Stratigraphic simulations of the shelf of the Gulf of Lions: Testing subsidence rates and sea-level curves during the Pliocene and Quaternary

Abstract : Determining the relative importance of factors interacting to control stratigraphic organization is a key issue in sedimentology. The Pliocene-Quaternary chronostratigraphy on the Gulf of Lions platform is still poorly constrained, giving rise to different interpretations of the evolution of its subsidence through time. This paper examines the Pliocene-Quaternary sedimentary filling of the Gulf of Lion's shelf with Dionisos, a numerical stratigraphic model. Our results show that a constant subsidence rate accurately reproduces the observed geometries, whereas a varying subsidence rate reproduces them only if the acceleration of subsidence is limited. At this time-scale, a third-order eustatic curve is also reappraised: a higher resolution curve (built using δ18O measurements) gives a more realistic restitution of our stratigraphic markers. Finally, the constant subsidence rate and sediment fluxes implied in these modellings are discussed relative to climate and local factors of sedimentation.