240 me. a. wade ox the [May 1911,. 



with sand. Neither does it seem probable that these beds could 

 have been formed as a result of the torrential rains which 

 sometimes occur in these hills. Such rains are very violent at 

 times, and the great volume of water resulting from them 

 produces astonishing effects in the gullies. The torrents, however, 

 rather tend to cut through and to destroy the mounds than to 

 create them, and the general effect of the rains which occurred 

 while I was in the desert seemed to be to slope off the cliff-like 

 terminations of the ' gravel '-mounds, and to distribute their 

 materials farther over the plains. Moreover, such action would 

 not easily explain the existence of the mounds which lie at some 

 distance from the main hills, such as those south of the Gulf of 

 Jemsa; nor will it account for their plateau or terrace-like characters. 

 Glacial action might possibly account for some of the principal 

 features ; but no signs of glacial action have ever been noted by 

 any of the travellers who have explored the hills of the Eastern 

 Desert. 



Some clue may be obtained from a consideration of what is- 

 now taking place along this coast. Three distinct raised beaches 

 are recognizable, both at Abu Sha'ar and on the coast near Jebel 

 Zeit 1 ; while a stud} 7 of the islands off the coast shows that four or 

 even more periods of marked elevation have occurred within com- 

 paratively recent times. One beach, at a height of over 80 feet, 

 corresponds very closely with the level at which the mounds 

 usually begin : this is well shown at Jebel Zeit. Again, in places, 

 the igneous fragments are cemented together by a calcareous cement 

 which contains marine fossils of Pleistocene age. 2 Occasionally*,, 

 beds of coarse limestone are associated with them ; while among 

 the angular fragments of the ' gravels,' broken shells of recent Eed- 

 Sea types may sometimes be found. Finally, we may note the 

 peculiar manner in which the plain runs right up to the base of 

 the [' gravel ; ] hills, ' against which it stops abruptly like a beach 

 against a cliff.' 3 



All the foregoing observations point to the conclusion that 

 these beds are talus-heaps, derived from the eastern slopes of the 

 Red-Sea Hills by the action of the sea-waves beating against their 

 cliffs and slopes. 



The rapid rise of this coast and the very insignificant action of 

 the tides in this part of the Red Sea are sufficient to explain the 

 absence of rounding in most localities, although this absence is not 

 invariable. Conditions favourable to the rounding of the pebbles 

 occurred in places, probably where strong currents were active. 

 The sharp turn in the coast at Jebel Zeit appears to have been 

 such a place, and beds of rounded pebbles here reach a height of 

 nearly 330 feet. 



1 T. Barron & W. F. Hume. Egypt, Geol. Surv. Sep. 1902, pp. 123-25. 



2 Ibid. p. 126. 3 Ibid. p. 70. 



