Origin of the Qattara Depression, Egypt

Urban geology of African megacities

“…Its slopes descend to pediments graded southward to an axial valley. According to Albritton et al (1990), the cavernous sub-surficial limestone components which together with numerous smaller sinkholes constitute this massive Depression, attest to past karstic activity. The Qattara Depression contains a number of oil concessions and several operating fields.…”

“…The Depression is excavated in Tertiary sedimentary rocks having a regional dip of a few degrees towards the Mediterranean Sea [ Albritton et al, 1990]. The precipitous northern wall is the scarp slope of a cuesta capped by carbonate rocks of middle Miocene age.…”

Fluvial Transport Model from Spatial Distribution Analysis of Libyan Desert Glass Mass on the Great Sand Sea (Southwest Egypt): Clues to Primary Glass Distribution

“…The depressions were formed by the running water of the Gilf River that reached the shore, carving the depressions by dissolution of carbonates that were underlying the more resistant Miocene limestone dipping-northward-layers. This latter hypothesis on the formation of the northern depressions of the Western Desert of Egypt was supported by the discovery and study of paleorivers detected by radar, and it was formulated in conjunction with the fact that a humid climate during long time periods favored the recharge of the Gilf River from the highlands of the Gilf Kebir Plateau [4,35]. Brown ellipse: the smallest distribution zone [6]; red line: the largest distribution zone [9]; orange line: the common western limit of LDG deposition [8].…”

Erosion around a large-scale topographic high in a semi-arid sedimentary basin: Interactions between fluvial erosion, aeolian erosion and aeolian transport

“…Pans form relatively flat, closed depressions that may cover thousands of square kilometers, such as the Etosha pan in Namibia (Hipondoka, 2005;Miller et al, 2010). Those that do not have a karstic origin (Albritton et al, 1990) usually form upon sedimentary rocks in wide flat areas mostly through a combination of wind deflation, salt weathering and, during wetter periods, lacustrine processes (waves) (Goudie, 1991;Wormald et al, 2003). In the absence of erosion-resistant obstacles, pans have a rounded to oval shape due to the relatively homogeneous mechanical resistance to erosion of the substratum (Goudie, 1991;Goudie and Wells, 1995).…”