Foraminiferal biostratigraphy and paleobathymetry of the Maastrichtian – Paleocene succession at the north Farafra Oasis, Western Desert, Egypt

The Upper Cretaceous–Paleogene successions are well exposed at the Farafra Oasis, Western Desert, Egypt. The studied succession is distinguished into three formations arranged from base to top: Khoman (Maastrichtian), Dakhla and Tarawan (Paleocene). The identification of foraminiferal association yielded 55 species (28 planktonic and 27 benthonic). Most of them are considered as important biostratigraphical markers, especially in the Tethyan Realm. Based on planktonic foraminifera, nine biozones are differentiated, the Globotruncana aegyptiaca Zone, Gansserina gansseri Zone, Contusotruncana contusa Zone, Parasubbotina pseudobulloides Zone, Subbotina triloculinoides Zone, Praemurica uncinata Zone, Morozovella angulata-Igorina albeari Zone, Igorina albeari - Globanomalina pseudomenardii Zone and Globanomalina pseudomenardii- Acarinina subsphaerica Zone. The Cretaceous/Paleogene boundary (K/P) lies at the boundary between the Khoman and Dakhla formations. The biostratigraphic framework points to the absence of the Abathomphalus mayaroensis Zone of Late Masstrichtian and Guembelitria cretacea (P0) and Parvularugoglobigerina eugubina (Pα) zones of Early Paleocene. Therefore, the K/P boundary starts with the sudden disappearance of all the Cretaceous genera such as Globotruncana, Globotruncanita, Hedbergella Archaeoglobigerina, Heterohelix, Gansserina and Contusotruncana, followed by the appearance of Danian species such as Parasubbotina pseudobulloides (Plummer), Subbotina triloculinoides (Plummer) and Praemurica uncinata (Bolli). An attempt to estimate the paleobathymetry is done based on the investigated foraminiferal assemblages.