Structural depocenters control the Nubian sandstone aquifer, Southwestern Desert, Egypt: inferences from aeromagnetic data

Abstract

For the purpose of land use and developmental planning in southern Egypt, the region located northwest of Toshka area was selected for aeromagnetic investigation to define the basement structures that affect the Nubian Sandstone Aquifer. Herein, the total intensity aeromagnetic data are analyzed in detail using reduction to the pole (RTP), Butterworth filter, balanced horizontal gradient, and Euler deconvolution. Parallel faults oriented mainly in the NNE, NW, EW, and NS directions, dividing the area into parallel blocks of variable depth and width, are inferred from magnetic maps. Some of these blocks represent elongated depocenters with thick sediments that are suitable for groundwater accumulation. Assuming that the regional groundwater movement from the southwestern and southern areas of Sudan, Libya, and Chad recharges the Nubian groundwater aquifer in the Western Desert, these depocenters and bounded faults are considered to be good conduits for the groundwater. Therefore, the pattern and distribution of these depocenters could control the movement of groundwater in the study area. An elongated high-magnetic anomaly in the east indicates possible basement uplift, which could be correlated with the Kharga Uplift. This uplift separates the study area in the West from the Nile Valley in the East; therefore, seepage from the Nile into the permeable Nubian Sandstone Aquifer in this area is not preferable.