HUDLESTON: GEOLOGY OF PALESTINE. 
191 
condition, and Mr. Davidson had no difficulty in determining it. There 
are other indications that portions of the Nubian Sandstone of the 
Sinai Peninsula are of the Carboniferous age. There is for instance, 
in the Museum of the Geological Society, a cast of vegetable 
impression, marked Lepidodendron Mosaicum. Formerly a certain 
amount of suspicion attached to this fossil, and doubts were thrown 
upon its being an authentic specimen from the Sinai Desert. It was, 
I believe, brought to the late Sir Roderick Murchison, and probably 
received its name from the late Mr. Salter. Since the discoveries of 
undoubted carboniferous Brachiopoda there seems no reason to doubt 
the so-called L. Mosaicum is a genuine Sinai fossil. 
At the base of the Tih escarpment is a fossiliferous deposit 
containing Cenomanian urchins, &c. There is a strong tendency on 
the part of both M. Lartet and Dr. Fraas to regard the whole or 
nearly the whole of the Nubian Sandstone as of Cenomanian age. 
Dr. Fraas, in his last publication is very decided on this point, and if 
his statements are to be relied upon, the Carboniferous exposure in 
\ the Wady Nasb must present a very exceptional phase. 
Let me say a word about the turquoise mines. These occur at 
Serabit-el-Khadim and other places, in the Wady Nasb district, 
where they have been worked at intervals of time for ages. This 
was a great mining country for the ancient Egyptians. The tur- 
quoise occurs for the most part in ochreous balls that are situated in 
certain horizons of the Nubian Sandstone. The best stones are in 
the solid sandstone, a short distance from the joints. Here again, Mr. 
Bauerman is at variance with Dr. Fraas, who says, that the turquoise 
occur in gneiss. The mineral wealth of the sandstone region is very 
considerable, both iron and copper occuring in abundance. The 
Arabs were very recently working for turquoise, and have destroyed 
many inscriptions in these sandstones. Burton, a few years ago, 
made an expedition into the land of Midian, wffiere the sandstone 
prevails, and brought away great quantities of minerals. 
The last thing to consider is the effect which the Nubian Sand- 
stone has on the scenery of the districts where it prevails. Professor 
Palmer gives us some capital descriptions.* 
* Yol. cit., p. 17. 
