Santonian black shale sequences on the Demerara Rise, South American margin, Organic Geochemistry 37, pp 1816–1830. External links GeoWhen Database - Coniacian Late Cretaceous timescale, at the website of the subcommission for stratigraphic information of the ICS Stratigraphic chart of the Late Cretaceous, at the website of Norges Network of offshore records of geology and stratigraphy 03 Geological ages Cretaceous geochronology