48 Visit to Mount Sinai. [No. S3, 



ostreoe, echini, madripores, pecteus. Rock-salt and Gypsum occur 

 in layers. 



The limestone beds of Jebel Pharoun, Jebel Hummam and other 

 ranges on the eastern coast, appear to be spurs and outliers from 

 Et Tih. 



The central region around Mount Sinai presents a magnificent 

 outburst of granitic and porphyritic rocks which have uplifted and 

 thrown into confusion a zone of hypogene rocks, principally horn- 

 blendeschist and gneiss, all penetrated by great dykes of basaltic 

 greenstone, which present a singular feature in this extraordinary 

 tract, passing through and over high bare mountains of red granite, 

 in dykes and walls, and adding much by their black rugged exterior 

 to the desolation which prevails. 



The greatest elevation which the granite attains is within a short 

 radius from Mount Sinai — itself a granite mass 7,412 feet above the 

 sea. Mount Catherine 2 miles to the S. W. is 8,063 French feet ; 

 Jebel Serbal 6,342 French feet; Om Shomar, about 7 miles S. by 

 W. from Mount Sinai, is however said to be the highest peak in the 

 Peninsula. 



The heights of the southern prolongation of the central region 

 towards Has Mahomed, put down in the maps under the general 

 term of Jebel Et Turfa, have not been ascertained. The nearest 

 approach of the granite to the western coast is near its N. W. angle 

 in about 29^ 4^ at Wadi Dhafery. At Tor it is about 5 miles dis- 

 tant. It spreads out, breaking up the hornblendeschist, to the 

 eastern coast, where it forms a range from 800 feet to 2,000 feet 

 above the sea. Emerging on the north in about latitude 29" from 

 the sandy plain of Debbater Ramleh at the base of the plateau of Et 

 Tih it disappears to the S. under the tertiary fossiliferous limestone 

 of Ras Mahomed. 



Sandstone for- A broken frame-work of sandstone is seen resting on 

 mation. borders of the granitic and hypogene areas, and 



sometimes entangled in them, the limits of which it is difficult to de- 

 fine. On the north it appears to be bounded by the limestone of Et 

 Tih and is seen near the coast of the Hed Sea in the vicinity of Ras 

 Zulima, a little south of the limestone of Jebel Pharoun, and forms 

 the ranges of Jebel Mookattil, En Nasb, Serabut, al Kadim, and the 

 mountain of the Bell, " En NaMs" S. of which it disappears under 

 the tertiary limestone of Jebel Hummam and El Kaa near Tor. 



