Recent sedimentary events in the western Gulf of Lions (Western Mediterranean)

Analysis of very high-resolution data (3.5 kHz profiles and EM12D acoustic imagery) collected during the CALMAR (Catalono-Languedocian Margin cruise) (1997) highlighted the occurrence of two very recent, but previously unknow n erosional sedimentary events on the continental rise, between the Rhone F an and the Pyreneo-Languedocian Ridge. These events, preserved as unconform able, very thin lobes observable on acoustic imagery but not on 3.5 kHz ech o-soundings, relate to erosional processes linked to near-bottom currents t hat seem to characterize the Holocene hydrodynamical conditions in the deep Gulf of Lions. They follow a Pleistocene regime when gravity sedimentation dominated on the Gulf of Lions margin either through aggradational turbidi te deposition (Rhone Fan and Pyreneo-Languedocian Ridge), or through remobi lization of sediments by regional mass-movements processes. (C) 2001 Elsevi er Science B.V. All rights reserved.