الفهرس 
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Abstract
The present study deals with benthic foraminifera of the Maastrichtain
and Early Eocene rocks of the Farafra Oasis, central part of the Western Desert, Egypt. This study
was achieved by measuring two stratigraphic sections in the study area; one in Gebel Northren Gunna
and the other in Gebel El-Quss Abu Said. The stratigraphic study subdivided the Maastrichtain and
Early Eocene succession into five rock units; Khoman Chalk, Dakhla Shale, Tarawan Chalk, Esna Shale
and Farafra Limestone.
The paleontologic study included the identification of 254 spp. of benthic foraminifera in the
recognized rock units. Through the spread and distribution of the benthic foraminifera species, six
time markers were recorded and correlated with the standard planktonic biozones. These time markers
are: Spiroplectammina knebeli for lower part of Khoman Chalk (Middle Maastrichtian), Bolivinoides
draco draco for the upper part of Khoman Chalk (Late Maastrichtian), Lagena hispida –
Spiroplectammina dentata for Dakhla Shale (Early Paleocene), Gavelinella rubiginosa -
Spiroplecammina dentata for the Tarawan Chalk (Middle Paleocene), Loxostomoides applinae -
Vulvulina colei for the lower part of Esna Shale (Late Paleocene) and Marginulina wetherellii zone
for the upper part of Esna Shale (Early Eocene). Also, eight larger benthic foraminiferal species
were recorded in the Latest Paleocene-Early Eocene interval; Nummulites deserti, N. fraasi. N.
solitaries, Alveolina decipiens, A. pasticillata, Operculina libyca, Assilina farafraensis and
Discocyclina nudimargo.
The paleoecologic study included the calculation and representation of different parameters; the
total number of foraminiferal species, the total number of small benthic foraminifera, the total
number of planktonic foraminifera and the planktonic / benthic ratio. The interpretation of these
parameters revealed an open marine environment with a decrease in the sea water depth in the lower
part of Khoman Chalk and an increase in the sea water depth in the middle and upper parts of Khoman
Chalk. The obtained results for the Dakhla Shale and Tarawan Chalk reflect the continuing of open
marine conditions with a relatively shallow environment. In the lower part of Esna Shale, it was
noticed a decrease in
the sea water depth due to the flooding occurrence of larger benthic
foraminifera; Nummulites deserti, N. fraasi, N. solitarius and Alveolona pasticillata. These larger
benthonic foraminifera contributed to a great extent in shallowing sea water during the Latest
Paleocene-Early Eocene time. These shallow conditions were followed by an increase in the faunal
content indicating to a relatively deeper environment at the end of the lower part of Esna Shale.
These open marine conditions decrease gradually in the middle and upper parts of Esna Shale,
reflecting a decrease upwardly in the sea water depth till the Farafra Limestone which represents a
shallow carbonate deposition.
The microfacies analysis revealed that Khoman Chalk is dominated by wackestone facies which graded
upward to less dominated packstone facies. The Dakhla Shale consists mainly of highly calcareous
shale facies with intercalations of highly argillaceous limestone (packstone). The Tarawan Chalk
made up of wackestone/packestone facies which graded upward at El-Quss Abu Said Section to
packstone facies. Esna Shale consists mainly of highly ferruginous calacreous shale facies with
intercalation at its lowermost part of highly argillaceous wackestone (Northern Gunna section) and
grainstone with less dominant packstone (El-Quss Abu Said Section). Meanwhile, the uppermost part
of Esna Shale at El-Quss Abu Said Section is intercalated with dolomitic wackestone and packstone.
The Farafra Limestone is dominated by the wackestone facies which graded downward to less dominated
grainstone facies at Northern Gunna section. At El-Quss Abu Said Section the Farafra Limestone made
up of dolomitic packstone which intercalated with wackestone/packstone. The facies zones of the
studied microfacies graded from deep sea to deep shelf and deep shelf margin during deposition of
Khoman Chalk and Dakhla Shale. These facies zones were repeated during deposition of Tarawan Chalk
and Esna Shale. The open marine platform was the facies zone during deposition of Farafra
Limestone.