Based upon new seismic reflection data, this study reveals the development of a complex sedimentary system on the lower-slope terrace off Maputo on the southern Mozambique margin. The deep-water sedimentary system clearly shows the interaction of downslope and alongslope processes. Downslope features include: a pronounced canyon, slope creep, submarine slides, and multi-stage mass-transport deposits. Alongslope features include: contourite drifts and sediment waves, erosional moats, valleys, erosive surfaces and a distinctive contourite terrace. We show an evolution through time as follows: (1) restricted marine sedimentation during the Early Cretaceous after the initial break-up, with slope progradational clinoforms and hemipelagite drape developed; (2) open marine sedimentation characterized by the onset of alongslope sedimentary processes during the Late Cretaceous and development of a contourite depositional system; (3) downslope gravity processes dominated sedimentation during the Paleocene-Eocene, including development of a canyon and submarine fan; and (4) an alongslope contourite depositional system was re-established on the lower slope in the Middle Miocene, while turbidites (from a northern source) covered the Mozambique Basin. The Mozambique Fracture Zone marks a distinct and steep slope seaward of the contourite terrace, and has significantly influenced both contourite and turbidite deposition. Our study provides new insights into the onset and evolution of bottom current control on margin sedimentation, the interaction of downslope and alongslope processes and how these processes have jointly sculpted this part of the southern Mozambique margin.

根据新的地震反射数据，这项研究揭示了莫桑比克南部边缘马普托附近下坡阶地复杂沉积系统的发展。深水沉积系统清楚地显示了下坡和顺坡过程的相互作用。下坡特征包括：明显的峡谷，斜坡蠕变，海底滑坡和多阶段的大规模运输沉积物。坡度特征包括：轮廓线漂移和沉积波，侵蚀性护城河，山谷，侵蚀性表面和独特的轮廓线平台。我们显示出随时间的演变，如下：（1）初始破裂后白垩纪早期的海洋沉积受到限制，形成了斜向渐进的斜斜形和半铁矿悬垂性；（2）开放的海洋沉积，其特征是晚白垩世沿斜坡沉积过程的开始以及轮廓线沉积系统的发展；（3）在古新世-始新世期间，下坡重力作用主导了沉积，包括峡谷和海底扇的发展；（4）在中新世中下斜坡上重新建立了一个沿斜坡的轮廓岩沉积体系，而浊积岩（来自北部）覆盖了莫桑比克盆地。莫桑比克断裂带标志着异形岩阶地的一个陡峭的斜坡向海，并显着影响了异形岩和浊积岩的沉积。我们的研究为边际沉降中底部电流控制的发生和发展提供了新的见解，