LATE QUATERNARY SEDIMENTARY ENVIRONMENTS AND OSTRACODE ASSOCIATIONS ON THE RHODANIAN CONTINENTAL-SLOPE (WESTERN MEDITERRANEAN)

The study of sediments and of the ostracofauna of four cores, taken on the rhodanian continental slope, allows to reconstruct variations of palaeoenvironments during the last glacio-eustatic cycle. The relative chronology, attributed to the different facies, shows that they inter cept deposits going from the last glacial maximum until the Recent. Th e synthesis of analytic results conduit to the establishment of a sequ ence typical, dynamic and paleaoclimatic, constituted of three sedimen tary ensembles. These ensembles correspond respectively to a period of low sea level, to the transgressive interval and to a period of high sea level. Reworkings and the influence of the continental shelf are i mportant on the slope during glacial periods. Sedimentary environments are essentially controlled by the general circulation, that follows t he continental slope, and by the morphology of the margin characterize d by the indentation of canyons. Spatio-temporal variations of fauna o f ostracodes reflect both changes of the palaeoenvironment to the inte rface water-sediment, especially, eustatic variations, hydrodynamic co nditions and the climatical context. The conjunction of these two type s of approaches has allowed to give an interpretation of the evolution of the hydrosedimentary and morphostructural framework.