简介：DifferentmodelshavebeenproposedfortheformationandtectonicevolutionoftheSouthChinaSea(SCS),includingextrusionoftheIndochinaPeninsula,backarcextension,two-stageopening,proto-SCSdragging,extensioninducedbyamantleplume,andintegratedmodelsthatcombinediversefactors.Amongthese,theextrusionmodelhasgainedthemostattention.Basedonsimpli?edphysicalexperiments,thismodelproposesthatcollisionbetweentheIndianandEurasianPlatesresultedinextrusionoftheIndochinaPeninsula,whichinturnledtoopeningoftheSCS.TheextrusionoftheIndochinaPeninsula,however,shouldhaveledtopreferentialopeninginthewestsideoftheSCS,whichiscontrarytoobservations.ExtensionalmodelsproposethattheSCSwasabackarcbasin,riftedofftheSouthChinaBlock.Mostofthebackarcextensionmodels,however,arenotcompatiblewithobservationsintermsofeitherageorsubductiondirection.Thetwo-stageextensionmodelisbasedonextensionalbasinssurroundingtheSCS.Recentdatingresultsindeedshowtwo-stageopeningintheSCS,buttheSouthwestSubbasinoftheSCSismuchyounger,whichcontradictsthetwo-stageextensionmodel.Hereweproposeare?nedbackarcextensionmodel.TherewasawideNeotethysOceanbetweentheAustralianandEurasianPlatesbeforetheIndian-Eurasiancollision.Theocean?oorstartedtosubductnorthwardat*125Ma,causingbackarcextensionalongthesouthernmarginoftheEurasianPlateandtheformationoftheproto-SCS.TheNeotethyssubductionregimechangedduetoridgesubductionintheLateCretaceous,resultinginfold-belts,uplifting,erosion,andwidespreadunconformities.Itmayalsohaveledtothesubductionoftheproto-SCS.FlatsubductionoftheridgemayhavereachedfurthernorthandresultedinanotherbackarcextensionthatformedtheSCS.Therollbackofthe?atsubductingslabmighthaveoccurred*90Maago;thesecondbackarcextensionmayhaveinitiatedbetween50and45Ma.TheopeningoftheSouthwestSub

简介：TheCandHisotopiccompositionsofthemethaneinmorethan160gassamplesfrom10basinsinChinaarepresentedinthispaper.Thenaturalgasesareclassifiedasfourtypes:biogenicgas,bio-thermocatalytictransitionalgas,gasassociatedwithcondensateoil,andcoal-typegas.Theisotopiccompositionsofthesegasescloselyrelatedtothedepositionalbasins,thetypesoforganicmatter,thestagesofthermalevolutionandthegeneticcharacteristicsofdifferentgasreservoirs.StudiesoftheCandHisotopiccompositionsofterrigenousnaturalgaseswillprovidevalua-bleinformationontheprospectinganddevelopmentofnaturalgasesofdifferentgenetictypes.

简介：ThickenedheavyoilsinChinaaregeneticallycharacteristicofcontinenta.Astotheirphysico-chemicalproperties,theseoilsareveryhighinviscosityandlowinsulphurandtraceelementcon-tents.Inthegroupconstituents,theconcentrationsofnon-hydrocarbonsandasphalteneareveryhighbutthoseofsaturatedhydrocarbonsandaromaticsareverylow.Thegaschromatogramsofalkanesshowthattheseheavyoilshavehighabundancesofiso-alkanesandcyclichydrocarbons.Inallthesteroidsandterpenoids,bicyclicsesquiterpenoids,tricyclicditerpenoids,re-arrangedsteranesandgammaceranearestronglybildegradation-resistent.Theformationofheavyoilreservoirsiscontrolledmainlybylatebasinascendance,biodegradation,flushingbymeteoricwaterandoxidationintheoil-bearingformations.Ac-cordingtotheirformationmechanisms,heavyoilreservoirscanbeclassifiedasfourcategories:weatheringanddenudation,marginaloxidation,secondarymigrationandthickeningofbottomwater.Spacially,heavythickoilreservoirsaredistributedregularly:theyusuallyshowsomeparageneticrelationshipswithnormaloilreservoirs.Heavyoilreservoirsoftenoccurinstructuralhighsorinoverlyingyoungerstrata.Theirburialdepthisabout200m.Horizontally,mostofthemaredistributedonthemarginsofbasinsordepressions.

