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1、Sedimentology(2012)59,16771694doi:10.1111/j.1365-3091.2012.01321.xSea-levelrise,depth-dependentcarbonatesedimentationandtheparadoxofdrownedplatforms,,WONSUCKKIM*,BRUCEW.FOUKEà,ANDREWL.PETTER*,TERRENCEM.QUINN*,CHARLESKERANS*andFREDTAYLOR*DepartmentofGeologicalSciences,Universityo
2、fTexas,1UniversityStation,C9000,Austin,TX78712,USA(E-mail:delta@jsg.utexas.edu)InstituteforGeophysics,UniversityofTexas,10100BurnetRoad,R2200,Austin,TX78758,USAàDepartmentofGeology,UniversityofIllinois,1301W.GreenStreet,Urbana,IL61801,USAAssociateEditorJohnReijmerABSTRACTAmathemat
3、icalmodelofcarbonateplatformevolutionispresentedinwhichdepth-dependentcarbonategrowthratesdetermineplatform-topaccumulationpatternsinresponsetorisingrelativesea-level.Thismodelpredictsthatcarbonateplatformevolutioniscontrolledprimarilybythewaterdepthandsedimentaccumulationratecondi
4、tionsattheonsetofrelativesea-levelrise.Thelong-standingparadoxofadrownedplatformarosefromtheobservationthatmaximumgrowthratepotentialsofhealthyplatformsarefasterthanthoseofrelativesea-levelrise.Themodelpresentedheredemonstratesthatacarbonateplatformcouldbedrownedduringaconstantrela
5、tivesea-levelrisewhoserateremainslessthanthemaximumcarbonateproductionpotential.Thisscenariodoesnotrequireenvironmentalchanges,suchasincreasesinnutrientsupplyorsiliciclasticsedimentation,tohavetakenplace.Arateofrelativesea-levelrisethatishigherthanthecarbonateaccumulationrateatthei
6、nitialwaterdepthistheonlynecessaryconditiontocausecontinuousnegativefeedbackstothesedimentaccumulationrates.Undertheseconditions,thetopofthecarbonateplatformgraduallydeepensuntilitisbelowtheactivephoticzoneanddrownsdespitethestrongmaximumgrowthpotentialofthecarbonateproductionfacto
7、ry.Thisresulteffectivelyresolvestheparadoxofadrownedcarbonateplatform.Testmodellingrunsconductedwith2Æ5mand15minitialseawaterdepthsatbracketedratesofrelativesea-levelrisehavedeterminedhowfastthesystemcatchesupandmaintainsthekeep-upphase.Thisisthemeasureoftimenecessaryforthebasintor
8、espondfullytoexternalforci