Correlation between onshore and offshore Pliocene-Quaternary systems tracts below the Roussillon Basin (eastern Pyrenees, France)

The western part of the Gulf of Lions was chosen for conducting the first correlative studies between the terrestrial Pliocene-Quaternary sedimentary formations (Roussillon Basin) and their extension on the adjacent continental shelf. The work was based on a study of 32 wells drilled onshore and Elf Aquitaine seismic lines offshore. The correlations are based on equivalence between the two domains in terms of stacking patterns, biostratigraphy and geometry. The post-Messinian sedimentation within the study area is characterised by eight equivalent-order stacking patterns represented by eight dominantly prograding systems tracts. Furthermore, comparison of the spatial positions of offlap breaks on several seismic profiles provides a better understanding of the roles of tectonism, eustasy and sedimentary supply in the stacking of the identified sequences.