicsubductionsystemwithintheNeotethysfromwesttoeastintheLateTriassicandthattheoceanizationoftheNeotethyswasmuchearlierthanpreviousexpectation.

简介：Evidenceforamantleand/orbasalticcomponentinKTboundarydistalejectaisapparentlyinconsistentwithejectionfromChicxulubCratersinceitislocatedon~35kmthickcontinentalcrust(DePaoloetal.,1983;Montanarietal.,1983;HildebrandandBoynton,1988,1990).Evidenceformafic/ultramafictargetrockswasreinforcedbydiscoveryofchromites,somewithshockplanardeformationfeatures(PDF),inimpactlayersamplesfromsitesinsouthernColoradoandeasternWyoming(Bohoretal.,1990).However,untilnowitwasunclearwhetherthechromitesoriginatedwithanimpactororwithterrestrialtargetrocks.Tothisend,high-precision54Cr/52CrisotoperatiosweremeasuredonKTboundarychromitesalongwithknownterrestrialchromites.Wefindaterrestrial54Cr/52CrratioinKTboundarychromitesfromimpactlayersamplescollectedattheabovesitesoverthelastseveralyears(Fig.1).Ejectedterrestrialchromitessuggesttheimpactsampledterrestrialmaficand/orultramafictargetrocksnotknowntoexistintheChicxulubtargetarea.

简介：ObjectiveTheMiao’ershan–Yuechenglingcompositegranite,locatedinnorthernGuangxiatthewesternsectionoftheNanlingRange,isamulti-periodandmulti-stagecompositeplutonwithanexposedareaofmorethan3000km2(Fig.1).PaleozoicandProterozoicstrataareexposedaroundit,andmagmaticactivitiesmainlyoccurredduring

简介：ObjectiveThenearlyparallelN–S-trendingriftsinsouthernTibetrepresenttheE–WextensionoftheTibetPlateau.MostdatawhichconstrainedtheageoftheextensionaldeformationcomefromisotopicdatingofthedikesprobablyrelatedtotheactivityofthenearlyN–Sfaultingandmicasfromhydrothermalactivityandthelowtemperaturethermochronologyofplateauuplift.Previous

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：ThemetasedimentsintheChambaregionexperiencedthreephasesofdeformation:DF1,DF2andDF3.Foldedquartzveinsareco-foldedwiththeF2crenulationfolds.Theirgeometricandtectonicsignificanceisstudiedbymicrostructuresandshorteningadjacenttothediscretecrenulationcleavage,S2.Microstructuresoffoldedveinsegments,theirgeometricchangesandtruncationtocleavage(S2)aremainlyduetopressure-solutionphenomenaandtheestimatedvolumelossfromreconstructedveinsegmentsrangefrom16to25.5%,whichiscloselyrelatedtovolumedecrease(26%)calculatedfromthepolydeformedslatesofNorthWalesareas.

简介：暴露得好的Lijiatuo节被选择探索州的、主要生产率和海水硫酸盐在寒武纪的系列1-2期间铺平的海洋的氧化还原作用的时间的进化和控制，华南。这节由Xiaoyanxi形成(Fm)mudstones和LiuchapoFm组成。在斜坡和盆环境扔了的燧石。五个oxic缺氧的周期基于V/Sc，Th/U和瞬间，U，V，Ni和Cu的丰富因素被识别。中间上面的LiuchapoFm。并且中间的XiaoyanxiFm。在oxic-suboxic条件下面被扔，并且阶层的其余部分在缺氧的条件下面。Re/Mo比率证明oxic-suboxic在中间的XiaoyanxiFm调节。被短暂sulfidic条件伴随，并且节的其余部分是underanoxic和non-sulfidic条件。所有TOC和Ba，Ni，Cu，Zn和Cd的丰富因素表明了那在LiuchapoFm下沉和有机物(OM)的埋葬流动。在overlyingXiaoyanxiFm是比那低的。在XiaoyanxiFm的最高的下沉和OM的埋葬流动。出现在它的更低的部分；然而，在XiaoyanxiFm的最低下沉和OM的埋葬流动。出现在它的中间的部分。TOC/TS，TS和34间谍证明海水被低海洋的硫酸盐层次统治，它当免费H2S。大气的氧内容的上升可以是为联系、短暂suboxic-oxic并且将近的主要司机在中间的XiaoyanxiFm的sulfidic环境。

