Calcareous nannofossil biostratigraphy of the uppermost Maastrichtian–lower Paleocene at the Misheiti section, East Central Sinai, Egypt

Calcareous nannofossil data, δ13C and δ18O values, and carbonate contents of the uppermost Maastrichtian–lower Paleocene succession cropping out at the Misheiti section (East Central Sinai, Egypt) have been used to denote and reveal the changes across the Cretaceous/Paleogene (K/Pg) boundary. The study interval belongs to the uppermost Sudr Formation and the Dakhla Formation. Four calcareous nannofossil zones (Micula prinsii, NP1, NP2/3, and NP4) were recognized. The δ13C profile and the carbonate content show significant decreases across the K/Pg boundary. A hiatus at the K/Pg boundary is indicated by the absence of the basal part of Zone NP1. Geochemical results and calcareous nannofossil assemblages reflect fluctuations of the paleotemperature during the latest Maastrichtian–early Paleocene.