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简介：Theauthorshaveproposedadynamicmodelinthispaperbasedontheages,rockseriesandassociations,Sr-NdisotopicsignaturesoftheMesozoicintracontinentalmagmatismoverlyingtheCathaysianandYangtzeblocks.ThemodeldescribestherelationofintracontinentalcollisionandsubductionintheTethyantectonicregiewithPaleo-Pacificoceanicplatesudbuction-strikeslip-extensioninthePacifictectonicregime.During220-150Ma,thehorizontalcollisionbetweentheNorthChinablockandtheYangtzeblock,aswellastheintracontinentalsubductionofsomedivergentmicrocontinentalterranesinthesouthwesternpartofSouthChinaareascribedtotheinfluenceoftheTethyantectonicregime,givingrisetoavolumeofhigh-Israndlow-εNd(t)S-typegranitesonlyintheCathaysianBlock.During145-90Ma,underthegeodynamicbackgoundofsubduction-strikeslip-extensionofthePaleo-PacificoceanicplateonthebasisofthedeeptectonicprocessintheTethyantectonicregime,high-K,alkalirichcalc-alkalineandshoshoniticvolcano-plutoniccomplexesweregeneratedintheYangtzeblock,andhigh-Kcalc-alkalicandbimodalvolcano-plutoniccomplexesweregeneratedintheCathaysianblock.TheoccurrenceofA-typeperalkalinegranitesinthecoastalareasofSoutheastChinaindicatestheendofMesozoicintracontinentalmagmatism.

简介：GranitoidsarewidelyspreadintheNanlingRegionofChina.FourrockbodiesintheregionthebeenstudiedfortheirREE,Rb,Sr,BaandScdistributions.Thefourrockbodiesoccurredindifferentlocationsandarecharacterizedasbeingdifferentinageandtype.Therocktypesarepresentedasfollows:Qinghumonzonite,Guangxi;Fuxigranodiorite,Guangdong;Jiufengmonzoniticgranite,Hunan;ZudongK-feldspargranite,Jiangxi.FromthemajorandtraceelementdistributionsinthesegranitoidsitisclearlyshownthatRb/SrratiosintherockstendtoincreasewithincreasingSiO2contentanddifferentiationindex(DI),butLREE/HREE,La/YbandK/Rbratiostendtodecrease,suggestingacorrelationbetweentraceelementdistributionandmajorelementcompositionforthegranitoids.Thedistributioncharacteristicsoftraceelementsineachoftherockbodiesaredescribedindetail.FromthecomparativeanalysisoftheQinghumonzoniteandFuxigranodioriteitisevidencedthattheREEdistributioniscloselyrelatedtothesequenceofcrystallizationfortheminerals,andalsotothepetrochemicaltypesofthesegranitoidsinadditiontotheircrystalchemistry.

简介：在在西南贵州的Lanmuchang的一个农村区域的水系统正在面对铊(Tl)的风险污染由于在区域附近的Tl矿化作用。在水系统的主要痕量元素和Tl被学习由Tl矿化作用理解Tlconstrained的hydrogeochemical过程。结果证明Tl的分散模式从矿地下水(深地下水)在集中跟随果汁饮料scending顺序→溪流水→s使神圣地下水→背景水，在thehydrogeochemical作文上反映Tl矿化作用的影响。在两政体的溪流水里的Tl集中显著地更高(2-30褶层)比up-streams,和中流下游，可能由深地下水的未辩别出的分泌物引起了。然而，低Tl层次在当前的饮料水被检测溪流水和潜水里的高度提高的Tl可以通过每日的洗和农业灌溉提出潜在的环境风险。这研究建议人的活动例如农业灌溉，能加强Tl的环境风险。

简介：REEgeochemicalstudiesofsurficialsedimentsamplesfromtheYellowSeaofChinahaveshown:(1)TheaveragecontentofRE2O3intheYellowSeasedimentsis175ppm,closetothatintheEastChinaSeasediments.TheREEdistributionpatternsintheYellowSeasedimentsarealsosimilartoanomalies.TheseREEcharacteristicsaretypicalofthecontinentalcrust.(2)ThecontentsofREEarecontrolledmainlybythesedimentgrainsize,i.e.,REEcontentsincreasegraduallywithdecreasingsedimentgrainsize.REEarepresentmainlyinclayminerals.Inaddition,REEcontentsarecontrolledobviouslybyheavyminerals.REEabundancesinheavymineralsaremuchgreaterthanthoseinlightminerals.(3)CorrelationanalysisshowsthatREEhaveacloserelationshipwithsiderophileelements,especiallyTi,whichhasthelargestcorrelationcoefficientrelativetoREE.TerrigenousclasticmaterialssubjectedtoweatheringandtransportaresuggestedtobethemainsourceofREEintheYellowSeasediments.

