An attempt has been made to construct the lithostratigraphic and biostratigraphic
characters of the Upper Cretaceous-Lower Eocene rocks exposed at Gebel Duwi and
Gebel Atshan sections, central Eastern Desert. Lithostratigraphically, the studied
succession arerepresented by four rock units arranged from base to top as: Dakhla,
Tarawan, Esna and Thebes formations.
Detailed study of planktonic foraminifera and calcareous nannofossils has led to
the recognition of forty five calcareous nannofossil and thirty one planktonic
foraminiferal species. Twelve planktonic foraminiferal biozones, Racemiguembelina
fructicosa Subzone (CF4), Pseudoguembelina hariaensis Subzone (CF3),
Pseudoguembelina palpebra Subzone (CF2), Parasubbotina pseudobulloides Subzone
(P1a), Praemurica uncinata Zone (P2), Morozovella angulata Zone (P3, subdivided
intoIgorina pusilla Subzone P3a and Igorina albeari Subzone P3b), Globanomalina
pseudomenardii Zone (P4), Morozovella velascoensis Zone (P5), Acarinina sibaiyaensis
Zone (E1), Pseudohastigerina wilcoxensis-Morozovella velascoensis Zone (E2),
Morozovella marginodentata Zone (E3) and Morozovella Formosa Zone (E4) have been
recognized as well as twelve calcareous nannofossil biozones; Micula murus Subzone
(CC25c), Micula prinsii Subzone (CC26b), Cruciplacolithus tenuis Zone (NP2),
Ellipsolithus macellus Zone (NP4), Fasciculithus tympaniformis Zone (NP5), Heliolithus
kleinpellii Zone (NP6), Discoastermohleri Zone (NP7/ NP8), Discoaster multiradiatus
Zone (NP9), Tribrachiatus contortus Zone (NP10) and Discoaster binodosus Zone
(NP11).
The Cretaceous/Paleogene (K/Pg) boundary is marked by the absence of
nannoplankton NP1 Zone and the planktonic (P0 and P1 Zones). The K/Pg boundary is
located at the top of CC26b. This boundary lies in the middle part of the Dakhla
Formation. The Danian/Selandian boundary can be placed inthe uppermost part of Zone
NP4 and nearly at the top of P3a Subzone in the upper part of the Dakhla Formation. The
Selandian/Thanetian boundary can be drawn at NP6/ NP7/8 zonal boundary, and the
upper part of P4 Subzone within the Esna Formation. The Paleocene/Eocene (P/E)