Integrated stratigraphy of the Oxfordian global stratotype section and point (GSSP) candidate in the Subalpine Basin (SE France)

摘要: An integrated biostratigraphic approach, based on ammonites, calcareous nannofossils, dinoflagellates, combined with sedimentology, carbon-isotope and physical stratigraphy, is proposed for the Subalpine Basin (Thuoux Saint-Pierre d'Argencon sections). Within expanded marl deposits of Terres Noires Fm., Callovian-Oxfordian boundary particularly well defined by ammonite taxa from different families (i.e. Cardioceratidae, Oppeliidae, Aspidoceratidae Perisphinctidae), nannoplankton (first occurrence large-sized Stephanolithion bigotii) dinoflagellate cysts Wanaea fimbriata). This precise biostratigraphy diversity ammonites permit long-range correlations Boreal Pacific domains. The exceptional outcrop conditions continuous sedimentation allow high-resolution chemostratigraphy cyclostratigraphy to be used. Variations δ13C record (1.5‰ increase during Lamberti Zone), consistent data other sections Paris Basin, provide additional markers characterise boundary. Promising results should serve constrain duration units thus improve Late Jurassic Geologic Time Scale. Comparisons are made two candidates an Oxfordian GSSP, Redcliff Point (UK) Dubki (Russian Platform). Finally, advantages support proposal Thuoux as a suitable GSSP candidate base Stage.