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37 个结果
  • 简介:Carbothermalreductionandnitridation(CRN)ofzircon(ZrSiO4)permitsobtainingdifferentcompositesofoxidesandnitridessuchasZrO2-Si2N2OandZrN-Si3N4.Theeffectsoftechnologicalparameters(carbonsource,reactiontemperature,andcarboncontent)onthereactionrateandproductphasecompositionofCRNofzirconwereinvestigatedbyTGAandXRD.Theresultsshowthat:(1)carbonsourceisanimportantfactorforarapidreaction,andactivatedcarbonischosenasthecarbonsourceconsideringtheexpectproductsandreactionrate;(2)reactiontemperaturehasvitaleffectonreactionrateandproduct.Incaseofcarboncontentabove20%,thezirconphaseandm-ZrO2phasedecreasewithincreasingtemperature,whiletheZr7N8O4phaseincreasesfirstlyandthendecreases,andtheZrNphaseincreasescontinually;(3)differentcarboncontentsresultindifferentreactionproducts.Thehigherthecarboncontent,thelowerthestartingtemperaturefortheCRNofzircon.

  • 标签: 碳热还原氮化 工艺参数 锆石 反应温度 SI2N2O 反应速率
  • 简介:1IntroductionNanshankengtungsten-tinpolymetallicmine,whichislocatedintheeasternNanlingmetallogenicbelt,isnewlydiscoveredbygeologicalinvestigationandevaluationwithprospectingpotential(Xiaoet

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  • 简介:GlobalabruptclimatechangefromMarinoansnowballEarthtogreenhouseEarth,recordedascapcar-bonateoverlainondiamictite,hadshedthefirstlightonCambrianbio-radiation.Themostdocumentedcapcar-bonatesectionsaretypicalwithcomprehensiveδ13Cneg-ativevaluesandubiquitoussedimentarystructures,suchastepee-like,sheet-cracketc.,whichareassociatedwithsuccessiveglacialeustaticvariationcausedbyisostaticreboundinshallow-waterfacies.Herewereportadeep-waterbasinalcapcarbonatesectionwithstrongnegativeδ13CvaluesinthesouthernmarginoftheQinlingOrogen,Heyu,ChengkouCounty,ChongqinginChina,whichconsistsofmassivedolostonewithabundantcarbonaceouslaminae.However,itlacksthesedimentarystructureasmentionedaboveandisoverlainbythin-beddedsiliciousshalesandcherts.AK-bentonitebedwasdiscoveredwithinthebaseofcapcarbonates,about0.7mabovethetopoftheMarinoandiamictite.Magmaticzirconsthatweresep-aratedfromtheK-bentonitebedyieldaSIMSconcordiaU-Pbageof634.14-1.9Ma(lσ,MSWDcE=0.31,ProbabilityCE=1.000,n-=20).TheageisingoodagreementwithpreviouslyreportedTIMSU-PbagesfortheterminationofMarinoanglaciationandprovidesageochronologicalconstraintfortheEdiacaransuccessionsintheQinlingOrogen.

  • 标签: NEOPROTEROZOIC Cap DOLOSTONE K-BENTONITE U-Pb age
  • 简介:Quanji()山岳位于西北中国,它是被解释一微大陆那由变形地下室和稳定的盖子阶层组成。在中国有在Quanji山岳和主要cratons之间的基因关系的一些争吵。在这研究,我们在situ锆石U-Pb和Hf获得了Yingfeng的同位素的作文()从由LA-MC-ICP-MS的申请的西北Quanji山岳的rapakivi花岗石技术。二十个U-Pb年龄大小点一致或近一致,并且他们的加权的吝啬的207Pb/206Pb年龄是1个793.9ene大陆人更低的外壳。我们测量磁性的参数(危险性和磁性的磁滞现象参数例如浸透磁化Js,浸透等温的残余的磁化Jrs,和内在的coercivityHc)十一,Hannuoba从太古代的Huaian地面降低外壳的捕虏体和九地面granulites。结果显示一般水准珍视,太古代的granulites的Js和Jrs是4122洠条敮楴?業敮慲潬祧愠摮瀠瑥潲潬祧;衜?衜?

  • 标签: 锆石Hf同位素 环斑花岗岩 地壳生长 地块 GA 中国西北地区
  • 简介:在中国的江苏海岸定位的光线的沙山脉系统(RSRS)为它的特殊结构和潜在的陆地资源在它形成的起源和技工上吸引许多注意。由于复杂水动力学状况,江苏RSRS是一热在它的潜在的来源,长江或黄河上辩论了吗?我们在夏天从现代黄河河口沿着Bohai海和黄海的西方海岸从表面沉积收集了十件沙样品到长江河口,2013。样品被由岩屑形成的锆石年龄的方法为RSRS沉积的来源鉴定分析。样品的由岩屑形成的锆石谷物的U-Pb年龄系列从新生代显示出一个宽范围到与几座年龄山峰晚太古代。比较在长江和黄河之间的年龄系列,由岩屑形成的锆石有更年轻的年龄(<100妈)在长江的组。江苏沿海的RSRS沉积的这些年龄分发类似于长江的,但是与黄河不同。邻近旧黄河三角洲的定位的样品显示出更宽范围的年龄分发,暗示来自两条河的加重的起源。把调查结果基于这些与普通意见相反,江苏RSRS的主要沉积来源是长江,而非黄河,这被建议。由牵连,应该有海洋的水流和潮汐的运动的水动力学力学的证据。这个方面在未来研究等候证实。

