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towns stand upon this formation. It is suspected by some observers, 
on account of the obliteration or shallowing of anciently deep har- 
bours, that the process by which the fringe was raised above the 
level of the sea is still in operation, and Mr, Newbold is of opinion 
that the forces which effected the upheaval acted gently and gradually. 
He objects, however, to the inference that the isthmus of Suez has 
been recently raised, on account of the difference in the faune of the 
Mediterranean and the Red Sea. 
Among the post-pliocene formations, the author includes the ac- 
cumulations now forming around the Red Sea and in the Mediterra- 
nean on the shores of Sicily, Greece, Asia Minor, &c. On the west 
shores of the Red Sea he has noticed them five or six feet above 
high-water mark, overlying a raised coral beach. They sometimes 
enclose bones of the camel; and in the island of Rhodes Mr. New- 
bold observed in a similar formation fragments of ancient pottery. 
In the valley of the Nile, on the plain of Benihassan, myriads of 
Nummulites, washed from the overhanging limestone, are partially 
re-cemented by calcareous matter deposited from springs and form 
layers which alternate horizontally with others composed of clay, 
sand and gravel, the whole in some places attaining a thickness of 
morethan 30 feet. In the valley of Kossier, beds of gravel and other 
detritus are gradually becoming consolidated by a calcareous or fer- 
ruginous cement derived from percolating water; and in the cliffs 
skirting the Mediterranean, between Alexandria and Aboukir, Mr. 
Newbold observed a bed of bleached bones, derived from Roman and 
Greek cemeteries, with an intermixture of more modern human re- 
mains, overlaid by a layer of occasionally agglutinated sand or gravel, 
sometimes from three to four feet thick. 
7. Drift-—Under this head the author includes, Ist, the saline 
sands and gravel of the deserts, derived in great part, he believes, from 
the fossil-wood sandstone formation, but generally much influenced 
in each portion of the deserts by the character of the rocks in the im- 
mediate vicinity; and 2ndly, the gravel beds which cover the raised 
coral beach of Kossier and the limestone cliffs of the Red Sea near 
the Jaffatine group, also the detritus resting on the elevated platform 
of the Libyan desert near Dendera, the materials composing the 
whole of which consist. of far-transported plutonic and metamorphic 
pebbles, intermingled with others derived from adjacent formations. 
8. Volcanic Rocks,—After alluding to the supposed volcanic. 
cones or extinct craters in the desert between Cairo and Suez, and 
to others said to exist in the vicinity of Dakkeh, situated m the 
Nubian. desert 69 miles from Syene, Mr. Newbold proceeds to de- 
scribe the trap and porphyry dykes which in Upper Egypt penetrate 
all the rocks from the lower sandstone to the granite, and have been 
already noticed in the account of the formations through which they 
pass; the author, however, observes in addition, that the relative age 
of the trap is defined by the upper or fossil-wood sandstone being 
undisturbed, and by its sometimes containing pebbles of the trap. 
Granitic or syenitic rocks are of rare occurrence in Egypt, aps 
" peating only at the cataracts of Syene, and in the desert between the 
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