Dr. John Ball—The Nile Valley and Gulf of Suez. 73 
generally westwards. This is confirmed by the gradual rise eastwards 
of levels of the springs, and of the junction of Cretaceous and Kocene 
beds as one skirts the north scarp of Wadi Araba. 
My observations of the other side of the gulf were sally telescopic. 
But even casual scrutiny of the hills of the opposite shore (Gebel 
Hammam) showed the beds there to be dipping markedly away 
from the gulf. Telescopic observations of geological structure are 
always to be received with caution, but in this case my observations 
are confirmed by those of my late lamented colleague, Mr. Barron, 
who, from an actual examination of the place, records! that the strata 
of Gebel Hammam dip 10° eastwards. 
So far as general structure goes, therefore, the beds on the two sides 
of the Gulf of Suez dip away from the gulf, showing the gulf to be an 
anticline. 
The seaward faces of the North Galala plateau exhibit in many 
places a step-like form due to the faulting down of the strata in the 
same manner as those of the Wadi Araba, and at several points the 
faults are cut through by small lateral valleys which allow of their 
easy examination. The impression produced in all these cases is that 
of land-slipping at the face of the scarp, and not that of the letting- 
down of a tract extending across the gulf. One of the best exposures 
is the north face of a hill-mass in latitude 29° 34’, close to the north- 
east corner of the North Galala plateau. I climbed this hill, on which 
I had a trigonometrical station 1295 feet above sea-level, and found 
its lower part to be composed of yellow-brown and white lmestone 
and marls (Cretaceous), while its upper part was mainly hard lime- 
stone, which I believe to be chiefly Eocene with a thin covering of 
Miocene. ‘The whole of the beds dipped strongly (18° to 25°) towards 
the main scarp. Standing on the hill-top, one can see, high up on the 
main scarp to the west, the same Cretaceous limestones and marls 
which form the foot of the hill, while the hard Hocene limestones cap 
them at a height of over 2000 feet. Proceeding a short way along 
the coast north of this hill, one can obtain a very clear view of the 
faulting. The fault or slip-plane is inclined at only 22° to the 
horizontal, of course downward from the scarp, and the faulted-down 
Eocene limestones of the hill abut against the purple and brown 
sandstones and clays (possibly in part Carboniferous) which form the 
lower part of the main scarp. ‘he flat angle of the fault-plane is 
significant, and points far more to a great landslip at the face of the 
scarp than to organic faulting of the earth’s crust. The high dip 
of the slipped-down beds towards the scarp is also entirely against 
trough-faulting of the gulf; for if the beds ever extended far seawards 
with anything like the same dip, they would have attained a height 
much greater than that of the main plateau. ‘The conclusion seems 
justified, therefore, that the faulting along the shore of the gulf is 
purely land-slipping, and has nothing to do with the main tectonics 
of the gulf. In other words, the Gulf of Suez, like the Wadi Araba, 
is not a trough-fault, but an eroded anticline. 
' Topography and Geology of the Peninsula of Sinai (Western Portion), Cairo, 
1907, p. 30 
