简介:关于矿物质的70-80子类型包括的一组披风矿物质在西藏从podiformchromitite被发现,中国。恢复矿物质包括钻石,coesite,moissanite,wustite,Fe-silides和一种新矿物质,luobusaite。这些矿物质的AM是hand-pickedfrom重矿物质在luobusaite的谷物作为有本国的硅或作为有本国的硅和Fe-Si阶段的共生交互生长的包括的主人矿物质的ophiolite.The的披风橄榄岩podiformchromitite分开。Luobusaite作为不规则的谷物发生,与在尺寸的0.1-0.2公里,由很有细密纹理的总数组成。矿物质是在颜色的钢灰色,金属性的光泽,并且不透明。实验公式(基于2为Si)是Fe_(0.83)Si_2,根据luobusaite的化学成分。X光检查粉末衍射数据:斜方晶的系统,空格组Cmca,a=9.874(14)一,b=7.784(5)一,c=7.829(7)一,Z=16。
简介:CentralAsiaencompassesnearlyadozencountriesandconsistsofseveralorogeniccomplexes,oneofwhich,theAltaids,isca.1000kmwideand7000kmlong,stretchingfromtheUralMountainsintheWesttothePacificOceanintheEast.ItiscomposedofseveraltectoniccollagesthatwerecreatedbyoceanicsubductionandcontinentalcollisionfromtheLateProterozoictotheendofthePalaeozoic.Thelastdecadewitnessedtheestablishmentoftwocompetingtectonichypothesesforthedevelopmentoftheseorogeniccomplexes.Thefirstviews
简介:ProjectNo.506MarineandNonmarineJurassic,ProjectNo.508Volcano,CollapseandFaultActivity--“YoungScientistsProject”,ProjectNo.509PalaeoproterozoicSupercontinentsandGlobalEvolution,ProjectNo.510A-typeGranitesandRelatedRockthroughTime,ProjectNo.511SubmarineMassMovementsandtheirConsequences.
简介:Theinterdisciplinaryfieldrespondstotheneedtobetterof"MedicalGeology"understandtherelationshipsbetweenhumanhealthandoursurroundingenvironment.Theinfluenceofearthresources,naturalenvironmentalfactorsandland-useonhumanhealthhaslongbeenrecognized,datingbacktoancientRomeandPeru'sIncacivilization.Todaylinksbetweenthenaturalenvironmentandhealthcanbefoundthroughouttheworld.Thisreviewintroducesthehistoricalcontextofthisparticulartypeofresearch,contraststhedirectgeologicalandindirectnaturalhazardinfluencesonhealthasaframeworkofstudy,elaboratesonpathwaysofelementalaccumulationinthebodyandprovidesexamplesofspecificgeochemicalbehavioursanddiseasesthatareoftenassociatedwitheithertoomuchornotenoughofcertainelementswhichcomprisetheEarth.
简介:PelagicmanganesenodulesfromtheEastPacificOceanhavebeenstudiedusingpolarizing,scanningelectronandtransmissionelectronmicroscopes.Ithasbeenrevealedthatthemanganesenodulesarecomposedofcoresandstromatolitecoatings.Thestructuresandtexturesofthesenodulesarepeculiartooncolite.Consequently,thepelagicmanganesenodulesaremanganeseoncolites.Basedonthestromatolitesinthecoatings,themanganeseoncolitesfromtheEastPaci-ficOceancanbedividedintotwotypes.Oneissmoothonsurfaceanddenseinside.ItscoatingsarecomposedmainlyofMinima.Theotherhasaknobbysurfaceandislooseinternally.ItscoatingsconsistmainlyofAdmirabilis.TheTEMinvestigationhasalsorevealedthatthecon-structorsofthemanganeseoncolitesareultra-microbes.TheMinimaisconstructedbyMiniactinomyceschinensissp.nov.andtheAdmirabilisisbuiltbySpirisosphaerosporapacificasp.nov.
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简介:X-raydiffraction(XRD)peaksinalow-anglediffractionsectionofclayminerals,especiallythoseofauthigenicorigin,havebroadeningandtailingfeaturesinshape.Usingthefivebasicparameters,peakposition,peakheight,width,shapecoefficientandasymmetry,todescribeanXRDpeakismoreaccurate,comprehensiveandintegratedthanusingonly3ofthem,position,heightandwidth.FollowingtheconceptofthefivebasicparametersofanXRDpeak,theprogramDecoformproposedinthisstudyprovidesmoreinformationinmineralogicalanalysesbyfittingactualXRDprofiles.IncombinationwiththeHW-IRplot,Decoformcanbesystematicallyandaccuratelyusedinthecomprehensiveanalysesofcrystallinity,domainsize,latticestrainandquantitativephase.Itisalsoofvalueforthegeologicalinvestigationsofdiagenesis,metamorphism,basinmaturity,structuralstressfieldandsoon.
简介:Inthegeoscientificcommunityoftheworld,avarietyofproposalsareknownashypothesestoex-plainthedynamicsofthecarth.Theseincludeplatcteetonics,theundationhyPothesis(vanBemmelen,1933),themodernexpanding-earthhypothesis(Carey,S.W.,1976),theupheavalocean-floorhypothesis(Hoshino,M.,1975),theoceanizationhypothe
简介:AGeologicTimeScale(GTS2004)ispresentedthatintegratescurrentlyavailablestratigraphicandgeochronologicinformation.Keyfeaturesofthenewscaleareoutlined,howitwasconstructed,andhowitcanbefurtherimproved.TheaccompanyingInternationalStratigraphicChart,issuedunderauspicesoftheInternationalCommissiononStratigraphy(ICS),showsthecurrentchronostratigraphicscaleandageswithestimatesofuncertaintyforallstageboundaries.SpecialreferenceismadetothePrecambrianpartofthetimescale,whichiscomingofageintermsofdetail,andtotheNeogeneportion,whichhasattainedanultra-high-precisionabsolute-agecalibration.
简介:AttheInternationalGeologicalCongressheldinFlorence,ItalyinAugust2004theIUGSCouncilapprovedtheformationofanewCommissiononGeoscienceforEnvironmentalManagement.ThisnewCommissionwasformedtocontinueIUGSactivitiesintheenvironmentfollowingtheclosureoftheIUGSCommissiononGeologicalSciencesforEnvironmentalPlanning(COGEOENVIRONMENT)whichhadcompleteditsterm(refertoseparatearticleinthisissue).