THE ROLE OF SUBSURFACE TECTONIC FAULTS IN SHIFTING THE COURSE OF THE NILE VALLEY BETWEEN EL-MINYA AND BENI SUIEF AREA, EGYPT, USING POTENTIAL DATA

The faulting picture at different levels might represent the geotectonic behavior affecting the earth's crust in a manner that the characteristic features of a given set of anomalies are related to certain function of the total affecting stress. In the present study, the Bouguer gravity and the reduced to the pole (R.T.P.) magnetic maps are analyzed using second vertical derivative method for clearing the shallow local structures. The depth to the regional and residual components are determined using power spectrum analysis technique and 2.5-D modeling program. Magnetic anomalies are analyzed into regional and residual components using Geosoft program. Both Bouguer gravity and R.T.P. magnetic maps are structurally analyzed for revealing subsurface faults. The structural features are mainly
faults having E-W (Tethyan trend), N-S (East African Rift Trend), ENE-WSW (Syrian Arc Trend), NW-SE (Gulf of Suez)
and NNE-SSW (Gulf of Aqaba trend) are prevailed. 2.5-D modeling technique was applied along one selected profile
on the Bouguer map. Finally, the interpreted structural map of the studied area is intensively analyzed showing
different subsurface elements affecting the studied area. Three inflection points along the main course trend of the Nile
Valley are recorded; the first lies at south of Samalut (changed from NW to nearly NE to Beni Mazar), the second lies
at Beni Mazar where the trend changes to nearly N-S direction (to Maghagha), and the third point started at Maghagha
and El-Fashn where the Nile changes its course toward the east with NNE trend (at Beni Suief).
Six major shear zones of strike-slip faults and about seventeen deep faults were revealed. These shear zones are responsible for the erupted basaltic rocks west of Beni Mazar. The spring located at west of El-Fashn and Ain El-Rayan El-Baharyia, Ain El-Rayan El-Wastanya and Ain El-Rayan El-Qeibliya. The main course of the Nile River seems to be affected by three major deep faults, one of them lies to the east, the second is present at the western side while the third fault occupies the central part of the Nile Basin. The surrounding uplifted igneous and hard sedimentary rocks play also an effective role in detection Nile River course. This proves that the main course of the Nile River is strongly controlled by subsurface tectonic faults parallel to it.