Shepherdstown register. [volume] (Shepherdstown, Va. [W. Va.]) 1849-1955, 1912-09-12
History OF The Potomac River.

| ne RredI fOIOIlldC ROlSc WdS uOt d-
ways, as it is to-day, one Of the most
beautiful and picturesque OF friver valleys.
The United States Geological Survey has
recently published a geologic folio de-
scribing about 400 square miles, includ-
ing portion OF the Potomac Valley-the
areas known as the Pawpaw and Han
cock quadrangles, in Pennsylvania, Mary
land, and West Virginia. This folio
(No. 179), which was written by George
w. Stose, contains a most interesting
account of the gradual cutting down by
the river Of this deep gorge during thou
sands of years.
The area is located in part ct the Po-
tomac Valley where the river winds in
great curves through deep gorge with
densely wooded slopes. AS the railroad
traveller swings around these sharp bends
which almost meet before they reverse
and realizes that il takes three times as
long to ride between two points as il
would to 60 In a straight line, he may
wonder how the river acquired such a
course.
In view from the tops Of the ridges,
it can be seen that many OF the hilltops
are flat and of about the same altitude,
and that if the valleys were filled up they
would form a nearly level plain. This
feature is also excellently shown by the
topographic map which forms a port OF
the folio. Mr.. Stose says that many
thousand years ago the Potomac flowed
toward the sea upon this plain, which at
that time was much lower in altitude-in
fact, so near the level of the sea that the
stream was very sluggish and wandered
about in its valley, as is the custom OF
streams with low grade, such as the Miss
issippi. Later, when the interior OF the
continent was somewhat elevated, the
streams became "rejuvenated" and cut
down their channels, first into the soft
detritus which had accumulated in the
flat valley and eventually into the hard
rocks beneath. AS the continent rose
still higher, they cut deeper into the
rocks, and, as a result, the Potomac IS
now deeply intrenched in these winding
gorges. One stream in the area, how
ever, is making change by cutting of a
meander and taking short cut through
hill, producing a beautiful cataract.
This stream is shown in the Photographic
illustrations of the folio, as are also the
remnants OF the elevated plain on the
hilltops, once the valley Of the Potomac.
Other marvellous features which the
traveller may observe from the car Win
dow in passing through this area are the
great rock folds. One arch OF rock that
has been truncated by the river and is
visible from the train and canal is OF such
interest to geologists that il has attracted
visitors from all parts of the world and is
illustrated in most text books on geology.
Other folds, not visible from the train but
readily accessible to those interested,
have the form of great saw teeth rising
above the crest of hill. All these folds
are well illustrated in the folio. These
rock folds are the record OF the great
mountain making forces which crushed
and folded the rocks as they were raised
out OF the sea.
Many of the rocks are full OF we'll
preserved fossil shells. Some that have
long, banded, fluted wings are called but
terflies by the natives. How did they
| get into the rocks and what do they
mean2
These fossils were shells OF living
creatures that inhabited the sands and
muds OF a sea that covered this region
long ages ago. All the rocks now at the
surface OF this area are hardened sedi-
ments that were deposited on the shore
and on the bottom Of the sea, and the
shells of the animals that lived in these
waters were buried in these sediments
and were hardened with them. Now we
find them beautifully preserved in stone.
The beauties and wonders Of nature
are abundantly displayed in this region
and no one should go on a camping, fish
ing or touring trip TO it without copy Of
this folio in his possession, the better to
understand what he sees. A copy OF the
Pawpaw-H Hancock folio may be obtained
from the Director of the United States
Geological Survey at Washington for 25
cents, or in more compact form. called
the field edition. with folded topographic
and geologic maps in pocket. for 30
cents.