100 W. M. Fontaine— Geology of the Blue Ridge. 
The Blue Ridge is here again a single chain, composed en- 
tirely of crystalline rock. There are no considerable hills 
lying to the east of the main ridge. This latter rises imme- 
diately from the valley mentioned, with a rounded, gently 
swelling slope, bare of surface-earth, but covered profusely 
with immense boulders derived from the mass composing the 
Peaks proper. 
After attaining the summit of the slope, we find ourselves on 
a level with a valley lying to the west. This lies along the 
foot of a chain of mountains situated farther west, which rivals 
the Blue Ridge in height, and is composed of Silurian strata. 
The summit of the slope is about 1500 feet above the valley 
on the east. 
On each side of this point rises abruptly a mountain 1600 
feet above the pass. That on the right, composed of the same 
rock with the one on the left, is not an isolated peak, but it is 
the end of a great mass of mountains which extend northeast 
as far as the eye can reach, and even surpass in height this 
ak. The elevation on the left, which, with the one just men- 
tioned, forms the Peaks of Otter, is an isolated eminence. It 
stands up abruptly from the coarse syenitic mass forming its 
base, like a huge chimney, showing by its bare, abrupt faces, 
that it is composed of different material from the softly 
rounded, well-worn base on which it stands. In ascending 1t 
nd the coarse syenite accompanying us to within 600 feet 
of the top of the crag, which forms the highest point. This 
would seem to indicate that in the pass at least 1000 feet of 
the older coarse rock has been scooped out, for the two peaks 
facing each other present similar features. To the southwest, 
the great elevation seen at the Peaks is soon lost. There the 
erystalline mass rapidly sinks down into several low finger-like 
spurs, and farther on no elevation which can be called a moun- 
tain occurs. e Virginia and Tennessee railroad passes the 
Blue Ridge at Buford’s Gap without tunnelling, and by mode- 
rate grades. In this region, as Rogers has stated, the Silurian 
range to the west is called the Blue Ridge. 
The following then is the structure of the mountain at the 
Peaks. The main mountain rises in the form of a broad, soft] 4h: 
rounded ridge, composed of coarse syenites, like those descri 
at the east base, and like the a on James River west of 
Lynchburg. From this, as a base, rises abruptly on the west 
side near the east limit of the Silurian strata, a broad ledge of 
a totally different rock, which will be presently described. To 
this latter mass, which is about 900 feet wide, the mountains 
owe their additional height of 1600 feet. 
any peculiar features of erosion and the transport of mat- 
ter occur, to adequately describe which too much space would 
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