Lithostratigraphy, Stable Isotope Stratigraphy and Calcareous Nannofossils Biostratigraphy of the Danian-Thanetian at Nukhul, Sinai, Egypt

Paleocene sediments exposed at Nukhul, Sinai, Egypt were subjected to a detailed calcareous nannofossil biostratigraphy besides tracking changes in carbonate contents, δ13C and δ18O values. This Paleocene outcrop extends through the Dakhla - Tarawan formations. About 8.5 m of Dakhla F. consists of grey calcareous shale, and 2 m from the Tarawan F. consists of yellowish argillaceous limestone were investigated. Five calcareous nannofossil zones (NP2/3 - NP7/8) were delineated. The Late Danian Event was traced at a level characterized by an abrupt decrease in carbonate content and δ18O values, and minimum values of calcareous nannofossil’s diversity and abundance that support warming conditions during this interval. The boundary between Danian and Selandian was placed in coincidence with the base of Zone NP5. No remarkable changes in lithology or in δ13C and δ18O values were noted close to this boundary except an abrupt drop in δ18O values just below it and increase in δ13C values slightly above this level. A distinct drop in carbonate content and calcareous nannofossil diversity was documented close to this boundary indicating warming episode. Calcareous nannofossils indicate a hiatus within Danian at Nukhul. The Selandian/Thanetian boundary was placed in coincidence with the base of NP7/8 combined Zone. No remarkable change in lithology, calcareous nannofossil assemblage, or δ13C and δ18O values were recorded across this boundary except the sudden drops in δ13C and δ18O values slightly below and above it. Calcareous nannofossils, δ13C and δ18O data reflect an upward increase in paleotemperature throughout the Paleocene at Nukhul.