Some evidences of northward fine sediment transport in the northern Portuguese continental shelf

On the basis of sedimentological and oceanographical data, a transport scheme for fine-grained material is proposed in order to explain the location of a muddy deposit present in the northern Portuguese continental shelf, north-west off the Douro River mouth. This mid-shelf deposit is recent, active and its main source is apparently the Douro River. The sediment supply can be related with the oceanographic conditions in winter regime, characterised by a poleward along shelf current with a bottom westward component, as a consequence of a south-west wind. The resulting fine sediment transport, essentially made in the bottom nepheloid layer is believed to have a north-west direction. (C) Elsevier, Paris.