【摘要】 为了解南海北部下陆坡深水盆地的沉积特征和地层分布对构造环境的影响,利用973、SO49等航次所获得的地震测线,对南海北部大陆边缘深水区下陆坡盆地新生代地层层序进行了划分,并与北部的白云凹陷的层序进行了对比,识别出了8套地震反射层组,自上而下地层时代分别为上新世-第四纪(N2-Q)、晚中新世(N13)、中中新世(N21)、早中新世(N11)、晚渐新世(E32)、晚始新世-早渐新世(E32-E31)、中始新世(E22)和古新世-早始新世(E1-E21).在此基础上,对荔湾和潮南坳陷南部深水区内主要层组的沉积特征和沉积充填作了初步分析,认为南海中北部下陆坡区的构造演化可以分为3个阶段,分别为古新世-早渐新世的断陷-断坳陆相湖盆沉积阶段、晚渐新世的裂陷-坳陷过渡阶段以及新近系以来的热力学沉降半深水-深水沉积阶段,沉积环境经历了河流-湖泊-浅海-深海的演化过程.更多还原

【Abstract】 The Cenozoic stratigraphic interpretation of lower continental slope in the northern South China Sea is studied and compared with Baiyun sag,to understand the sedimentary characteristics and stratigraphic distribution of deep water basin for environmental impact of construction,based on the seismic profiles acquired by SO49 and 973 cruises.The Cenozoic sediments of lower continental slope in southern Baiyun sag can be divided into eight stratas,namely,Pliocene-Quaternary,Late Miocene,Middle Miocene,Early Miocene,Late Oligocene,Late Eocene-Early Oligocene,Middle Eocene,Paleogene-Early Eocene.The tectonic evolution of lower continental slope depressions can be divided into following stages:rifting,rifting-depression transitional and depression stages,while their depositional environments change from river to shallow marine and abyssa1,which results in different topography in different stages.The topographic evolvement in the study area includes three stages,that is,Neocene to present,Late Oligocene,Early Oligocene and Paleogene.更多还原