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简介：FourteenisolateddrownedreefshavebeenidentifiedaroundtheXishaUpliftbymultibeamandseismicdata.Thedrowningprocessesofthesereefscanbedividedintothreedifferentstages,whichcorrespondtothreedifferentacceleratedtectonicsubsidenceperiods.ThedrowningoftheXishareefsistheresultofthecombinedactionoftectonicsubsidenceandsealevelfluctuations,andthetectonicsubsidenceratehadtoremainabove0.2mmyr-1foralongtime.ThreeabruptacceleratedtectonicsubsidenceeventsthatoccurredinthelateMiocene,PlioceneandearlyQuaternaryintheXishaUpliftwerecloselyrelatedtothethermalsubsidenceprocessesafterthreestagesofpost-riftingmagmatism.ThemagmatismofthemiddleMioceneandthefollowingthermalsubsidenceresultedinthedrowningofreefsinthenorthwesternXishauplift(ZoneA).DuringtheearlyPliocene,massivemagmaticintrusionsandvolcaniceruptionsoccurredintheXishaUplift.Then,thesubsequentthermalsubsidencestartedthedrowningprocessofreefsinthenortheasternandwesternregionsoftheXishaUplift(ZoneBandC).DuringtheearlyQuaternary,large-scalemagmatismalsooccurredintheXishaUplift.Thesubsequentthermalsubsidenceresultedinanewrapidtectonicsubsidence,whichcausedthereefsinthesouthernandsoutheasternregionsoftheXishaUplifttodrown(ZoneDandE).

简介：珊焊是一个sensitive-to-environment建筑群水兵生态系统。珊瑚的Theecosystem富于生物多样性。遥感为分类珊焊提供一个强大的工具并且是大多数费用-有效途径为大-规模礁石调查。DongshaAtoll，有10m的平均深度的超过300km~2，在华南海的北大陆人边缘被定位。它被在最近的十年期间的破坏钓鱼滥用了。三卫星形象(Quickbird2，ETM+和SPOT5)被用来评估能力ofSPOT5形象提供为在那里分类珊焊的当前的分发是有用的数据。在处理的数据期间，无指导的分类功能为ETM+和SPOT5数据被采用，当监督分类方法被用于Quickbird2时。班是()合并了进珊焊，然后将被vectorization，简化，和拓扑的分析操作。有比有3x3pixels在的察觉限制的100m大的1331珊焊多-Quickbird2的乐队数据，它作为比较基线被拿。从SPOT5和ETM图象提取的Theresults比从theQuickbird2图象的那些是在数字和区域的更少，而从SPOT5数据的结果由于它的更高的分辨率比在淤泥的泻湖的ETM数据的那些好。因为它的差的穿入能力，SPOT5x乐队2没能与ETM数据相比在环礁内区分深底层。仅仅看到x乐队1cannot被用来把珊焊区分开来与沙底部。多合并SPOT5-有SPOT5平底锅的空间分辨率的乐队数据-数据并且指ETM形象被期望提供一颗最佳的卫星-为珊焊印射的基于的途径。

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简介：AdetailedsurveyofthereefsintheNanshaIslands’seathatareofstrategicimportanceisconducivetotheirfuturedevelopment.Inthisstudy,atotalof50Landsat8operationallandimager(OLI)imageswereusedtoanalyzethegeologicalfeaturesandspectralcharacteristicsoftheNanshareefs.Theexposedislands/sandbanks,reefflatsandsub-tidalreefswereidentifiedwiththenear-infraredband,theredandgreenbands,andtheblueband,respectively.BasedontherelationshipsamongvariouscharacteristicsandbandsillustratedintheOLIimages,themaximumbetween-clustervariancethresholdalgorithm(OTSUmethod)andthemathematicalmorphologywereemployedtoextractcharacteristicparametersofthespatialgeometryofthereefsfromtoptobottom,whichweresubsequentlyoperatedbyaseriesofpost-processingmethodssuchasvectorization,simplificationandtopologicalanalysis.Amongthe132standalonereefsand16atollsthatareidentifiedinthestudy,fourreefshaveyettobenamedintheStandardNamesofVariousIslandsintheSouthChinaSeaandthewebsiteNanshaIslandsOnline(http://www.nansha.org/).Another24onesareexposedtotheatmosphereevenduringhightides.TaipingIslandwithanareaof0.57km~2representsthelargestexposedgeologicalfeature.Thisstudydemonstratedtheapplicabilityofmedium-resolutionsatelliteimagestoderivethecoralreefinformationeffectivelyandthusprovidedinformationfortherelateddepartmentsthatareresponsibletomanagethecoast.Animprovedresolutionofmultispectralbandswiththepanchromaticbandinhigherspatialresolution(15mforOLIimage)isexpectedtoprovideanoptimumsatellitebasedapproachtomapmarinehabitats.

简介：Tarim盆在含碳的时期期间是craton块。除了它的开西南(SWW)加深盆边缘，盆的中央部分被包围由北、东方、南部高举。在盆的大多数部分，有岩石把Biocalcarenite成员，标准石灰石成员和Xiaohaizi形成称为的碳酸盐的三层。今日的Maigeti斜坡，在盆的西南的区域定位了，曾经是到clinoform的paleogeographic碳酸盐站台边缘。在区域的地上凿穿在Xiaohaizi形成揭示超过十米沙滩免职的高精力的biospararenite。这个特征与在中间、北的盆的相等的地平线的低精力的micritic石灰石相当不同。如此的典型碳酸盐沙滩和站台边缘背景显示为礁石生长导致的环境。根据3-D的解释600km2Xinbaza调查上的地震数据，面向在的25km长的堡礁一东方向西，方向与圆丘般的几何学被描出，12km宽南方剧降礁石前面，和36km宽北方剧降backreef。礁石撑墙和轮廓也在连贯，振幅，和频率属性的Xiaohaizi形成以及地平线片的一张isopach地图上被显示出。礁石在矩形的3-D的范围以外扩大地震调查。Xiaohaizi形成的厚度是在中央礁石，和比礁石的外面大的12m的超过60m。堡礁由由狭窄的潮汐的入口分开的片断组成。礁石的邻居主要是bioclasticgrainstones的沙滩免职。由于迟了的宰相和晚第三列的构造运动，堡礁被倾斜蘸在一个SWW方向。它的updip部分被一套反向的差错打破并且错放。不过，与礁石有关的大量烃储备的潜在的stratigraphic水池被期望在它旁边基于实质的礁石规模和最近的地上凿穿指示在未来被成立。

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.