An overview of the Paleocene-Eocene calcareous nannofossil biostratigraphy and bioevents in Egypt

Faris, Mahmoud; Farouk, Sherif; Shabaan, Manal

Abstract

Nineteen Paleocene-Eocene calcareous nannofossil bioevents are used to identify the zones from NP1 to NP20. Several events and climatic changes are reported across the Danian/Selandian, the Selandian/Thanetian, the Paleocene-Eocene, Early Eocene/Middle Eocene, and Middle Eocene/Late Eocene stage boundaries. In Egypt, most of these boundaries are associated with hiatuses. The diachronic in the stratigraphical range of some calcareous nannofossil species are also revised in this work. The study offers some of the most important secondary events that have been used in Egypt. The lowest occurrences (LOs) of both Cruciplacolithus edwardsii and Neochiastozygus modestus are used to approximate the base of NP3 Zone, instead of Chiasmolithus danicus. The LO of Ellipsolithus distichus can be used to delineate the base of NP4 Zone, in case of the very rare and sporadic occurrence of Ellipsolithus macellus. The LO of Tribrachiatus orthostylus can be used to define the base of NP11 Zone. The LO of Reticulofenestra dictyoda can be used to approximate the base of NP13. The LO of Nannotetrina cristata defines the Early/Middle Eocene boundary. The LO of Discoaster martinii occurs near the base of NP15 and can be used tentatively to define the base of NP15. The LO of the Reticulofenestra umbilicus can be used to delineate the base of NP16. The LO of Reticulofenestra hillae first occurs near the NP16/NP17 zonal boundary and consequently can be tentatively used to define the base of the NP17 Zone. The HO of Chiasmolithus grandis is considered an unreliable event for the base of NP18, it last occurs near, close to, or at the base of NP18 in some Egyptian sections. The LO of Isthmolithus recurvus occurs within NP17 and considered a diachronous species.

Citation

Faris, M., Farouk, S., & Shabaan, M. (2021). An overview of the Paleocene-Eocene calcareous nannofossil biostratigraphy and bioevents in Egypt. In M. Montenari (Ed.), Stratigraphy & Timescales (225-292). Elsevier. https://doi.org/10.1016/bs.sats.2021.09.003

• Online Publication Date: Nov 10, 2021
• Publication Date: 2021
• Deposit Date: Jun 5, 2023
• Publisher: Elsevier
• Pages: 225-292
• Series Title: Calcareous Nannofossil Biostratigraphy
• Series ISSN: 2468-5178
• Book Title: Stratigraphy & Timescales
• Chapter Number: 3
• ISBN: 978-0-12-824624-5
• DOI: https://doi.org/10.1016/bs.sats.2021.09.003