Morphology of turbidite systems within an active continental margin (the Palomares Margin, western Mediterranean)

The Palomares Margin, an NNE–SSW segment of the South Iberian Margin located between the Alboran and the Algerian–Balearic basins, is dissected by two major submarine canyon systems: the Gata (in the South) and the Alías–Almanzora (in the North). New swath bathymetry, side-scan sonar images, accompanied by 5 kHz and TOPAS subbottom profiles, allow us to recognize these canyons as Mediterranean examples of medium-sized turbidite systems developed in a tectonically active margin. ta Turbidite System is confined between residual basement seamounts and exhibits incised braided channels that feed a discrete deep-sea fan, which points to a dominantly coarse-grained turbiditic system. The Alías–Almanzora Turbidite System, larger and less confined, is a good example of nested turbiditic system within the canyon. Concentric sediment waves characterize the Alías–Almanzora deep-sea fan, and the size and acoustic character of these bedforms suggest a fine-grained turbidite system. Both canyons are deeply entrenched on a narrow continental shelf and terminate at the base of the continental slope as channels that feed deep sea fans. While the Alías–Almanzora Turbidite System is the offshore continuation of seasonal rivers, the Gata Turbidite System is exclusively formed by headward erosion along the continental slope. In both cases, left-lateral transpressive deformation influences their location, longitudinal profiles, incision at the upper sections, and canyon bending associated with specific fault segments.