50 Hugh J. L. Beadnell — Flowing Wells, Kharga Oasis. 



district of Tibesti, while on the east it stretches to the outlying oases 

 of Fezzan and Tripoli. Its area is approximately equivalent to that 

 of the British Isles. 



Except for a narrow belt fringing the Mediterranean the region 

 is practically rainless, so that unlike the more elevated deserts on 

 the other side of the Nile, where the rains are of sufficiently frequent 

 occurrence to maintain a water-supply in the isolated water-holes 

 and valley springs, and to allow of the growth of a fairly permanent 

 though scanty herbage in the more favoured areas, the greater 

 portion of the Libyan desert is quite devoid of vegetation, and is 

 uninhabited even by nomad tribes. The extreme barrenness of the 

 region as a whole, however, is in great measure counterbalanced by 

 a number of isolated highly fertile oases, in which there is a permanent 

 resident population. 



The chief groups of oases are the Siwan on the north, that of Kufra 

 on the west, and the Egyptian, including the four large oases of 

 Baharia, Earafra, Dakla, and Kharga, on the east. 



The Egyptian oases occupy extensive depressions cut down nearly 

 to sea-level through the generally horizontal rocks forming the Libyan, 

 desert plateaux. These depressions owe their origin in great measure 

 to the differential effect of subaerial denudation acting on rock masses 

 of varying hardness and composition. Variation in the original 

 conditions of deposition has resulted in a preponderant development 

 in some areas of soft argillaceous beds, and subsequent folding has 

 raised these beds in some districts and depressed them in others. 

 Wherever during the general denudation of the country these soft 

 deposits have become exposed, weathering has proceeded at an 

 increased rate and gradually produced deep and broad depressions 

 separated by elevated plateaux. 



Geological Sequence in Northern Klmrga. 

 The geological succession (excluding Pleistocene and Recent 

 superficial deposits) in the northern part of the oasis of Kharga, 

 determined by actual measurement of the different stages exposed on 

 the floor and in the cliffs of the depression, and from numerous bores 

 put down within the last two years, is as follows : — 



Average thickness 



T -ri ( Lower Libyan. 



Lower Eocene | p^^^^^^ ^^^^ 



TJppEK Cketaceous 



Danian 



Campanian 

 ^ (Xubian Series) ' 



630 

 See Map, Fie;. 1, p. 51. The numbers 1-10 correspond with section 

 (Fig-. 2) given on p. 55. 



For the Eocene limestone, which everywhere caps the plateau 

 between the oasis and the Nile Yalley and also the northern bounding 