简介：Sediment-hostedgolddepositsarethemajortypeofgoldresourcesinchina,Concentratedmostlyinthetwo'TriangleRegios',theyaregenerallyhostedinfine-clasticturbidite,hydrothermalchetandmarlrangingfromcambriantoTriassicinage,structurallycontrolledbydomes,anticlinesandsecond-orderedfaults.TheyaresimilartotheCarlin-typegolddepositsinmineralassemblageandgeochemicalmarks,withanelementassociationcloselycomparabletothoseofmodernspringsandsubmarinehydrothermalsediments.Organicmattermayhaveplayedanimportantroleinmineralization.Theoresolutionmaybehydrothermallyalteredmeteoricwaterdevelopediareasoflocalgeothermalanomaly.

简介：VolcanicrocksinseamountsoftheSouthChinaSeaconsistmainlyofalkalibasalt,tholeiiticbasalt,trachyandesiticpumice,dacite,etc.Inclusionsinthemineralsofthevolcanicrocksaremain-lyamorphorsmeltinclusions,whichreflectsthatthevolcanicrocksarecharacterizedbysubmarineeruptionandrapidcoolingontheseafloor.Furthermore,fluid-meltinclusionshavebeendiscoveredforthefirsttimeinalkalibasaltsandmantle-derivedxenoliths,indicatingaprocessofdifferentiationbetweenmagmaandfluidinthecourseofmantlepartialmelting.Alkalibasaltsandinclusionsmayhavebeenformedinthisnonhomogeneoussystem.Rock-formingtemperaturesoffourseamounsestimatedasfollows:theZhongnanseamountalkalibasalt1155-1185℃;theXianbeiseamountalkalibasalt960-1200℃;tholeiiticbasalt1040-1230℃;theDaimaoseamounttholeiiticbasalt1245-1280℃;andtheJianfengseamounttrachandesticprmice880-1140℃.EquilibriumpressuresofalkalibasaltsintheZhongnanandXianbeiseamountsare13.57and8.8×10^8Pa,respectively.Pyroxeneequilibriumtem-peraturesofmantlexenolithsfromtheXianbeiseamountwereestimatedat1073-1121℃,andpres-suresar(15.58-22.47)×10^8Pa,suggestingadeep-source(e.g.theasthenosphere)forthealkalibasalts.

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简介：ThecharacteristicstructuresofthePrecambrianchertsfromtheGusuisection,Guangdong,Chi-na,includebeddedstructure,laminatedstructure,massivestructureandpseudobrecciatedstructure.ThechertischaracterizedbyconsistentlylowabundanceofTiO2,Al2O3andmosttraceelements.Howevver,itisenrichedinBa,As,Sb,HgandSe.InAl-Fe-Mnternarydiagrams,itfallsintothe'hydrothermalfield'.Correspondenceanalysisandfactoranalysisshowthatmanyelementsshowupinthefactorthatrepresentstheleachingofcountryrocksbyhydrothermalsolutions,andaretheverycharacteristicelementassociationfothegeochemicallyanomalousSouthChinabasement.Petrologicandgeochemicalevidencesuggestsahydrothermaloriginforthechert.ThechertmayhavebeenformedinaPrecambrianfiftoranextensionzonedevelopedwithintheYunkaimarginalgeosyncline,withafaultsystemlinkingittoanunknownheatsourceatdepth.

简介：Variationsinthedistributionsofcarbazolesanddibenzothiopheneswereinvestigatedinasetofsourcerocks,whichdiffermainlyintheirmaturitylevelsduringimmature-maturestages.Acomparisonofthedistributionsofcarbazolesanddibenzothiopheneshasrevealedthemainresultsasfollows:variationsintherelativeamounts①ofC0-,C1-,C2-dibenzothiophenesshowalowcorrelationwiththatofthecorrespondingcarbazoles,withtheformer'sbeingmuchhigherthanthelatter's;variationsintherelativeamountsofmethyldibe②nzothiopheneisomersalsodisplayalowcorrelationwiththatofthecorrespondingmethylcarbazoles,with4-/4-+1-methyldibenzothiopheneratiorangingfrom0.52to0.96,whilethecorrespondingcarbazoleratioof1-/1-+4-methylcarbazoleonlybeing0.71±0.05;themat③urityparameterfor4,6-/4,6-+1,4-dimethyldibenzothiohene,rangingfrom0.34to0.75,showsaremarkablelinearcorrelationwiththecorrespondingratioof1,8-/1,8-+1,4-dimethylcarbazole(R2>0.84).Theun-correlationmayindicatesomedifferentgeological-geochemicalfatesforsomeisomersofdibenzothiophenesandcarbazoles.Thehighcorrelationmayrevealastrongmaturationdependenceonthedimethylcarbazoledistributions,indicatingthatattentionshouldbepaidwhen1,8-/1,8-+1,4-dimethylcarbazoleisusedasapetroleummigrationindicator.

