A re-description of the historical stratotype for the Berriasian Stage (Cretaceous System): Biostratigraphy and magnetostratigraphy

Abstract

The historical stratotype for the Berriasian Stage (Cretaceous System) at Berrias (Ardèche, France) is here re-assessed. It shows a sedimentary record of early to late Berriasian age, part of the pelagic limestone succession of the western Vocontian Basin. We describe a studied section, circa 30 m in thickness, which yields calpionellids, calcareous dinocysts, calcareous nannofossils, and ammonites. The magnetostratigraphy of the section is revised, and calibrated with the biostratigraphy of these fossil groups. Magnetozones M19n to M15r (including M16n.1r) are identified and matched to the calpionellid zonation, with the Alpina to Oblonga biozones represented.