简介:ThereoccurabundantchertsintheMesozoicandCenozoicstratainsouthernTibet.Someofthempossesscharacteristichydrothermalstructuressuchaslayered,laminated,massiveandbrecciastructures.RatiosofAl/(Al+Fe+Mn),Co/Ni,Fe/TiandTiO2-Al2O3demonstratethattheiroriginisrelatedtohydrothermalsedimentation.ThechertformationshavecloserelationshipwithSb,Auandpoly-metallicmineralization,andtheore-formingfluidshowstrongcorrelationwithfossilhydrothermalwater.
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简介:ObjectiveTheYubeiareaislocatedinthemid-eastMaigaitislopeofsouthwesternTarimBasin,China,withanexplorationhistoryofseveralyears.RecentexplorationhaspreliminarilyindicatedthattheOrdoviciancarbonateformationsinthisareahavesomeoilandgaspotential.Carbonatemicrofaciesprovidesmaterialbasisforreservoirdevelopment,sealformationandhydrocarbon
简介:Sedimentaryfaciesisanimportantfactorinfluencingshalegasaccumulation.Itnotonlycontrollshydrocarbongeneration,butalsoaffectsreservoircharacteristicsanddistribution.ThispaperdiscussestheLowerSilurianLongmaxiFormationinthesouthoftheSichuanBasin.Outcrop,core,drillingandloggingdataidentifythesedimentaryfaciesoftheformationascontinentalshelffacies,whichisdividedintotwosubfacies:aninnershelfandanoutershelfsubfacies.Thesetwosubfaciescanbefurtherdividedintosevenmicrofacies:muddysiltyshallowshelf,calcareoussiltyshallowshelf,muddylimyshallowshelf,stormflow,muddydeepshelf,siltymuddydeepshelfandcontourcurrentmicrofacies.Verticalandhorizontaldistributionofmicrofaciesestablishesasedimentationmodelofthecontinentalshelffacies.Combinedwithanalizationorcalculationofgeochemical,mineralogical,physicalandgas-bearingpropertiesofsamples,sedimentarymicrofaciesisevaluatedusingnineparameters:totalorganiccarboncontent,effectiveshalecontinuousthickness,vitrinitereflectance,kerogentype,mineralcomponents,porosity,permeability,watersaturationandgascontent.Theevaluationrevealedthatthemostfavorablefaciesforshalegasexplorationanddevelopmentarethemuddydeepshelfandpartofthesiltymuddydeepshelfmicrofacies,withTOCmorethan2%,siliceouscomponentover50%,claylessthan30%,porositymorethan3%,watersaturationlowerthan40%,gascontentgreaterthan2m3/t.Theseresultsprovideatheoreticalbasisfordeciston-makingonthemostpromisingareasforshalegasexplorationintheSichuanBasinandformarineshalegasexplorationanddevelopmentinSouthChina.
简介:Theconeeptof"PolygencticandCompoundDcposit"wasproposedbyProfessorChenGuoda(1975,1977,1979,1982,1988).Thispapcrmakesuseofthethcorytothcrcscarchoncoalbedmethanedeposit,andproposestheidea"PolygeneticandCompoundCoa1bcdMethancDoposit"’Coa1bedmethanejsbotbgas-sclfgeneratingandgas-selfbcaringnaturalgas,sot