The Eocene Thebes Formation had been subjected to detailed field and petrographic analysis to evaluate the stratigraphy, depositional facies, paleoenvironment and sedimentological history of the Thebes Formation carbonates. Four surface stratigraphic sections located in the Eastern Desert have been studied in detail. These sections are distributed from south to north: Gebel Hamadat, Wadi Syatin, Gebel Wasif, and Wadi Malha sections. The carbonate succession of Thebes Formation rests conformably on the siliciclastic shales of the Esna Formation at all sections except at Wadi Malha, where there is an unconformity separates between Esna and Thebes formations.
Sedimentologically, four sedimentary facies belts have been detected. These are tidal flats, bank, continental slope and open marine facies belts. The tidal flat facies are dominated by limemudstone with wackestone intercalations. Bank facies is composed mainly of intact and fragmented fine nummulites, gastropods, pelecypods, operculines, and echinoderm bioclasts. The nummulites bank is well represented at Hamadat and Syatin sections by nummulitic lime mudstone to wackestone, besides other less dominant microfacies as nummulitic floatstone with wackestone matrix, pelecypodal floatstone, mollusca and operculines floatstone. Continental slope facies is mostly represented by wackestone microfacies that intercalated with lime mudstone of tidal flat facies. Open marine facies is represented by foraminiferal lime mudstone and calcareous shale except at Malha section where it is missing.
The studied succession shows regressive trend where the open marine facies at base of succession grade upward into deep and then shallow subtidal facies at the top. The oyster limestone facies dominates the upper part indicating shallowing upward conditions.