Foraminifera study for the characterization of the Campanian/Maastrichtian boundary in Gebel Owaina, Nile Valley, Egypt

The present work aims to provide a high-resolution stratigraphic range of the planktic foraminiferal group during the Campanian/Maastrichtian boundary (C/M) of Gebel Owaina, Nile Valley. We use the base of Planoglobulina acervulinoides (CF7c Subzone) to mark the C/M boundary, where the planktic foraminiferal assemblages in the subzone are proposed as indicative of the early Maastrichtian age. Five zones (CF9-CF5) and three subzones (CF8a, CF8b, and CF8c) were recognized in the present study. A morphogroups scheme for the calcareous benthic foraminifera used in this work comprises five morphogroups, observed in the Owaina section. Three planktic morphogroups can be recognized and indicate open marine conditions with a good connection to the Tethys Ocean due to the highly diverse Maastrichtian assemblage and high P/B ratio (% P > 95).