44 Mr Nash on the Geology of Egypt. 



Valley of Cosseir. 



Between the Nile and the Red Sea are several ranges of hills, 

 forming, for the most part, one mountain-chain, which has a di- 

 rection nearly north and south, crossed by several transverse 

 valleys, of which the one best known is the Valley of Cosseir. 

 This valley, running nearly east and west for 1 20 miles, forms 

 a plain covered with a fine sand composed of quartz and lime- 

 stone, and having its surface strewed over with fragments of 

 quartz, jasper, agatej and common flints. It is bounded on 

 each side by the hills through which it passes, and which pre- 

 sent, in some places, very precipitous escarpments ; in others 

 steep slopes, the basis of which are masked by low hills of de- 

 bris. In this valley, three principal formations are seen ; the 

 limestone, the sandstone, and the primitive or plutonian rocks. 

 In its course it presents one natural spring of mineral water; and, 

 where the sandstone prevails, wells have been sunk from which a 

 brackish water is obtained. Its appearance fully justifies the ap- 

 pellation of the Dessert of Cosseir ; for, with the exception of two 

 or three stunted acacias, there is no trace of vegetable life. 



The town of Cosseir, on the western shore of the Red Sea, 

 in about 24J north latitude, is situated at the eastern entrance 

 of this valley. This town it built on an ancient coral reef, now 

 elevated a few feet above the level of the sea. Behind the town 

 is a still more ancient coral reef, raised in some places as much 

 as twenty feet, and containing numerous univalve shells in a 

 very soft and decomposing state. Upon this reef lies an argilla- 

 ceous marl containing large quantities of gypsum, and above 

 this a layer of rolled pebbles covered with angular fragments of 

 sandstone, quartz, jasper, felspar, and granite, derived from the 

 neighbouring hills. These marls and rolled pebbles mixed with 

 gravel, form low rounded hills which cover the whole plain from 

 immediately behind the town of Cosseir to the eastern debouche- 

 mcnts of the valley of the same name. 



On leaving Cossier, the traveller passes for the first hour among 

 those low gravel hills, which soon give place to more lofty ele- 

 vations of limestone and granite. At Ambagi there is in the 

 limestone a mineral spring, exceedingly bitter, so much so as to 

 be refused even by the camels. The granite now appears break- 

 ing through the limestone, which rests upon it in highly incli ne d 



