D)'. W. F. Hume— Rift Valleys of Eastern Sinai. 199 



two sides being frequently of diffei'ent geological structure, this 

 contrast having often a very marked effect upon the scenery', as, 

 for instance, where the rift separates the granite range of Ashara 

 from the felsitic hills of Feraui, the former rising in sharply peaked 

 red-coloured crests scored by wild gorges, while the latter are of 

 dark-green colour, and possess less rugged outlines. 



Still more noteworthy is the presence of sandstones in the valley 

 itself, having all the typical characters of the Nubian Sandstone, 

 yet situated 25 kilometres south of the main mass of that formation ; 

 similarly, at the head of Um Raiyig, a ridge of Cenomanian lime- 

 stone, with sandstone at its base, block the valley, being enclosed 

 between two walls composed of Nubian Sandstone resting on granite. 

 Still further to the north the reverse is met with, a granite ridge 

 running north and south, rising steeply through the surrounding 

 sedimentaries. The examination of the relations of the beds over 

 the area shows that the actual displacement of strata in the 

 production of the rift varies from 200 to 600 metres (2,000 feet). 



The Eaib Melhadge rift is in some respects even more striking, 

 the granite range extending far further to the north on its eastern 

 than on its western border, which for some distance is formed by 

 lower country, geologically a complex of granite, sandstone, and 

 Cenomanian limestone. As a result, in the upper part of Wadi 

 Eaib, Cretaceous limestone forms low ridges dipping steeply eastward 

 at the foot of a granite range, which rises immediately above them 

 to a height of over 300 metres. Descending Wadi Eaib the 

 conditions become simpler, the Nubian Sandstone on the west giving 

 way to granite cliffs, and the valley becoming a bi'oad highway 

 bounded on both sides by precipitous height. Yet scattered all 

 along its course are low hills of white Nubian Sandstone, and in one 

 place Cenomanian limestone, so that the surprising result is realized, 

 that Cretaceous fossils were collected from a limestone on both sides of 

 which tower granite cliff's to a height of over 500 metres (themselves 

 in places capped by Nubian Sandstone), the extent of dislocation being 

 here at least 700 metres. Further to the south, the same rift gives 

 rise to a Coastal Watershed Eange of some importance. 



The other valleys are considered to be rifts on account of their 

 parallelism to those already described, while they also must have 

 been produced by the same series of movements which gave rise to 

 the Gulf of Akaba. 



Correlation of Eastern Sinai Rifts with those of neighbouring 

 districts. — In returning from Eastern Sinai the writer was struck 

 by the resemblance of the western valleys to those already 

 described, the clefts, viz. Nagb Hawa and El Watiyeh, which 

 break through the granite hills, barring the Sinai convent region 

 to the north, being the continuations of remarkable lines of depression 

 which can be traced far to the north-west. One of these, which 

 includes the Convent Valley and runs to Wadi Suwig, is especially 

 straight and well defined, but, in common with the other western 

 valleys, is parallel, not to the Gulf of Akaba, but to the Gulf 

 of Suez. 



