El cañón de Portimao y su relación con los depósitos contorníticos del margen continental del Algarve (Portugal)

Abstract

The Portimao canyon, placed in the southern Portugal continental margin, is a good example to study the relationship between the downslope sedimentary transport from the continental shelf to deep basin as well as the a long slope sedimentary transport induced by oceanic contour currents. Submarine canyons are interpretad as a sedimentary pathway between the shelf and the deep basin along the slope. A particular pattern is developed in the Gulf of Cadiz where a complex distribution of canyons, valleys and gulies it seem to be linked to the contourite drifts bodies generated under the influence of the Mediterranean Outflow Waters (MOW) at intermediate deeps. The head of the Portimao canyon occurs near the shelfbreak at a depth of 110 m and its intersection with the contourite drift occurs at intermediate deeps of 700 to WOO m. The sedimentary structure of the canyon walls, infered from the Inflexion of the conturite reflectors into the canyon, as well as the end of the Alvarez Cabral Deep into the Portimao canyon, seems to indicate the role of Portimao canyon as a source of feeding the Horseshoe abisal plain with contour sediments.