简介：Theso-called“Yangtze-type”copperdepositsinclude:（1）Cu-bearingmassivepyritebed,(2)Cu-bearingskarnandmagnetite-typeoredeposits,withreplacementCu-vein-typedepositsnearthemetasomaticzone,and(3)mineralizedintrusivebodiesandbrecciapipes,someofwhichareknownasporphyrycopperores(e.g.Chengmenshan).ThistypeoforedepositsisatypicalexampletoverifythepolygenesisofinostofthedepositsinChina,ashasbeenpromotedbyProf.TuGuangchiinviewofthepolycyclicdevelopmentofthegeologicalhistoryinChina.Thispaperiscon-cemedwithonesub-typeofsuchdeposits.

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简介：Aglobal-scaleglaciationoccurredatabout600Maago.Asaresult,theEarthbecamethe'SnowballEarth'.Theglaciationcametotheendabruptlywhenatmosphericcarbondioxideincreasedtosuchanextentastobeabout350timesthemodernlevelbecauseofsubaerialvolcanicdegassing.TherapidterminationofglaciationwouldhaveledtowarmingoftheSnowballEarthandextremegreenhouseconditionswouldhavebeencreated.Thetransferofatmosphericcarbondioxidetooceanswouldgiverisetotherapidprecipitationofcalciumcarbonateinwarmsurfaceseawaters,thusformingthecapcarbonaterocksasobservedworldwidetoday.Regionallypersisting,thinlayersofcarbonaterocksdirectlyandubiquitouslyoverlieProterozoicglacialdepositsalmostoneverycontinent,andarecommonlyreferredtoascapcarbonates.Theirunusuallitho-fabrics,stratigraphicallyabruptbasalandupper-levelcontactsandstronglynegativecarbonateisotopicsignatures(δ13Ccarb.valuesrangefrom-7.0‰-0‰)suggestachemicaloceanographicorigin,thedetailsofwhichremainunknown.Itisproposedthattheseenigmaticdepositsarerelatedtothedestabilizationofgaseoushydrateinterrestrialpermafrostfollowingrapidpostglacialwarmingandfloodingofwidelyexposedcontinentalshelvesandinternalbasins.Theauthorscarriedoutstudiesonthegeochemistry,sedimentologyandpalaeontologyoftheSiniancapcarbonatesinGuizhouandHunanprovinces,includingtheoccurrenceofcapcarbonatesofunusualfabrics,stronglynegativecarbonisotopicsignatures,andalotofbitumennodules.Fromtheresultsitissuggestedthatthecapcarbonateswereformedfromsolidmethaneseepage,anditisinagreementwithKennedy'sviewpoint(2001)thatthecapcarbonatesresultedfromtherapidprecipitationofcalciumcarbonateinresponsetosolidmethaneseepage.

简介：TherearetwomaintypesofirondepositsintheMiddle-LowerYangtzeValleydistrict.Bothofthemunderwentpost-magmatichydrothermalprocessesduringoreformation.Ironinthehydrothermalorebodieswasderivedlargelythroughmobilizationfromsubstantiallyconsolidateddiroiticintrusives.Wall-rochalterationzonationindicatesthatiron-mobilizinghydrothermalfluidsevolvedinatrendofdecreasingalkalinity,whichissuggestedbyregularlydistributedwall-rockalterationsformedbyiron-mobilizinghydrothermalfluidsandisincontradictionwiththecurrentchloride,chloridecomplexandbicarbonatemodelsforironmobilization.ThecloseassociationofcarbonatizationwithironoresandthehighconcentrationsofreducedgasessuchasCO,CH4andH2influidinclusionssuggestthatironismostprobablytransportedintheformofironcarbonylsduringpost-magmatichydrothermalprocesses.Inthelightoftheironcarbonylmobilizationmodel,explanationsaremadeoftheconstraintsonoresofsomegeologicfactorssuchasmelanocraticalteration,carbonatization,carbonatestrata,structuralfractures,cyptoexplosivepipesandembryoores.