  • 标签: 黄海 江苏海岸 光线的沙山脉 锆石地球年代学 沉积起源
  • 简介:在结晶化以后沿着Yangtzecraton和他们的变形历史的西方边缘澄清变形侵入的关系,石油化学并且踪迹元素geochemical人物,标明日期的锆石虾U-Pb,和化学药品从在Kangding的Neoproterozoic变形侵入的共存的角闪石和斜长石的作文(),四川()省,和Yuanmou(),云南()省,被学习。与以前的出版数据结合了,在Yangtzecraton的西方边缘的Kangding花岗石的plutons和Yuanmou建筑群通常在一样的句号形成了,这被显示。在700妈的变形事件广泛地存在,至少在四川从Kangding区域盖住到Eshan()在中央云南的区域。而且,角闪岩外形可以代表山峰地区性的变形状况。

  • 标签: 锆石SHRIMP 康定地区 新元古代 变质岩 元谋 四川
  • 简介:Henglingguan和Beiyu变形granitoids,在Zhongtiaoshan前寒武纪的建筑群的西北分布式,包括trondhjemites和计算碱的monzogranites,与太古代的ZhaiziTTG片麻岩显示恼人的接触。并且Beiyumetamorphicgranitoids主要由trondhjemites组成,在Hujiayu背斜褶层的核心分布式。分别地,标明日期加权平均值~(207)Pb/~(206)Pb变老的数据表演的新虾锆石U-Pb是为Henglingguan变形计算碱的monzogranites和Beiyumetamorphictrondhjemites的2435.9Maand2477妈并且揭示600妈继承了的~2在magmatic锆石的核心。Whole-rockgeochemical数据显示那所有Henglingguan和Beiyu变形trondhjemitesandcalc碱的monzogranites属于遇见了铝土的中等钾、高钾的calc-alkalineseries。这些岩石被相对高的全部的碱内容描绘(Na_2O+K_2O,在to9.08%上面),弄空的Nb,Ta,P和Ti,和衰退权利的REE模式与对高LREEs/HREEsfractionation中等(吝啬的比率(La/Yb)_n=25)。在多元素蜘蛛图的Henglingguan和Beiyumetamorphictrondhjemites显示negativeRb,Th和K异例由原始披风使正常化。Sm-Nd同位素的数据表明这些granitoids有起始的ε_(Nd)到+2.4和Nd的(t)=-1.2弄空T_(MD)=的披风模型年龄2622马马。所有thesegeochemical特征显示这些granitoids在一条大陆边缘的弧被形成,并且trondhjemites主要从少年的部分融化发源玄武岩的材料并且然而,Henglingguan变形计算碱的monzogranites源于在一条大陆边缘的弧下面在古老的外壳中材料再循环。花岗石的岩浆在他们的形成期间经历了污染和分离结晶。

  • 标签: 地球化学 地质年代学 花岗岩 山西 变质岩
  • 简介:ThispaperdealswiththeformingageoftheShuiquangougold-bearingalkalinerockwiththehelpofthesinglezirconPb-evaporationmethod.Theapparentage(16-7-1667Ma)gotformcrystallinezircongraindomains,wherethereexistsanalmostenclosedsystem,isingoodagreementwithzirconU-Pbconventionalupperinterceptage(1718Ma),suggestingthattheShuiquangougold-bearingalkalirockintrudedat1600-1700Maago.

  • 标签: 锆石年龄 张家口地区 河北 碱性岩
  • 简介:Geza岛弧是一个著名矿化作用集中区域,在西藏的高原的东方边缘的Sanjiang领域的部分。在最近的年里,几迟了的Yanshanian花岗石的侵入和联系存款在这个区域被发现了,在桃花源,区域是其一最大Laba铝存款。以前的研究建议预定Laba矿化作用是85±2妈。然而,granodioritic斑岩的年龄仍然保持未知。在这研究,从忍受辉钼矿的granodioritic斑岩的三件样品锆石标明日期的LA-ICP-MSU-Pb与85.00±的产生日期一起被进行了0.23妈(MSWD=0.58),85.28±0.28妈(MSWD=1.12),并且84.83±0.26妈(MSWD=0.79)分别地,显示这些granodioritic斑岩在∼85附近在迟了的Yanshanian形成了妈。与矿化作用的地质的特征结合了,时间地,Laba存款遗传上空间地与granodioritic斑岩被联系。另外,Laba存款的年龄与另外的迟了的Yanshanian侵入和矿化作用一致,建议矿化作用可能在在迟了的白垩纪期间的intra板extensional环境下面被产生。