简介：TheHuhehuSagisoneofthemostimportantoilandgasdepressionsintheHailarBasin.However,theoriginofHuhehuoilisstillcontroversial.PreviousstudiesonsourcerockshavemainlyfocusedontheNantunFormation(K1n);afewstudieshaveinvestigatedtheDamoguaiheFormation(K1d).BasedontheRock–Evalpyrolysisparameters,172drillcuttingsamplesfromtheHuhehuSagwereanalyzedtoevaluatetheirgeochemicalcharacteristics.BasedontheRock–Evaldata,themudstonesfromthefirstmemberoftheDamoguaiheFormation(K1d1)andthesecondmemberoftheNantunFormation(K1n2)havemoderatetohighhydrocarbongenerationpotential,whilemudstonesfromthefirstmemberoftheNantunFormation(K1n1)havepoortogoodhydrocarbongenerationpotential.Additionally,boththeK1n1andK1n2coalmembershavepoortofairhydrocarbongenerationpotential,buttheK1n2coalmemberhasabettergenerativepotential.FifteenHuhehuoilswerecollectedformoleculargeochemicalanalysestoclassifytheoilsintogeneticfamiliesandtoidentifythesourcerockforeachoilusingchemometricmethods.TheHuhehuoilswereclassifiedintothreegroupswithdifferentmaturitylevelsusinghierarchicalclusteranalysisandprincipalcomponentanalysis.GroupAoils(highmaturity)arecharacterizedbyrelativelymoderateratiosofPr/Ph,Pr/n-C17,andPh/n-C18,aswellasanabundanceofC29steranes,mainlyderivedfromtheK1n2andK1n1mudstonemembers.Incomparison,groupBoils(moderatematurity)haverelativelylowPr/Phratios,moderatePr/n-C17andPh/n-C18ratios,andlowconcentrationsofC29steranes.GroupCoils(lowmaturity)showrelativelyhighratiosofPr/Ph,Pr/n-C17,andPh/n-C18,aswellashighconcentrationsofC29steranes.Furthermore,groupBoilsderivedfromtheK1d1mudstonememberandgroupCoilsderivedfromtheK1n2coalmemberwerealsoidentifiedbyprincipalcomponentanalysisscoreplots.CorrelationstudiessuggestamajorcontributionfromtheK1nmudstoneFormation

简介：TheoccurrenceandgeologicalgenesisofpyritesinLatePaleozoiccolasofNorthchinahavebeensystematicallystudiedintermsofcoalpetrology,coalchemistry,elementalgeochemistryandsulfurisotopegeochemistry.Theresultssuggestthateighttypesofpyrite,i.e.,framboidal,automorphicgraular,oolitic,massive,homogeneousspherical,allotriomorphic,nodular,joint-andfisure-fillingpyrintescanbesubdividedunderthemicroscope,Fourgenerationsofpyritearealsoreconizedaccordingtotheshape,size,coexistingassemblage,spacialdistributionrelationshipwithmacerals,thecontentsofsulfurandiron.atomicS/Feratiosandassociatedelementsinpryites.SulfurinLatePalozoiccolasofNorthChinaisofdiversesourceasevidencedbysulfurisotopevariationsinthepyrites.Theδ34Svaluesofpyritegeneratedattheearlystagetedtobenegative,andatthelatestage,positive.

简介：TheMaomingBasinisoneamongstagroupofCretaceous-TertiarybasinsinSouthChina.347sampleswerecollectedfromdrillcoresMRandMBandsectionMS(110°54ˊE,21°45ˊN).MostofthelithologicalunitsareofTertiaryage.ThecoresincludetheLaohuling,Shangun,HuangniulingandYouganwoformations.TheMRcore(874minlength)hasrecordedthepolarityhistoryfromNormalZone18toNormalZone11ontheGeomagneticPolarityTimeScale(GPTS).Thestratawereformedfromabout42Mato32Ma,thatisfromLateEocenetoEarlyOligocene.Ameansedimentationrateofthisstratigraphiccolumnis8.1cm/ka.