18 ANNUAL 
have been so fully described, especially by the late Professor 
Palmer, Sir Charles Wilson, Oscar Fraas, De la Borde, 
Dean Stanley, and others, that little need be added here. 
From the summit of Mount Sinai Colonel Kitchener was able 
to take the bearings of numerous points with the theodolite, 
and thus to connect the triangulation of the Peninsula 
with that of Southern Palestine along the Arabah Valley. The 
magnificent survey of the Sinaitic Peninsula by the officers 
of the Ordnance Survey had left little to be desired. 
Where it terminated towards the Gulf of Akabah it was taken 
up by the members of our Expedition, and the result is an 
elaborate map of the Valley of the Arabah, from the head of 
the Gulf of Akabah to the shores of the Dead Sea. And in 
a reduced copy of this map (on a scale of six inches to the 
English mile) I have inserted the geological details with as 
much accuracy as our reconnaissance would permit.* 
The rocks of the Sinaitic mountains, including Jebel 
Serbal, are formed chiefly of granite, gneiss, various schists, 
invaded by porphyry and other igneous rocks. It is probable 
that these represent the oldest formation of the globe, known 
to geologists as ‘‘ Archean.’ Traced westward beyond the 
shores of the Gulf of Suez, they form much of the mountainous 
tract between the Red Sea and the Valley of the Nile, where 
they reappear, rising from beneath the Nubian sandstone at 
Assouan. 
In the Sinaitic Peninsula the crystalline rocks are overlain 
in certain directions by Carboniferous beds, originally dis- 
covered by Mr. Bauerman in the Wady Nasb, and visited by 
the members of the Expedition. These consist of red sand- 
stone and conglomerate, overlain by limestone with numerous 
shells, crinoids, and corals, identical with, or allied to, those 
of the Carboniferous beds of Europe and the British Isles. 
Numerous specimens of these fossils were collected and 
brought home for determination, and have served to place 
beyond doubt the geological age of the strata in which they 
occur. 
Throughout the Sinaitic Peninsula, evidences of the former 
existence of lakes and chains of lakes were not infrequent in 
the occurrence of deposits of marl, beds of gravel and: sand 
forming horizontal strata over some of the plains and valleys. 
It was also clear that at a former period the now water- 
less valleys had been occupied by large, and probably 
* The preparation of this map was undertaken by Mr. Armstrong 
(formerly Sergeant-Major, R.E.), of the Ordnance Survey of Palestine. 
+ The determinations were made by Prof. Sollas. of Dublin University, 
and are given in the Memoir, p. 48. 
