Integrated Platform/Basin Biostratigraphy of the Upper Cenomanian-Lower Turonian in Provence (SE France)

Recent studies on Upper Cenomanian-Lower Turonian outcrops from Cassis area allow to build a biolithostratigraphic framework from platform (La Bedoule section) to basin deposits (Cassis section), based on ammonites, planktonic foraminifera, inoceramids, rudists and ostracods. Four ammonite Zones are documented: the Late Cenomanian Geslinianum and Juddii Zones; the Early Turonian Nodosoides and, possibly, the Middle Turonian Woollgari Zones. The latest Cenomanian Scottii and the earliest Turonian Coloradoense Zones have not been identified. At Cassis, all the three planktonic foraminifera zones of the Upper Cenomanian and the Lower Turonian are identified: the Cushmani, Archaeocretacea and Helvetica zones. For the first time in the study area, a biozonation based on inoceramids is established while the ostracod biozonation is improved. The rudist scale is calibrated with the ammonite one through stratigraphic correlation between platform and basin successions. A detailed study of facies geometry leads to a sequence stratigraphic interpretation of systems tracts both of carbonate platform and basin settings. Finally, the Cassis section is compared with the Pueblo section and proposed as a reference section for the Cenomanian/Turonian boundary. (C) 2001 Editions scientifiques et medicales Elsevier SAS.