Seismic expression of turbidity-current and bottom-current processes on the Northern Mauritanian continental slope

Abstract

AbstractThe architectural framework of the Mauritanian continental slope is characterized by a complex mixture of gravity and bottom current deposits that modify the pelagic background sedimentation. Since the Neogene, the Mauritanian passive margin bottom-currents have been the main control on the construction and topography of the slope. On the lower slope, numerous sediment waves and contourites occur. Turbidity-current channel incisions and slope failures are responsible for the destructive remodelling of the slope. The upper-slope incisions have a dendritic pattern, and converge into highly sinuous main channels in the lower slope, where the channels become constructional with levees and lateral accretion packages. Subsurface data exhibit older slope failures, which guide the location of later turbidity-current channel pathways. The seabed and shallow seismic expression of deep-water slope deposits generated by variable gravity-transport and bottom-current processes in offshore Northern Mauritania can be compared with analogous settings in lower resolution, deeper subsurface seismic data to gain a better understanding of the slope environment and deposits.