简介：Withprocessingandinterpretationof25000kmfull-coveragemultibeamswathdatafromtheeasternSouthChinaSea,itisfoundthatNE-trendingandNW-trendinglinearmorphologicalfeaturessuchasscarps,horstsandgrabens,govemthecentralpart(14°～17°N)ofeasternsubbasin.Comparedwithreflectionseismicprofiles,theseNE-trendinglinearmorpho-structuresareconsideredtobetherepresentationofbasementstructuresonseabedandcanbedividedintothreelinearstructuralzones.ThetrendofthecentralzoneisNE45°～50°occurringaroundextinctspreadingcenter,thetrendofthesecondzoneisNE70°～78°onbothsidesofthecentraloneandthetrendofthethirdzoneisaboutNE60°justonthenorthofthesecondone.ThesethreeNE-trendinglinearzonesareformedinlate-stageNW-SE-trendingseafloorspreadingoftheeasternsubbasinalongNW-trendinglinearfaults,andrespectivelycorrespondtothreespreadingepisodes:17.0～19.0Ma(5d-5e),19.0～21.0Ma(5e-6a)and21.0～24.2Ma(6a-6c)basedonthecontrastofmorpho-structurestomagneticlineationanomalies.

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