The data on the Iberian prodeltas was acquired in the frame of the Spanish projects PRODELTA (REN2002-02323). We thank captain and crew of R/V L’Atalante ­(campagne PRISME 2007) and funding from French ANR projects ISIS and DANACOR. Data for some areas of the continental shelf (Ter prodelta) were acquired by “Secretaría General del Mar” of the “Ministerio de Medio Ambiente, y Medio Rural y Marino” and provided free of charge. Borehole geotechnical data was acquired in the frame EC funded project PROMESS-1 (EVR1-CT-2002-40024). Hydrodynamic transects and instrumented moorings were funded by the Office of Naval Research, NICOP Grant N00014-02-1-0252. The “Generalitat de Catalunya” is acknowledged for support through an excellence research group grant (2009-SGR-146). J. Déverchère (UBO-IUEM, Brest) and K. Yelles (CRAAG, Algiers) are thanked for discussions about the Algerian shelf. Reviews by Homa Lee and Michele Rebesco greatly improved the submitted version of the manuscript

Most Mediterranean prodeltas show undulated sediments on the foresets of their Holocene wedges. These features have been described all along the Mediterranean and interpreted as either soft sediment deformation or, more recently, as sediment bedforms. We present a detailed analysis of these features using ultrahighresolution seismic and bathymetric data, as well as geotechnical information and hydrodynamic time series and hydrographic transects. We show that the characteristics of the sediment undulations (morphology and configuration of the reflections down section and between adjacent undulations) are incompatible with a genesis by sediment deformation

12 pages, 5 figures

Peer reviewed