Stratal patterns, sediment composition, and sequence stratigraphy at the margin of the Vercors carbonate platform (Lower Cretaceous, SE France)

Conventional sequence-stratigraphic concepts relate the largescale stratal architecture of sediment bodies to changes in relative sea level. This paper evaluates the relationship between stratal geometry and sea level stand, based on a study of large, semicontinuous outcrops of Cretaceous carbonate platform strata in the Vercors (southeastern France). Multiple lines of evidence for sea-level change are combined, including stratal geometry, detailed quantitative microfacies analyses, and diagenetic patterns at platform-top hardground surfaces. This study shows that stratal geometries alone are a rather ambiguous guide to sea-level history. Without the accompanying sedimentologic and diagenetic evidence for sea-level change, most of the stratal architecture of the Vercors platform can be explained by either changes in accommodation or changes in carbonate production. -from Authors