Resumen de Influencia de los cañones submarinos sobre la progradación de la plataforma continental
Francisco José Lobo Sánchez, Michel Tesson, Francisco Javier Hernández Molina, Luis Somoza, Víctor Díaz del Río Español
Seismic stratigraphic analysis conducted on the Cult' of Cadiz and Gulf of Lions continental shelves are used to determine the relative importance of submarine canyons on the sedimentary building and progradation of such marine domains. In the Gulf of Cadiz, thick regressive wedges attributed to marginal deposits as deltaic complexes and littoral wedges are generated during periods of sea level lowering and low sea levels, when the locus of sedimentation sihfted to the upper slope. The final process is the seaward migration of the shelfbreak evidenced by the progradational stacking pattern exhibed by the wedges. In contrast, in the Gulf o f Lions shelf sedimentary deposits of similar origin generally show abrupt terminations near the shelfbreak, indicating that probably most of the sediments deposited on the upper slope during sea level lowstands were removilized and transported downslope. The influence o f the submarine canyons that affect this shelf (Lacaze-Duthiers and Aude canyons) is proposed, because they probably received most of the sediments supplied during that intervals and controlled the sedimentary transference from the outer shelf to deeper domains. The consequence is the relatively poor displacement of the shelfbreak during the deposition of regressive deposits.