简介：最近，在Yaoyingtai的暴烈的煤气的水库()并且Daerhan()在Changling的构造的带()东南的Songliao的指责的消沉()盆被发现了。基于作文和同位素的价值，天然气被甲烷，C2+的低内容，和C1/C15的高内容超过0.95描绘。另外，天然气包含从20%～40%与内容包括二氧化碳的nonhydrocarbons和N2的次要的数量。与同位素的价值结合了，天然气被腐殖的kerogen和导出煤的类型产生，但是在Daerhan，天然气被油类型气体可能混合。从在暴烈的岩石中的岩性学和液体包括的测量，沥青，液体烃，和煤气的烃包括是在场的。通过在暴烈的水库的单个煤气的包括的分析，二氧化碳的内容是低的，因此水库的二氧化碳和烃气体没同时被积累。另外，在水库的沥青的次要的数量被通过biomarkers的描述从Yingcheng(842557CE)形成mudstones采购的原油的热进化形成。homogenization温度的分发与煤气的充满的舞台介绍二座山峰，有充满舞台的液体烃的山峰，和其它。在Daerhan构造的带，然而，第二座山峰是煤气的，二氧化碳混合可能充满时期。与盐水包括，油和煤气的充满时期的homogenization温度结合了从Qingshankou()形成到Nenjiang()在研究区域的形成。在收费时期期间，无机的二氧化碳的次要的数量从Sifangtai的结束充满了进陷井，而是很多的无机的二氧化碳()到Eogene，时期与结构的运动有关。

简介：

简介：

简介：M7.0Lushan地震触发了的s山崩的一个巨大的数字。印射的山崩危险性是很重要的。证据(悲痛)和逻辑回归(LR)的重量方法广泛地为LSM(印射的山崩危险性)被使用了。然而，限制仍然存在。悲痛能够估计每个因素的不同的班的影响，但是忽视在因素之间的关联。当它不能够评估不同的班的影响时，LR能在因素之中分析关系。这份报纸为LSM建议LR和悲痛的一个联合方法，利用他们的单个优点并且克服他们的限制。1289山崩的库存被使用：70%为为确认训练并且留下是选择随机的。11个山崩条件因素在模型被采用，结果用操作特征(巨鸟)曲线的接收装置被验证。结果证明LR悲痛模型比LR模型有更好的精确性，生产在有0.802成功的价值的曲线下面的一个区域并且0.791预兆，比LR模型的高(0.715成功并且0.722预兆)。悲痛和LR的联合方法能为印射的导致地震的山崩危险性提供精确性的有希望的水平，这因此被结束。

简介：

简介：CryogenianDatangpo形成在在Sturtian和Marinoan冰川期之间的间冰期的时间期间被扔。我们在东北贵州从基础Datangpo形成学习了氮同位素作文和黑页岩的瞬间的内容，华南，海洋的氧化还原作用变化和氮在间冰期的时间期间骑车一次尝试重建。象geochemical侧面一样基于岩石层位学，基础黑页岩能被划分成四间隔：间隔1有最低15N价值(+5.0)；在间隔2，15N价值在+6.4和+7.4(第一座山峰)之间变化；15在+6附近的N；并且间隔4被它的更高的15N价值，在+6.7和+7.8(第二座山峰)之间。瞬间的丰富因素的价值与上升stratigraphic趋势从56.8～2.6减少。它在Sturtian冻结成冰以后立即显示了那，在在到Yangtze站台的南部的边缘的斜坡的架之间的过渡地区上面的海洋的海水被成层，与浅海水是oxic，但是深水beingsulfidic。随后，尽管有一个oxic条件的短出现，高denitrification率在表面海水在扩展suboxic区域占优势，并且深海水仍然是缺氧或平的euxinic。

简介：ThetectonicactivitiesoccurringsincetheCenozoicinthenorthernpartoftheQinghai-TibetPlateau（theregionfromtheEastKunlunMountainstotheTanggulaMountains）wereprobablycausedbytheintenseintraplatedeformationpropagationafterthecollisionbe-tweentheIndianplateandtheEurasianplate.Theirmainexpressionsincludethesubstantialup-liftingoftheplateau,alternationofhorizontalextensionandcompressionundertheverticalgreatestprincipalstressσ1,occurrenceofrift-typevolcanicactivity,formationofthebasin-rangesystem,andsuccessiveeastwardextrusionofblocksresultingfromlarge-scalestrike-slipfaulting.Geophysicalexplorationandexperimentshaverevealedthatthereexistclose-lyalternatinghorizontalhigh-velocityandlow-velocitylayersaswellaslithosphericfaultsofaleft-lateralstrike-slipsenseinthelowerpartofthelithosphere（thelowercrustandlithosphericmantle,60-120kmdeep）.Basedonanintegratedstudyofthegeological-geophysicaldataavail-able,theauthorshaveproposedamodelofdeep-seatedmantlediapirandtheassociatedtectonophysicalprocessasthedynamicsourcefortheupliftofthenorthernpartoftheQinghai-TibetPlateau.

简介：

简介：ObjectiveTwoimportantgeologicalissueshavelongbeencontroversialintheXing–MengareaofNorthChina.ThefirstconcernsthefinalclosureofPaleo-AsianOceaninXing–Mengarea,andtheotherconcernsthefoldingandliftingoftheXing-MengTrough.ThefocusofthsesissuesistheLatePermiansedimentaryenvironment,whichis

简介：