位于陆壳与洋壳之上的大陆边缘记录了大陆裂解-大洋打开的全部过程,是研究地球动力学的重要场所.南海北部深水区盆地位于南海北部大陆边缘,新生代盆地表现为裂陷期盆地、裂后拗陷期盆地及裂后洋盆沉降期盆地3层结构.裂陷期盆地表现为一系列地堑及半地堑结构,拗陷盆地表现为中间厚两侧薄的“碟形”盆地特征,裂后拗陷期盆地表现为大陆坡局部加厚,向南海洋盆方向厚度逐渐减薄的“挠曲”盆地形态.南海北部深水区盆地经历了3期构造演化过程,盆地表现出不同的动力学机制.裂陷期盆地受地幔物质上涌影响表现为水平伸展作用为主,盆地内普遍发育伸展构造样式,裂后拗陷期盆地表现为区域均匀沉降特征.而裂后洋盆沉积期受南海强烈沉降作用的影响表现出明显的向南海洋盆倾斜特征.大陆架-陆坡-深海平原的构造格局主要形成于裂后洋盆沉降期.南海及其北部盆地下伏地幔物质活动的差异性决定了盆地内的3层结构的形成演化过程.%Continental margins, which locate in the continental crusts and oceanic crusts, record the processes of the continental breakup and the ocean opening. It is important for the research on the geodynamics. The Cenozoic basins in deep water of northern margin of South China Sea located on the continental margin. The Cenozoic basin can be divided into three structural layers. They are rift layer, post-rift depression layer and post-rift subsidence of ocean basin layer. Rift basin layer performed as a series of graben and half graben. The character of post-rift depression layer is thick in the middle and thin on both side which looks like a disk. The thickness of post-rift subsidence of ocean basin layer changed greatly, it thick on the continental slope and thin on the ocean basin which showed the character as a "flexing basin". The basin in deep water of northern margin South China Sea has experienced three evolution stages and showed the different geodynamic mechanisms. Influenced by the upwelling of the mantle, the basin mainly performed as horizontal extensional and formed the extensional structural styles in rift stage. In post rift stage, the basin subsided widely. In the third stage, the basin bended towards the South China Sea which controlled by the subsidence of ocean basin. The structural framework of continental shelf - continental slope - ocean basin is formed in the stage of ocean basin subsided. The activity difference of mantle material which under the basin of northern margin and the ocean basin is the main influence factors of the geodynamics.
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