南大西洋被动陆缘沉积物厚度特征与分段对比

基于美国国家海洋和大气管理局(NOAA)发布的最新全球沉积物厚度数据, 综合利用被动陆缘盆地、洋底高原和转换断层等地质信息, 识别南大西洋七大沉积中心。南大西洋沉积物厚度整体上呈西厚东薄、北厚南薄的趋势, 按陆缘及盆地特征, 将大西洋两岸盆地从北到南划分为4段: 赤道段、中段、南段和福克兰段,其中被动陆缘盆地主要分布在前3段。赤道段盆地主要受转换断层控制, 发育三叠系蒸发岩; 中段盆地发育阿普第阶盐沉积, 是油气勘探的重点区域; 南段受火山活动的影响, 以发育向海倾斜反射体为主要特征。

Sedimentary Characteristics and Tectonic Segmentation of the PassiveContinental Margin of the South Atlantic Ocean

Seven major sediment centers were recognized based on the Total Sediment Thickness of the World’sOceans and Marginal Seas (NCEI, NOAA), integrated with the research on the passive margin basins, oceanicplateaus, main transform faults. It could be revealed that the western and the northern parts of the South AtlanticOcean have much thicker sedimentary than the eastern and the southern parts. The nature of sedimentary andtectonic of the passive continental margin and passive continental margin basins were discussed in four segmentsof South Atlantic Ocean Margin: equatorial segment, central segment, southern segment and Falkland segment. TheEquatorial segment was controlled by large transform faults, where the Triassic salt layer developed. The Aptiansalt layer was found in the Central segment, which was the key area of oil and gas exploration. Volcanism deeplyinfluenced the Southern segment with the Seaward Dipping Reflectors.