学科分类
/ 1
20 个结果
  • 简介:调查早lycopsids,用吝啬的cladistic分析和贝叶斯的途径的发展史被介绍,与越过25taxa的33个词法人物的一个数据矩阵。产生吝啬和贝叶斯的树在树拓扑学显示出全面类似。在贝叶斯的树上,Protolepidodendrales和heterosporouslycopsids作为二个monophyletic组被认出,并且在后者以内组织Isoetalessensulato形式subclade。这拓扑学暗示一个舌状的人物的获得在lycopsids演变两次在protolepidodendralean雷克勒基亚·班克斯等,并且一次在heterosporouslycopsidclade。以前从华南的中间上面的泥盆纪报导的几lycopsid植物的种系发生的位置,有不明确的顺序的亲密关系,被cladistic分析估计;cf。薛伦戈斯塔奇斯etHao,朱伦戈斯塔奇斯等,王莫尼利斯特罗布斯et果浆,和YuguangiaHao等。在Isoetalesclade以内掉落很好,作为这份订单的最早的成员,当时王米诺斯特罗布斯和Wuxia果浆等。在heterosporouslycopsids的基础部分以内被嵌套。贝叶斯的分析是在系统的研究的一条很有用的途径并且能在分析数据也设置的paleobotanical被使用。

  • 标签: 系统发育分析 贝叶斯方法 泥盆纪 分支系统 拓扑结构 贝叶斯分析
  • 简介:Thegrowthprocess,palaeoecologicalfeaturesandthefunctionoforganismsinreef-buildingoftheJukoupubioherminHunanarediscussedindetail.Thebiohermisdividedinto10microfacies.Organismsareveryabundantinthereef.Thirty-twogeneraBelongingto7phylahavebeenrecognized.Theymakeup5communitiescomposedmainlyofstromatopoids,Coralsandalgae,eachofwhichhasitsownsalientecologicalfeatures.Ananalysisofallcommunitiesshowsthattheorganicfunctionsareverycomplex.Thesameorganismsmaypossessdiversefunctionssimultaneouslyasthereefgrowthentersthelatestage.Thegrowthprocessofthereefmayinvolvefivestages’(l)biostromestage,(2)stabilizationstage,(3)frame-typereef-buildingstage,(4)bindingandcovering-typereef-buildingstage,and(5)baffle-typereef-buildingstage.

  • 标签: HUNAN Province MIDDLE DEVONIAN REEF COMMUNITY
  • 简介:<正>TheDevonianhydrotyermalsedimentationandmineralizationarewidespreadandtypicalinMaizi、KelangandChonghuerbasinsofsouthernAltaymargin,andhavetheirrespectivesignsinoccurrence,fabricandgeochemistry.Hydr)thermalsedimentaryrocksmainlyoccurintheintermittentperiodbetweenvolcanicsub(?)ycles.Theyarethin-midium-bedded,lenticularandbasicallyuniformtotheoccurrencesoftheoverlyingandunderlyingstrata.Theclassificationofthehydrothermalsedimentaryrocksisproposedbasedonthemineralcompositions.Thedetaileddescriptionsaregiventothefivetypesofhydrothermalsedimentaryrocks:silicates,feldspar-richrocks,

  • 标签:
  • 简介:TheDevoniansuccessioninSouthChinaiswell-knownforitscompletedevelopment,vari-fiedsedimentarytypes,remarkablelithofaciesvariationandabundantmineralresources.TheSouthChinaplatewasformedbythecollisionandcollageoftheYangtzeplateandtheCathaysianplate.ThecollisionbeganapproximatelyattheJinningianstageandthecollagewasnotfinalizeduntiltheGuangxianmovement.ItwasontheSouthChinaplatewithasomewhatdifferentnatureofthebasementthattheDevoniandepositionformed.

  • 标签: DEVONIAN features of SEDIMENTARY BASINS MINERALIZATION
  • 简介:有增加极化的一个完全的词法坡度的一组radiolarlan石块在西南的Tianshan从上面的泥盆纪继任被报导,中国,明确地重要过渡raophotypes,Pylentonematransitorumsp。nov,Archocyrtium中等sp。nov。并且Quadrapesustransitivussp。nov,被发现。基于新过渡放散虫类的各类动物石块在形态学比到entactinids(spumellarians)更非常类似于到pylentonemids(cyrtoidnassellarians)的事实,他们被分配topylentonemids。两个的Pylentonemids份额字符Nassellaria(例如,hornedcephalis,有pylome的基础洞)并且Spumellaria(例如,trabecular骨针的系统),并且他们因此具有进化意义。到nassellarians的从spumellarians的进化趋势被描绘由(1)内部骨针:从简单trabecular骨针复杂化部件(一;lr,ll;D;V;Lr,李;MB);(2)放散虫类的各类动物的极化由于脊骨的rearrangment测试,从对轴的对称光线;(3)一个基础洞的渐渐的形成(孔,pylome,orpodome);并且从pseudopylome的转变,有外部壳上的狭窄的边缘的priniativepylome,到有一面狭窄的、提高的Impermite墙的真pylomerimmed。

