Sedimentary Characteristics of Relict Deposits on the Western South Yellow Sea

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摘要 Integratedstudiesofverticalsedimentarysequences,grainsizes,andbenthicforaminiferaandostracoda,incombinationwithAMS14Cdating,and210Pband137CsanalysiswerecarriedoutinthreevibracorestakenfromtheareaofrelictdepositsonthewesternSouthYellowSea.Therelictsands,whichareabout0.4mthick,overlieontheEarlyHolocenecoastalmarshortidalflatdepositswithanevidenterosionalinterfaceinbetween.Themiddleandupperpartsorsometimesthewholeoftherelictsandshavebeenreworkedunderthemoderndynamicenvironment.Thesedimentationratevariesbetween0.20–0.30cmyear-1.Therelictsandsshowabimodalgrain-sizedistributionpatterninfrequencycurves,withasharppeakinthecoarsefractionbetween3Φand4Φandasecondarypeakinthefinefractionofabout7Φ.Ofthebenthicforaminiferalandostracodassemblages,thereworkedrelictsandsarecharacterizedbythemixingofthenearshoreeuryhalineshallow-waterspeciesanddeeperwaterspecies.TheerosionalinterfaceatthebottomoftherelictsandsisconsideredasaregionalravinementsurfaceformedduringthetransgressionintheEarlyHoloceneduetoshorefaceretreatinglandwards.Therelictsandswereaccumulatedontheravinementsurfaceduringthetransgressioninthedeglaciationperiodaslagdepositsafterwinnowingandreworkingbymarinedynamicprocesses.Andthesecondarypeakoffinefractioninthefrequencycurvefortherelictsandssuggeststheinputoffine-grainedsedimentsduringthereworkingprocess.Astheconclusion,therelictsandsinthestudyareaareinterpretedasatypeofreworkedrelictsediments.
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出版日期 2014年02月12日(中国期刊网平台首次上网日期,不代表论文的发表时间)
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