The Western Desert, Egypt includes the major groundwater aquifer in the country. It is apart from the
Major Sahara Nubian Aquifer which is present in Sudan, Chad, Egypt and Libya. Thickness of this aquifer
is changed laterally from south to north and also from west to east. The changes may structurally or litheologicalley
control. The present study is focused on using of Bouguer gravity anomaly mapped at a scale
of 1:500,000 and the lithological logs of about 120 deep wells used to determine the thickness of the sedimentary
sequence containing the main Nubian sandstone water aquifer in important area of Egypt. The
area is located in the southern part of the Western Desert bounded by the latitudes 22000–26300N, and
longitudes 28300–33000E. The predominant structures affecting the basement rocks and the sedimentary
cover were traced and analyzed. The gravity stripping approach was applied to eliminate the gravity
effects caused by sedimentary sequence and to separate density anomalies within the sedimentary fill
from the influence of rocks at deeper levels in the crystalline crust.
The study indicated that the surface of the basement rocks is highly rugged and mostly controlled by
structures which have a direct effect on thickness variation of the sedimentary cover all over the area.
Regionally the area is characterized by two major intracratonic basins (the Dahkla Basin and the Nile valley
Basin) separated by a NE–SW trending swell of the Kharga uplift and bounded at the south by the
Oweinat–Bir Safsaf–Aswan uplift. These major tectonic units are controlled by fault structures trending
in N–S, E–W, NE–SW, NW–SE, which cut the basement rocks and extend upward in the sedimentary
cover. The maximum thickness of sandstone formations is recorded at west Oweinat, west Kurkur, southwest
of Aswan, Gramashin, Dakhla oasis and some localities west of Sohag and Qena towns. At these
localities the thickness ranges between 600 and 900 m. As this formation is the main water aquifer in
the study area, therefore these localities are characterized by the presence of big amount of ground water.
Accordingly, these areas must take the priority in the sustainable development programs of southern
Egypt