简介：溶解无机的滋养的元素从在2003年3月在Changjiang(长江)河口的南方经过收集的样品被分析，includingNH_4~+，NO_3~-，NO_2~--)并且PO_4~(3-)。水样品在三个车站在近表面、中间、近底部的深度时时与一个Niskin刺绣花样被收集—A1，A2和A3—在小潮和大潮的二个完全的潮汐的周期期间。结果显示出那1)当PO_4~(3-)显示出一个相反的趋势时，集中ofNH_4~+，NO_3~-和NO_2~-在大潮期间比那些在小潮期间分别地是高一些的，并且各比在涨潮在落潮是更高的，为小潮的任何一个潮汐的周期或春天潮汐的周期；2)营养素的更高的层化在这个区域显然存在与哪个从底部增加了到表面的集中，特别为NH_4~+和NO_3~-；3)所有溶解无机的营养素的变差系数(C.V)价值在潮流和Changjiang流量的不同影响以外从4.06%～36.8%变化了；4)与在水列增加浮游物，PO_4~(3-)的集中在过滤的水里变得更低；并且5)每个潮汐的周期的全部的运输是更，在大潮，比在小潮，和positive，价值显示营养素被出口了到华东海。研究在变化和在theChangjiang河口的南方经过的溶解无机的营养素的网运输将在华东海为红潮的机制的学习提供科学基础。

简介：TheUpperSinianbeddedchertsarewidelydistributedonthesoutheastcontinentalmarginoftheYangtzeplate,withatotalthicknessrangingfrom20to150m,Thechertsareverysimpleinchemicalcomposition,withthecontentsofsiliceousmineralsexceeding90%andthoseofothermineralspeciesbeingverylow.Thetotalcontentoftraceelementsisconsiderablyvarialbe,Thecontentsofmosttraceelementsarelowascomparedwiththeircrustclarkevalues.ButthesechertsareveryrichinthetraceelementsBa,As,Ab,AgandU,coupledwithrelativelyhighcontentsofFe,MnandlowcontentsofAl,Ti,andMg,ItcanbeidentifiedasthechertsofhydrothermaloriginintermsofthevaluesofFe/Ti,(Fe+Mn)/Ti,Al/(Al+Fe+Mn)andU/Th,IntheAl-Fe-Mn,andFe-Mn-(Cu+Ni+Co)×10diagramsandlg[U]-lg[Th],Cr-Zrdiagrams.allthesamplesfromtheareastudiedfallwithinthehydrothermalsedimentfield.Allthesecharacteristicsshowthatthechertsaremainlytheproductofhydrothermalprocesses.Thefactthattheδ30Sivaluesofthechertrangefrom0.0‰to0.7‰withδ18Ofrom20.1‰to23.6‰cleralymanifeststhatthesubmarinehydrothermalwateristhemainsourceofsilica.

简介：我们进行了孵化试验在中国在Changjiang河河口和它的邻近的水在不同磷酸盐集中和发光下面在浮游植物的滋养的举起调查变化的舷侧。在100%天赋发光下面，磷酸盐，硅酸盐，和硝酸盐的举起率在高磷酸盐层次(1.84亩M)被加速，当在低发光(大约50%自然发光)下面他们的举起率在高度被制止，但是在中间的磷酸盐集中极大地刺激了时(1.26嗯)作为浮游植物的生长，在亚硝酸根和铵举起的变化没跟随一个明显的模式。我们的结果也证明在在低、高的发光下面的不同磷酸盐集中在硝酸盐，硅酸盐和磷酸盐举起之间有线性关系，并且浮游植物的生长时期在低发光下面在高发光下面并且在中间的集中在高磷酸盐集中两个都被延长，建议浮游植物生长的限制主要在它的生长时期反映了变化，并且因为如此的环境(低发光和低磷酸盐集中)都实际上没在一个高混浊地区存在，浮游植物花蕾几乎没发生在那里。当发光不在时，脱氮乐意地发生了，浮游植物被作为减少，它导致了磷酸盐新生。