An unusual erosional surface has been identified on seismic data from the outer shelf on the northern Namibian margin. The undulating surface defines a depression extending for 1300 km² from which fine-grained Miocene sediments have been excavated to a depth of up to 160 m. The depression has a kidney-shaped planform, with three deep pits marking its basinward extent. It is an entirely closed feature, with no evident channels feeding in or leading out. Subsequent sedimentation has completely filled in the depression with the earliest infilling units exhibiting unusual depositional geometries. Well correlation yields a date of 9.9 ± 1.0 Ma for the erosional surface. No analogous features are known, but of all the possible causal mechanisms, it is considered most likely that the erosional depression was created by the extraordinary action of eddying bottom currents. These were probably associated with the well-documented Late Miocene onset of intensification of the Benguela Upwelling System, and were possibly directed by a small local variation in sea bed relief.

根据纳米比亚北部边缘外大陆架的地震数据，发现了一个不寻常的侵蚀面。起伏的表面定义了一个延伸 1300 km ²的洼地从中新世细粒沉积物已被挖掘至 160 m 的深度。洼地呈肾形，三个深坑标志着其向盆地延伸。它是一个完全封闭的特征，没有明显的通道进出。随后的沉积完全填满了凹陷，最早的充填单元表现出不寻常的沉积几何形状。井相关产生侵蚀面的日期为 9.9 ± 1.0 Ma。没有已知的类似特征，但在所有可能的因果机制中，人们认为侵蚀洼地最有可能是由涡流底部水流的异常作用造成的。这些可能与有据可查的中新世晚期本格拉上升流系统加强有关，