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Stratigraphy, sedimentology and tectonic evolution of the Upper Cretaceous/Paleogene succession in north Eastern Desert, Egypt

Research Authors
Abdalla M. El Ayyat ⇑, Nageh A. Obaidalla
Research Abstract

The stratigraphy, sedimentology and syn-depositional tectonic events (SdTEs) of the Upper Cretaceous/
Paleogene (K–P) succession at four localities in north Eastern Desert (NED) of Egypt have been studied.
These localities are distributed from south-southwest to north-northeast at Gebel Millaha, at North
Wadi Qena, at Wadi El Dakhal, and at Saint Paul Monastery. Lithostratigraphically, four rock units have
been recorded: Sudr Formation (Campanian–Maastrichtian); Dakhla Formation (Danian–Selandian);
Tarawan Formation (Selandian–Thanetian) and Esna Formation (Thanetian–Ypresian). These rock units
are not completely represented all over the study area because some of them are absent at certain sites
and others have variable thicknesses. Biostratigrapgically, 18 planktonic foraminiferal zones have been
recorded. These are in stratigraphic order: Globotruncana ventricosa Zone (Campanian); Gansserina gansseri,
Contusotruncana contusa, Recimguembelina fructicosa, Pseudohastigerina hariaensis, Pseudohastigerina
palpebra and Plummerita hantkenenoides zones (Maastrichtian); Praemurica incostans, Praemurica uncinata,
Morozovella angulata and Praemurica carinata/Igorina albeari zones (Danian); Igorina albeari, Globanomanlina
pseudomenradii/Parasubbotina variospira, Acarinina subsphaerica, Acarinina soldadoensis/
Globanomanlina pseudomenardii and Morozovella velascoensis zones (Selandian/Thantian); and Acarinina
sibaiyaensis, Pseudohastigerina wilcoxensis/Morozovella velascoensis zones (earliest Ypresian). Sedimentologically,
four sedimentary facies belts forming southwest gently-dipping slope to basin transect have
been detected. They include tidal flats, outer shelf, slumped continental slope and open marine hemipelagic
facies. This transect can be subdivided into a stable basin plain plus outer shelf in the extreme
southwestern parts; and an unstable slope shelf platform in the northeastern parts. The unstable slope
shelf platform is characterized by open marine hemipelagic, fine-grained limestones and fine siliciclastic
shales (Sudr, Dakhla, Tarawan and Esna formations). The northeastern parts are marked by little
contents of planktonic foraminifera and dolomitized, slumped carbonates, intercalated with basinal
facies. Tectonically, four remarkable syn-depositional tectonic events (SdTEs) controlled the evolution
of the studied succession. These events took place strongly within the Campanian–Ypresian time interval
and were still active till Late Eocene. These events took place at: the Santonian/Campanian (S/C)
boundary; the Campanian/Maastrichtian (C/M) boundary; the Cretaceous/Paleogene (K/P) boundary;
and the Middle Paleocene–Early Eocene interval. These tectonic events are four pronounced phases
in the tectonic history of the Syrian Arc System (SAS), the collision of the Afro-Arabian and Eurasian
plates as well as the closure of the Tethys Sea.

Research Department
Research Journal
Journal of African Earth Sciences
Research Rank
2
Research Year
2013
Research Pages
pp. 35–59