The continental margin of Catalonia and Balearic Islands comprises three main types differentiated on the basis of seismic lines coupled with bottom samples. The progressive margin is located in the studied areas at the southern end of the Lion Gulf and in most of the Valencia GuIf. This type is characterized by wide and smooth shelf, rather unifol1ll slope with restricted development of submarine canyons, and tbick base-of-slope sedimen,\¡Iry units. The intermediate type presents the most" variable morphologic feanires in the provinces of the margin and mark(:d steplike physiography on the slope. This structural type is representative of many Balearic sectors and locally along the Costa Brava. Submarine canyons are best developed in tbis margin, together with highly variable unconsolidated sediment sequence of Plio-Quaternary that covers the acoustic basement. The abrupt type defmes the prominentslopes in the southern Balearic sector. This margin is the steepest and is found on the slope and ona reduced revel in (he other provinces of the margino