The middle Miocene-Pliocene sedimentary sequence cropping out in the area between Wadi Queih and Wadi Um Aish (South Safaga) is subdivided into five units: 1- Um Mahara Fm., 2- Abu Dabbab Formation, 3- Um Gheig Fm., 4- Marsa Alam Fm., and 5- Shagra Fm.
Develoment of these sediments clearly reflects four major stages of tectono-sedimentary evolution.
In the first stage (Middle Miocene) submarine talus and grabenal facies, followed upwards by restricted platform and talus facies were laid down. The second stage (Upper Miocene ?) wad dominated by restricted environments and resulted in the accumulation of mixed evaporite-carbonate facies. In the third stage (Upper Miocene?) continental fine siliciclastics were deposited. The fourth stage (Pliocene) was dominated by open marine environments depositing mixed siliciclastics-carbonates as well as dominantly carbonate facies.
Facies changes and styles of deposition displayed by these units are largely controlled by three phases of tectonic events. These include the easterly trening faulting which was responsible for the formation of Middle Miocene structural highs and depressions, the Upper Miocene? NW trending synsedimentary downfaulting (Sealed faults) and Pliocene E and NE trending shear fractures.