  • 标签: 放射虫 泥盆纪 化石 偏震
  • 简介:BiostratigraphicaldataindicatethatintheneriticfaciesareasofSouthChina,theDevonian-Carboniferousboundary(DCB),matchingtheboundarybetweenconodontSiphonodellapraesulcatazoneandS.sulcatazone,shouldbedrawnbetweenrugosecoralCystophrentiszoneandPseudouralinazone,i.e.theCystophrentis\Pseudouralinainterval-zone.ThetopofthesealevelfalleventbedneartheDCBislowerthantheboundarybetweenS.praesulcataandS.sulcatazones,buthigherthanthetopoftheCystophrentiszone.SequencestratigraphicalstudyshowsthatthesealevelfalleventbedneartheDCBconstitutestheshelfmarginsystemtract(SMST)ofadepositionalsequence(SQ1)inbothneriticandpelagicfaciesareas.ThetopsurfacesofSMSTofSQ1isslightlylowerthanthebaseofS.sulcatazoneinthepelagicfaciesareas,InneriticfaciesareasofSouthChina,therefore,theDevonian-CarboniferousboundaryismarkedbythemostdistincttransgressivesurfacewithintheCystophrentis\Pseudoura

  • 标签: BOUNDARY DEVONIAN and CARBONIFEROUS integrated STRATIGRAPHY
  • 简介:CalcareousAlgaefromNortheasternBrilonReefComplexofMiddleandUpperDevonianinEasternSauerland,Germany¥HongTianqiu(DepartmentofRe...

  • 标签: CALCAREOUS ALGAE REEF COMPLEX factes zone
  • 简介:DuringthelasttwodecadesresearchontheDevonianperiodwaspartofsomesuccessfulIGCPprojects,suchasIGCP216""""""""GlobalbiologicaleventsinEarthhistory""""""""(ledbyO.H.Walliser),IGCP335""""""""Bioticrecoveriesfrommassextinctions""""""""(ledbyD.H.ErwinandE.G.Kauffman),andIGCP421""""""""NorthGondwananMid-Palaeozoicbioevent/biogeographypatternsinrelationtocrustaldynamics""""""""(ledbyR.FeistandJ.A.Talent).

  • 标签: 泥盆纪 海陆交互作用 生态系统 气候变化
  • 简介:Theprocess-faciestypesoftheDevonianvolcanicsedimentarysuccessionsinnorthernXinjiangincludeexplosivefacies,effusivefacies,pyroclastic-calcareous-terrigenoustempestitefacies,andcoarse~-,medium~-andfine-grainedpyroclasticturbiditefacies,volcaniceruptiontsunamitefacies,syndepositionalandsoft-deformedseismitefacies,sandyandsilt-muddycontouritefacies.Thispaperpresentstheircharacteristicsanddiagnosticindicators,anddiscussesthetemporalandspatialstructuresofboththeprocess-faciesandtheenvironment-faciesoftheZhifangsection,eastJunggar,andtheMountSarburtisection,westJunggar,andtheirrelationtoplatetectonism.Theauthorholdsthatthefaciesanalysisdominatedbyprocess-faciesisthefaciesanalysis’nucleusinanorogenicbeltandactivecontinentalmargin.

  • 标签: process FACIES environment FACIES volcanic-sedimentary SUCCESSION
  • 简介:Tourmalineiswidespreadinthehoststrataofstrata-boundbasemetalsulphidedepositsintheDevonianmetallogenicdeistrictaroundShanyang-ZhashuiineasternQinling,Asamemberoftheschorl-draviteseries,thetourmalineischaracterizedbyMg>FeandNa>Ca,showingapparentchemicalzonationwhichrecordsthegeochemistryduringitsformationandsubsequentregionalmetamorphismandhydrothermaloverprint.Theclosesimilarityinchemicalandisotopicconstitutionsbetweenthetourmalineofthemainmetallogenicepochinthisdistrict[FeO/(FeO_MgO)=0.34-0.39andδ^11B=-7.6‰--8.8‰]andthoserelatedtomassivesulphidedepositstypicalofsubmarine(exhalative)hydrothermalsedimentation

  • 标签:
  • 简介:InNanlin,alargenumberofPb-ZndcpositsandSbdcpositsincludingtheworldfamousgiantSbdepositcalledXikuangshanmineareDevoniancarbonaterock-liosted,Ourjnvcstigationsuggcststhatmanyofthcscdcpositswercmineraljzcdbyorc-bcaringgroundwater.IMajorProoIsofOre-BearingGroundwatcrMincralisationTherearcmanyproofiofgro

  • 标签: