2. The Palaeozoic outcrops of north Eastern Desert

ABDALLAH & EL-ADINDANI (1965) subdivided these rocks into three formations, from top to base:

- Aheimer Formation. - Abu Darag Formation, and - Rod El Hamal Formation.

The three formations have unexposed bases and their exact superposition is therefore unknown. According to SAID & EISSA (1969), these formations seem to be stratigraphically the same in spite of the variations of the foraminiferal faunal assemblage found in each. The exposures range in age from Late Carboniferous to Early Permian.

Rod El Hamal Formation: (100-357 m, Carboniferous)

It is best exposed at the junction of Wadi Araba and Wadi Rod El Hamal and is composed of the following mappable units "members"

Abu Darag Formation: (40-178 m, Upper Carboniferous)

The most complete section of the Abu Darag Formation is exposed at the core and southern flank of the Abu Darag anticlinal structure. In the northern and southern flanks, the formation is overlain by sandy and red beds (Qiseib Formation) which are intercalated with marine thin beds of green marls and yellow hard limestones of Permo-Triassic age.

Aheimer Formation: (60-250m, Upper Carboniferous-Lower Permian)

The type locality of this formation is at Wadi Aheimer about 10 kms south of Ain Sukhna. This formation could be subdivided into three members as follows (KORA & MANSOUR 1992).

In the north Eastern Desert between Wadi Qena and Wadi Dakhel at the Southern Galala Plateau, Carboniferous strata are designated the Somr El-Qaa Formation (KLITZSCH 1990). This unit (40-60 m) most probably correlates with the Um Bogma and Abu Thora Formations of Sinai, but marine influence is less than at Sinai (KORA 1995).

3. The Palaeozoic subsurface rocks in north Western Desert:

A formal startigraphic scheme was proposed by KEELEY (1989) for this Palaeozoic succession. Two groups and seven formations span the interval from the Mid-Cambrian to the Early Permian. The resolution between these superficially similar clastic-dominated units is enhanced by the use of palynostratigraphical zonation.

The Siwa Group (Mid-Cambrian-Late Silurian)

i) Shifa Formation (after the spring Ain Shifa at Siwa)ii) Kohla Formation (after Kohla area, north of Siwa)iii) Basur Formation (after the type well El-Basur-1)

The Faghur Group (Devonian-Early Permian)

Zeitoun Formation (after the type well Zeitoun-1)ii) Desouqy Formation (after the type well El-Desouqy-1iii) Dhiffah Formation (after the Dhiffah Plateau on the northern Libyan border)iv) Safi Formation (after the spring Ain es Safi at Siwa)