Integrated biostratigraphy of two Upper Maastrichtian – Palaeocene successions in north-central Sinai, Egypt

Abstract

Integration of the calcareous nannofossil and planktonic foraminiferal biostratigraphies has been performed for theUpper Maastrichtian – Palaeocene successions at Gebel Umm Khushayb and west El-Hassana sections (north-centralSinai, Egypt). The studied successions include the uppermost part of the Sudr, Dakhla, and their lateral coeval Beida Formation. Biostratigraphic analysis has allowed recognition from Zone CF2 to Zone P4in terms of planktonic foraminifera and from Zone CC26c to Zone NP7/8 in terms of calcareous nannofossils. Maastrichtian/Palaeogene (K/Pg) boundary is characterized by an erosional surface that marks a hiatus between theSudr/Dakhla or Sudr/Beida formation boundaries, as confi rmed by the absence of the planktonic foraminiferal CF1to P1a zones and their equivalent nannofossil zones (top part of CC26c to lowest part of Zone NP3). Selandian (Da/Se) boundary lies in the upper part of the Dakhla Formation within the top of nannofossil Zone NP4,and within planktonic foraminiferal Zone P3b, similar to that of the Global Standard Stratotype-section and Point(GSSP) of the D/S boundary which has recently been chosen at the Zumaia section, northern Spain. was observed across the Selandian/Thanetian boundary as indicated by a lithological change and a very condensedZone NP6, corresponding to the Dakhla and Tarawan formation boundary in the west El-Hassana section. 

Keywords

• biostratigraphy, calcareous nannofossils, Danian/Selandian boundary, planktonic foraminifera, north-central Sinai.