INVISTIGATION OF THE SUBSURFECE GEOLOGIC SCTION AND GROUNDWATER POTENTIALITY IN WADI AL-ASSUITY AREA, EASTERN DESERT, EGYPT, USING SEISMIC REFRACTION METHOD

The present study represents an application of the seismic refraction techniques to investigate the upper part of the subsurface geologic section and groundwater potentiality in the entrance of Wadi Al-Assuity, Eastern Desert, Egypt. A complex set of observed refracted traveltimes along the seismic profiles is used. 2D homogeneous function method was applied to the obtained data of the traveltime curves of the first arrivals. The homogeneous function automatically inverts first arrival refractions to derive a 2D velocity distribution, which involves seismic boundaries. Such sections allow viewing the complex layered structure and delineating its boundaries and faults. The interpreted geoseismic layers were traced, according to their own gradients and velocity ranges. Four geoseismic layers with different ranges of velocities and velocity gradients were detected. Possible water-bearing layer is expected at depths ranging between 20 and 75 m at the northern and southern parts respectively. The thickness of the aquifer, which is probably feeding from the River Nile, ranges from 20 to more than 50 m. This aquifer has velocity ranges from 2000 to 2600 m/s with low velocity gradient. Moreover, a high degree of faulting is suggested from seismic interpretation, where significant lateral velocity variations exist along all the measured profiles. Furthermore, small isolated anomalies with diameters of about 10-20 m may be related to lenses of the saturated sandstones.