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A new morphosedimentary map of the Gulf of Cadiz is presented, showing the contourite depositional system on the gulf's middle slope. This map is constructed from a broad database provided by the Spanish Research Council and the U.S. Naval Research Laboratory. Our map shows that this contourite depositional system comprises five morphosedimentary sectors: (1) proximal scour and sand ribbons; (2) overflow sedimentary lobe; (3) channels and ridges; (4) contourite deposition; and (5) submarine canyons. The Gulf of Cadiz contourite depositional system stems directly from the interaction between Mediterranean Outflow Water and the seafloor; its morphosedimentary sectors are clearly related to the systematic deceleration of the Mediterranean Outflow Waters westward branches, bathymetric stress on the margin, and the Coriolis force. The slope's depositional system can be considered as a mixed contourite and turbidite system, i.e., a detached combined drift and fan.

International audienceThe study of more than 500 single- and multi- channel seismic records enabled the generation of a detailed palaeo-bathymetric map of the Messinian surface over most of the Alboran Basin, Western Mediterranean. This regional surface is characterized by several erosional features (channels, terraces and canyons) and topographic highs (structural, volcanic and diapiric in origin). The most prominent feature is the incised Zanclean Channel crossing the entire basin, its entrenchment having been associated with the opening of the Strait of Gibraltar and subsequent inflow of Atlantic waters. The incision depth of the channel is variable, suggesting local variations in the erosive capacity of the Atlantic inflow, conditioned mainly by the regional basin topography and the local presence of topographic highs. Adjacent to this channel along the Spanish and Moroccan margins, and near the Strait of Gibraltar, several submarine terraces developed at different depths suggest a pulsed flooding of the Alboran Basin. There could have been two major inflow phases of Atlantic water, one shortly before and another during the Zanclean flooding, the latter accompanied by periods of relative sea-level stillstands that enabled terrace development. Alternatively, these features were all generated during the main flooding evident and subsequent pulsed infilling of the basin

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