The Gulf of Lions and Cap de Creus Canyon area was selected by combined European and North American research teams for the study of continental margin sedimentary processes and history based on three important criteria. First, evidence of coastal flooding and shelf sediment transport during storms by combined wave and current stresses, and by turbulent flow in canyon heads due to cold sinking water masses all indicate a sedimentary system that is quite active at present. Sediment in the western Gulf originates from both the Rhône River, the major sediment source to the Gulf, and also from the smaller streams in the western Gulf—among them the Aude, Orb, Herault, and Têt. The relative importance of each of these sources is not well understood, nor are the transport processes that distribute sediment throughout the Gulf.

Second, the Gulf hosts a complex morphology of deltas, shelf lobes, canyons, and deep-sea deposits (Berne et al; 1997,2001, 2004) that provide a solid basis for interpreting past processes and comparing them with those of today (Alonso et al., 1991; Baztan et al., 2005). The rich fabric of the Gulf morphology attests multiple sea levels changes and, at times, extraordinary amounts of sediment delivered to the margin (Rabineau et al., 1998; Berné et al., 1999). Finally, the outer shelf and slope exhibit a remarkable record of these episodes of deposition and sea level change over the past 100,000 years or so (Lofi et al., 2003; Rabineau et al., 2005). The potential for connecting active sediment processes with a complex and well-preserved sedimentary record provides an exciting research opportunity.

The Cap de Creus Canyon ties in with all three of these criteria. Lying at the extreme western edge of the Gulf of Lions, the canyon is the distal site for sediment emanating from the Rhône and transported west along the shelf. The canyon heads close to the rugged coast of the Spanish Rio Bravo coast, and sediment not impounded by the coast is likely transported into the canyon. At positions of lower sea level, the canyon was a morphological trap for all bed load sediment transported westward. The CHIRP images presented here, as well as the recently acquired multi-beam data (courtesy of Fugro Survey Ltd. and AOA Geophysics Inc.) show patterns in morphology and sediment packages that attest to the role of the canyon in intercepting and channeling sediment to the deeper reaches of the Gulf. Thick sediment sequences near the head of the canyon record high quantities of sediment deposited at lower stands of sea level, similar in many ways to those to the east in the Gulf of Lions (Berné and Gorini, 2005; Schoolmeester et al. 2005). Shelf sediment is thicker on the east edge of Cap de Creus Canyon than on the west, indicating alongshore and alongshelf transport, probably during the latest rise in sea level (Grossman et al. 2005).