108 
Leaving the South Mountains, they 
are seen to run S. and bend to the 
N. W- The formation is the Flinty 
Shale, red or blue in strata nearly 
vertical, or dipping 60 to 80 deg.to 
W, and therefore not parallel with 
the Mountains. Some scattered small 
conical hills through the plains, of 
Granit or Gneiss, like the Moun- 
tains.. 
Here I terminate this Survey, as 
it will intersect at Gettysburg with 
the survey made this year from S.to 
N. from the Potomac to the mouth 
of the Juniata. In going E. to the 
Susquehannah I noticed however the 
Pigeon hills, South of Oxford and 
York, which are of conglomerate 
and singular formation. 
I must conclude with some gene- 
ral remarks. 
Although only six or seven ridges 
are found in the Alleghany on this 
main road to Pittsburg in S. Penn- 
sylvania,. their number varies in 
other places, as many ridges are 
much shorter than these main ones. 
In a N. W. Direction from Lancas- 
ter and Harrisburg to Lake Erie, 24 
ridges at least are crossed, and the 
Backbone is a wide table land. 
* All these ridges appear somewhat 
like as many immense elongated 
crystals of the Globe, if we adopt the 
opinion that Crystalization has form- 
ed them: or as many long currents 
of submarine emanations and depo- 
sits, if we adopt the eruptive theory. 
It is very. singular that I met but 
few fossils on this road and explora- 
tion. This proves that they are 
scarce, Only found in some peculiar 
localities and basins, not every 
where as in the Ohio region of flat 
strata. Perhaps these Mountains 
belong to the primordial order or a 
very ancient age, rather to the tran- 
sition than the secondary. 
Boulders and water worn stones 
are also very scarce on them, only 
found in some valleys, never on the 
slopes and tops, except in the pri- 
mitive South Mountains. Extrane- 
ous stones are found there but not in 
the AHeghanies. Yet fragments of 
rocks, cubical or angular, large and 
small, are not rare, being disrupt- 
ed from the nearest rocks by con- 
vulsions, earthquakes, avalanches, 
storms and frost. 
The various directions and undu- 
lations of the strata, preclude the 
idea of a regular and quiet intumes- 
cence. They rather appear to be the 
natural result of the foliated stratum 
of the rocky layers. Either sandy 
or slaty. The Sandstones . have 
thicker layers and a disposition to 
cubical fractures. They are of all 
sorts and colors, intermingled with- 
in a small space or widely separated, 
from the coarsest gravel stone, even 
with pebbles in it to the finest quartz- 
ose granular Sandstone, the parti- 
cles of which are angular and crista- 
lized, and to the Gritstone and Free- 
stone nearly homogenous or with 
particles of Mica. In colors I 
found them white, grey, red, rusty, 
and yellow, in various hues. The 
same with the Slates, which however 
lack the white colpr and have instead 
the black. Their tendency is to thin 
layers and foliated fracture. They 
vary in hardness, some being flinty? 
and others softer, with more alumine. 
The soil of the Aleghanies appears 
to partake of the stones supporting 
it, being formed by their decompo- 
sition, with a mixture of alluvion 
carried by rains. The clay and 
marl formations are not common nor 
extensive. They as well ps the licks 
may be traced to limited formations, 
rather than wide diluvial agency. 
Iron and chert are sometimes imbed- 
ded in the Sandstone. Some valleys 
are very fertile having a deep alluvi- . 
a! soil; but the ridges are commonly 
barren, with denuded rocks, al- 
though wooded and the leaves of 
trees have added to the scanty soil. 
Although in Pennsylvania the 
highest ridges and tops of these 
mountains do not exceed 2000 or 
3000 feet, they become much higher 
in the N. and S. at their extremities 
> the N. E. called Catskill Moun- 
ins, and to the S. W. In North 
arolina, Tennessee, &c., called 
