Abstract
In Egypt the strata of major hydeogeological interest are composed of a sandstone complex ranging from Cambrian to Upper Cretaceous in age. Known as the Nubian Sandstone, this complex has a thickness varying from less than 500 m to over 3000 m and rests directly on Precambrian basement. A number of major structural fault and fold axes traverse the region in a north-easterly direction. Basement features exercise a dominant control on the structural and sedimentological form of the sandstone complex. The Nubian sandstone underlies an extensive area of Egypt and probably constitutes a single hydrogeological system to the West of the Gulf of Suez. To the east on the Sinai peninsula, a second system may exist with some cnnection to the main western system in the north. The western system comprises a multi-layered artesian basin where huge groundwater storage reserves were accumulated during the pluvials of the Quaternary. The carbonate rocks overlying the Nubian sandstone display karst features locally and are recharged by upwards leakage from the underlying major aquifer. (Titus-FRC)