Geology of Dakhla Oasis, Western Desert, Egypt
37
East
West
Baris Mudstone Member
Mawhoob Shale Member
Kharga Shale Member
Qur El-Malik Sandstone Member
Tarawan FormaƟon
0
0
50 m.
25
5 10KM
Datum --Fig. 6 Generalized section across Edmonstone—Abu Minqar area (after Mansour et al. 1982)
formation consists of phosphate beds interbedded in alternating claystone, sandstone,
glauconitic sandstone, siltstone and conglomeratic phosphate.
The total thickness is about 20 m, and the upper part is marked by the presence of
about 0.5 m. of greyish white limestone capped with about 0.5 m. of hard pink limestone bed rich in Isocardia khargensis sp. (Abbas and Habib 1971), forming the top
surface of the formation and the top of the pediment bounding the Dakhla depression.
The Duwi Formation is highly fossiliferous with Inoceramus regular is Pervenguier,
Roudaireia drui Munier-Chalmas, Roudaireia dakhlensis Abbas, Lopha villei Coqu
and, Chark teeth and bone fragments and others. The fossil assemblage suggests a
lower Maestrichtian age. It is possible to conclude that the Duwi Formation in the
Dakhla basin was deposited in continuity with both Quseir and Dakhla Formations
of the Campanian age.
3.2.3 The Dakhla Formation
According to Said (1962) who initially applied the term, “Dakhla Shale” to 230 m
thick section of shales and mudstones layers overlying the Duwi Formation and
underlying the Tarawan Formation (Fig. 5). It can be divided into three units according
to Awad and Ghobrial (1965): Kharga Shale Member at the top (115 m. thick), Baris
Oyster Mudstone Member at the middle (135 m. thick), and Mawhub Shale Member
at the base (70 m. thick).
The Mawhub Shale Member forming the lower one overlies the Duwi Formation
and underlies the Baris Oyster Mudstone Member of the same formation. It consists
of grey to black fissile calcareous silty shale’s inerbedded with siltstone. It is assigned
to the early Maastrichtian age based on its foraminiferal content.
37
East
West
Baris Mudstone Member
Mawhoob Shale Member
Kharga Shale Member
Qur El-Malik Sandstone Member
Tarawan FormaƟon
0
0
50 m.
25
5 10KM
Datum --Fig. 6 Generalized section across Edmonstone—Abu Minqar area (after Mansour et al. 1982)
formation consists of phosphate beds interbedded in alternating claystone, sandstone,
glauconitic sandstone, siltstone and conglomeratic phosphate.
The total thickness is about 20 m, and the upper part is marked by the presence of
about 0.5 m. of greyish white limestone capped with about 0.5 m. of hard pink limestone bed rich in Isocardia khargensis sp. (Abbas and Habib 1971), forming the top
surface of the formation and the top of the pediment bounding the Dakhla depression.
The Duwi Formation is highly fossiliferous with Inoceramus regular is Pervenguier,
Roudaireia drui Munier-Chalmas, Roudaireia dakhlensis Abbas, Lopha villei Coqu
and, Chark teeth and bone fragments and others. The fossil assemblage suggests a
lower Maestrichtian age. It is possible to conclude that the Duwi Formation in the
Dakhla basin was deposited in continuity with both Quseir and Dakhla Formations
of the Campanian age.
3.2.3 The Dakhla Formation
According to Said (1962) who initially applied the term, “Dakhla Shale” to 230 m
thick section of shales and mudstones layers overlying the Duwi Formation and
underlying the Tarawan Formation (Fig. 5). It can be divided into three units according
to Awad and Ghobrial (1965): Kharga Shale Member at the top (115 m. thick), Baris
Oyster Mudstone Member at the middle (135 m. thick), and Mawhub Shale Member
at the base (70 m. thick).
The Mawhub Shale Member forming the lower one overlies the Duwi Formation
and underlies the Baris Oyster Mudstone Member of the same formation. It consists
of grey to black fissile calcareous silty shale’s inerbedded with siltstone. It is assigned
to the early Maastrichtian age based on its foraminiferal content.