southern Vercors, SE France)

A large area of synsedimentary collapse covering about 25 km2 has been iden-tified within lower Barremian carbonate platform strata of the southern Ver-cors (Vocontian Basin, SE France). New observations of the prograding/ aggrading strata of the Cirque d’Archiane and the Glandasse Plateau reveal the presence of a disturbed zone, showing tilted and imbricated blocks as well as slump features. Measurements and analysis on these synsedimentary dis-torted strata suggest that they compose a slide which slipped on the Barremian slope. The occurence of two coarse bioclastic grainstone beds on the eastern side of the Archiane Valley, in a distal hemipelagic context, sug-gests that this instability generated a tsunami that reworked proximal bioclas-tic material, previously transported out to the hemipelagic domain at the same time as the slide, rearranging it under the influence of tractive currents. The idea of high frequency sea-level variations to explain these strata is unlikely. They do not exhibit univocal sedimentologic evidence (such a