1847.] 



Visit to Mount Sinai. 



55 



The last two bore southerly of the other peaks. Mount Sinai was not 

 visible hence. 



The plain is covered with sand generally of a coarse quartzose 

 nature, often strev/n with a gravel composed of fragments of the 

 granitic and hypogene rocks, both angular and rounded, from the size 

 of a pea to that of an orange ; the pebbles are principally of reddish 

 granite, porphyritic and close-grained hornblende-schist, basaltic 

 -greenstone, compact felspar coloured green v/ith actynolite — actyno- 

 lite with quartz and felspar in drusy crystals, and porphyry of vari- 

 ous descriptions including melaphyre. The most prevalent variety 

 is like that of Egypt, being composed of a brownish felspathic paste 

 imbedding felspar crystals of a light reddish brown, white and of a 

 pink hue ; also a black augitic paste imbedding crystals of red, white, 

 or pale green felspar. 



„ , „ , Wadi Hebron is a transverse fissure in the western 



Wadi Hebron. . ^r... - ^ ^ cx 



ranges of the pemnsula of Smai, which here run S. 



by E. towards the apex, at Ras Mahomed. This pass is often from 



300 to 400 yards broad, but sometimes contracts to 20. The course 



at the entrance is E. N. E.but afterwards winds about. Its sides are 



composed of bare rocks, often rising almost perpendicularly from 200 



to 700 feet high. The rocks are of a granitoidal gneiss in nearly 



vertical strata penetrated by granites, dykes of basaltic greenstone, 



and porphyry. 



Opposite the mouth of the pass, the torrent which during the rains 

 issues from it dov/n to El Wadi, has worn its way through deep beds 

 of gravel which are seen to extend along the seaward base of the 

 mountains to the right and left of the mouth of the pass. 



They are piled up to the height of about 40 feet near the moun- 

 tains and gradually slope into the general level of the plain. 



These beds of gravel could not have been altogether accumulated 

 by the present torrents of the wadis which however during the rains 

 rush down with force enough to tear up trees, and cover a consider- 

 able space of ground with debris, but their utmost limit does not 

 extend to those of these gravel beds, which appear to me to be more 

 like the remains of an ancient coast-line in which the mouths of the 

 wadis formed indentations or bays. I could not trace any decided 

 glacial furrows on the sides of the rocks. In localities where furrows 

 did exist they were always more or less conformable to the relative 

 hardness or softness of the rock and its veins. 



