328 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 
during the greater part of the year; and Mediterranean. 
the Nile may be said to be the only 
river of Egypt ; one remarkable feature 
of this mighty stream, which from the 
earliest dawn of history, by the unfailing 
periodical floods of fertility it has poured 
upon Egypt, has exerted a powerful 
influence on the civilization of nations, 
being, that during the last 1350 miles 
of its course, in all 2600 miles, it rolls 
onward a broad, majestic stream, with- 
out receiving what may be termed a 
single tributary. 
I shall now describe the rocks, com- 
mencing with the hypogene or meta- 
morphic strata, and thence to the more 
recent deposits in their order of super- 
position, from the first cataracts and the 
anticlinal line in the Thebaid desert, 
which may be termed the great water- 
shed of Egypt, to the Mediterranean 
(see figs. 1, 2). 
Extent, Position, and Lithological 
Character.—Hypogene rocks (g) consti- 
tute but a small portion of the surface of 
Egypt. lobserved them between the Red 
Sea and the Nile only in the latitude of 
Kossier (26° 8’ N.), resting in highly 
inclined and curved strata on the granite, 
(figs. 2,7) forming a zone of about thirty 
miles in breadth east and west, running 
probably in a south by east direction, ap- 
pearing at Gebel Zubara, lat. 24° 30'N.* 
In a southerly direction they have been 
traced resting on the granite of the cata- 
racts. In the southern part of Central, 
and in Lower Egypt they disappear alto- 
gether. Gmueiss is usually found lowest 
in the group with micaceous, talcose, 
and hornblendic schists, clay-slate and 
quartzite, superimposed in conformable 
stratification. All these rocks, within 
the limits of the zone alluded to, are 
associated with dykes of basaltic green- 
stone, porphyry and serpentine. Thin 
veins of marble occur in the gneiss. 
Near Ambagi, west of Kossier, the 
greenstone rocks are of a massive cha- 
Fig. 1. 
m the 1st Cataracts to the Mediterranean. 
Longitudinal section of Egypt fro 
Syene. 
per sand and gritstone with silicified wood. 
Upper nummulitic limestone. 
ower marine limestone. 
Sandstone—inferior. 
Alluvium of the delta. 
Granite. 
Up 
S ae an 
d. L 
g. Hypogene schists. 
é. 
f. 
a 
b 
c 
1000 feet. 
800 
600 
490 
210 
10) 
Seale of height in feet, 
200 
Scale of length in miles. | 
100 
10 20 30 40 50 
* M. Caillaud found copper and lead ore near the emerald mines of Zubara, | 
and also a sulphur-mine in Gebel Kebrit, but in what formation is not certain. _ 
