The Western Desert
The Nile, winding its way in an S shape from south to north, divides
Egypt in two big desert areas: the Western (Libyan) Desert, which covers
680,000 km2
, i.e. more than 68 per cent of the total area of the country
(1,002,000 km2
), and the Eastern (Arabian) Desert, which covers an area of
220,000 km2
, i.e. more than one-fifth of it. As has been mentioned before, the
Western Desert consists mainly of Mesozoic and Tertiary nearly horizontal
layers of limestone and of sandstone (see Figure 4.1). Geological structures
and tectonic conditions caused the formation of vast plateaus and escarpments
which formed glacis of debris on their steep slopes when arid morphodynam-
ics prevailed for a longer period of time. On the plateaus we find hamadas,
deserts of debris which developed through the weathering of the upper layers
of sediment rocks. On the lower plains as well as in the basins, ergs with
mobile crescent-shaped barkhan dunes were formed. The largest area of ergs
is in the Great Sand Sea, which runs in a north-westerly–south-easterly direc-
tion over hundreds of miles in the western part of the Western Desert.
In the Western Desert there are three areas of potential economic use.