The Oued Necham (ON) section (Kalâat Senan, central Tunisia) provides a well-exposed outcrop of a CampanianMaastrichtian series that consists essentially of chalky limestones (. the Abiod Formation) grading progressively to a marly unit (. the El Haria Formation). | Planktonic foraminiferal biostratigraphy and quantitative analysis during the CampanianMaastrichtian transition at the Oued Necham section (Kalâat Senan, central Tunisia)