Impact of the subsurface structures on the groundwater occurrence in the southeastern part of Wadi el-Farigh, west Nile delta, Egypt

الملخص EN

The study area is bounded by the latitude of Khasm El-Kalb from the east and to the west of SUMID LINE from the west, and extends between km 56 and km 67 along Cairo-Alex.

Desert Highway.

The structural setting prevailing the concerned area plays an important role in the levels of the basaltic sheet, which consequently has a direct effect on the groundwater occurrence.

This basaltic sheet is overlain by the unconfined Lower Miocene aquifer (Moghra Formation) and is underlain by the confined Oligocene aquifer. The present study deals with the subsurface geological structures and their direct effect on the vertical and horizontal distribution of the water bearing formations.

To achieve the aim of this study, a geoelectrical study was carried out through the conducting of 36 Vertical Electrical Soundings (VES) with a maximum current electrode separation of 4000m of Schlumberger configuration. Also, the available data of 22 drilled wells was used in this study.

This study reveals the presence of 4 main geoelectrical layers.

These layers, from top downward are: dry layer “A”, an upper water bearing layer “B” which is represented by Moghra formation, Oligocene basaltic sheet “C” and the lower water bearing layer “D” of Oligocene sediments.

The area is affected by a number of NE–SW and NW-SE faults which are detected through the correlation of the basaltic sheet levels.

These faults have a great effect on the groundwater occurrence, as well as, on the connection and disconnection of Moghra and Oligocene aquifers in the investigated area.