  • 标签: 锆石U-Pb年龄 花岗闪长斑岩 中国西南地区 钼矿床 地质意义 LA-ICP-MS
  • 简介:TheYangshangolddepositisasuper-largefine-graineddisseminatedgolddepositlocatedinsouthernGansuProvince.ItsmetallogenicagehasbeendeterminedbyusingthecathodoluminescenceimageandionprobeU-Pbdatingtechniques.Itisfoundthatzirconsfromquartzveinletofthefine-graineddisseminatedgoldoreshowcharactersofmagmaticoriginwithprismidiomorphism,oscillatoryzoninganddominantTh/Uratiosof0.5-1.5.Threemainpopulationsofzirconsareobtained,givingaverage206pb/238Uagesof197.6±1.7Ma,126.9±3.2Maand51.2±l.3Marespectively.ThefirstagecorrespondstotheK-Arageoftheplagiogranitedike,whilethelattertwoagesindicatethatburiedCretaceousandTertiaryintrusivesexistintheorefield,suggestingthattheYangshangolddepositwasgeneticallyrelatedtothethreemagmatichydrothermalactivities.Bycontrast,zirconsfromcoarsegold-bearingquartzveinintheminingareaaremucholderthanthehostrock,indicatingthattheveinwasformedearlierandwasnotcontaminatedbylatermagmaticfluids.ItisconcludedthatthecouplingofmultiperiodichydrothermalactivitiesintheminingareahascontributedalottomineralizationoftheYangshangolddeposit.

  • 标签: 散布型金矿 石英矿脉 SHRIMP 甘肃 阴极发光图像
  • 简介:TheXishaBlockisaminoroneintheSouthChinaSeaandanimportanttectonicunitinthenorthwesternpartoftheregion.ZirconSHRIMPU-PbagesforthreevolcanicintrusivecoresamplesfromXike-1,anexploratorywellpenetratingthebiohermsoftheXishaIslands.ThecoresamplesarefromtheMiocenereefcarbonatebedrockandarerecognizedasdark-graybiotite-hornblendegabbro,grayfne-grainedbiotitediorite,andgrayfine-grainedgranite,respectively.Zirconcathodoluminescence(CL)imagesandtraceTh,UandPbcompositionsofthezirconsshowthattheserocksareofvolcanicintrusiveorigin.ZirconSHRIMPU-Pbdatingyieldedsixgroupsofages,rangingfrom2451-1857MatoearlyCretaceous,whichindicatethattheformationandevolutionoftheXishaBlockwasaffectedbytheevolutionandclosureofNeotethysOcean,probablywithinitseasternextensionintoSouthChinaSea.Bothold,deepsourcedmaterial,includingfragmentsfromRodinasupercontinent,andrecentmantle-derivedmagmaproductscontributedtotheemergenceandformationoftheXishablock.TheSHRIMPU-PbresultsalsoprovedthatthisprocessdifferedfromthatoftheKontummassif,theHainanBlock,andtheSouthChinaBlock,butissimilartothatoftheNanshaandZhongshablocks.TheprocesswasassociatedwiththeeffectsofYanshanianmagmatisminducedbysubductionmechanismsofthePaleo-PacificPlateorthereworkingofthemultiplemagmatismssincetheEarlytomid-Yanshanian,possiblyjointlyexperiencedbytheXisha-Zhongsha-NanshaBlock.

  • 标签: GEOCHRONOLOGY Volcamc INTRUSIVE rocks ZIRCON SHRIMP
  • 简介:ObjectiveThepotassicandultrapotassicrocksrelatingtotheIndia-EurasiacollisionandcontinualplateconvergencearewidelydistributedintheLhasaterrane.TheserocksareveryimportanttounderstandthedeepprocessesoftheIndia-EurasiacollisionandtheupliftandevolutionoftheTibetanPlateau.Althoughhigh-potassicvolcanicrocksarealsoexposedinthewesternLhasaterrane,theirformation

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  • 简介:ThereportednewU-Pbagebysensitivehigh-resolutionionmicroprobe(SHRIMPⅡ)onzirconwasobtainedfromatuffsampleatthebasalDoushantuoFormationintheJiuqunaosection,whichsituatedatthewesternlimboftheHuanglinganticlineintheYangtzeGorgesinZigui,Hubei,SouthChina.Eighteenspotsofzirconswereanalyzedandtheyformtwoclusters:oneincludesthreespots,withaninheritedageof784+15Ma(MSWD=0.05);theotherconsistsof15spotsandgivesaweightedmean^206pb/^238Uageof628.3±5.8Ma(MSWD=0.86).ItisthefirstSHRIMPU-PbzirconageobtainednearlythebaseoftheDoushantuoFormationofEdiacaranandrepresentsamaximumageoftheDoushantuoFormationItalsoformsanageconstraintontheupperlimitageoftheNantuo(Marinoantype)glaciation.

  • 标签: 中国南部 扬子江峡谷 同位素年代测定 冰川作用