Abstract:
In the Upper Paleocene - Lower Eocene succession of Gebel
Gurnah two formationa are recognised which are separated bY a minor
disconformity. The Owaina Formation of Upper Paleocene age is represented by the topmost part of the Upper Owaina-Shale Member.
The Thebes Formation of Lover Eocene age is represented by a lower
Thebes Calcareous Shale Member and an upper Thebes Limestone Member.
The detailed study of the planktonic Foraminifera has led to
the description of ninety species, subspecies and varieties; thirteen species and subspecies of which are new. The planktonic foraminiferal genera Guembelitrin, Chiloguembelina and Globanomalina are described for the first time in this locality.
Six planktonic foraminiferal zones are recognised in the
present sequence. The Globorotalia velascoensis zone is of Upper
Paleocene age and coincides with the Upper Owaina Shale Member. The Globorotalia aequa, G. subbotinae, G. formasoformosa, G. aragonensis and G, "palmerae" zones are of Lower Eocene age and coincide with
Thebes Formation. The detailed study of the planktonic Foraminifera with the six
zones established in the present succession make an excellent basis
for inter-regional and inter-continental correlation with similar
planktonic zonations in many parts of the world.
A careful study of the larger fossil Foraminifera has also
been carried out. Nine species, subspecies and one variety are
described. One species and one variety of the genus Operculina are described as new. The larger fossil Foraminifera are restricted to
Rock Units IV and V of the Thebes Limestone Member. A numerical analysis of the foraminiferal population in the
lower shaly part of the succession has led to a number of very
important conclusions concerning frequency in relation to sediment and
ratios of selected taxa.
