1M7.] 



Visit to Mount Sinai. 



69 



Pegmatitic veins, veins of felspar coloured green by actynolite, 

 veins of quartz and rock crystal in hexagonal pyramidal crystals, 

 both white, roseate and smoky, prevail in the granite particularly 

 in the porphyritic varieties. The crystals are collected by the Jebeli 

 or convent Arabs and sold as curiosities. 



Large dykes of basaltic greenstone can be traced for miles over 

 the granitic rocks. Veins of compact greenish felspar and eurite 

 ■are not uncommon in the granite, near these basaltic dykes. 



The rock composing Jebel Meneggia is principally of a chloritic 

 hornblende and a white felspar, spotted green with hornblende. 

 Some varieties would pass for diallage, in hand specimens, though 

 the rock has an obscurely stratified structure. Its weathered exterior 

 has a dark rusty colour. 



The dykes of basaltic greenstone rarely overlap the granite and 

 hypogene schist they penetrate, but seem to have existed in a soli- 

 xJified state in them, at the time they were broken up. 



Faults of considerable extent may be thus traced even in the 

 -granite itself. 



The following diagrams are taken from detached porphyritic 

 granite rocks of Wadi Abu Tok to the N. W. of Mount Sinai, which 

 have been greatly invaded by basaltic dykes. 



The general direction or stratification of the hypogene schists, 

 forming the lower ranges around Mount Sinai is nearly N. and S. 

 but great disorder is visible both in dip and stratification. The 

 «chists are often seen on their edges. 



Around Mount Sinai with the exception of the gardens, there is 

 not so much verdure as in Wadi Hebron and Feiran where the 

 waters of the springs linger in the bottom of the vallies. In Wadi 

 Hebron, the tamarisk [turfa or manna] which is usually little 

 higher than a bush sometimes rises to the dimensions of a tree nearly 

 30 feet|high; we sa^Y no manna either on or in the ground under 



