46 Mr Nash on the Geology of Egypt. 



the rocks of igneous origin, consisting of trap, gra- 

 nite, serpentine, and mica-slate ; the latter rock rises 

 to a great height at the pass of Abou Zeyran. 



There is also a breccia of serpentine and granite, 

 and a very beautiful puddingstone of serpentine and 

 porphyry. After passing these gneiss rocks, the 

 sandstone again makes its appearance, and extends 

 almost to the valley of the Nile, where it is again met 

 by the limestone formation, which, on the western 

 bank of the river, rises to a considerable height. 



In the remarks upon this valley, three considera- 

 tions present themselves as worthy of attention. 1. 

 That the igneous eruptions in this country have been 

 active since the formation of the limestone and sand- 

 stone deposits, which have been broken through by 

 the trap-rocks. 2. That the coast of the Red Sea 

 has undergone a very recent elevation, and is pro- 

 bably still undergoing a similar change. 3. That the 

 valley of Cosseir has, since the elevation of the lime- 

 stone, been traversed by some very powerful torrent 

 of water. With regard to the elevation of the coast 

 of the Red Sea, that this is recent, there is abundant 

 proof, both at Cosseir and at Jidda, on the eastern 

 coast of the Red Sea, where the low hills around 

 the latter town contain numerous Echinida, Asterias, 

 and marine shells similar to existing species, and also 

 from the circumstance, that the ancient canal which 

 led from Suez to the now marshy lakes to the north- 

 ward, the continuation of which to the west, to- 

 wards Cairo, is now called the Wadi Tomlat, has 

 been obliterated by this very means ; the elevation 

 of the land immediately around Suez being necessa- 

 rily subsequent to the formation of this canal which 

 was once navigable to Suez. 



The only point which remains for consideration, 

 is the age and character of the sandstone and lime- 

 stone formations of Egypt relatively to those of Eu- 

 rope. 



The sandstone formation of Egypt is, in its general \ 



I! 



</ A 



riu 



