The Lambertville record. [volume] (Lambertville, N.J.) 1872-1968, 1883-07-25
THE GEOLOGY OF THE DELAWARE
VALLEY,


In lecture before the Franklin Insli-
tnte, Prof. II Carvil Lewis gave the fol-
lowing
Recapitulating the various surface for
nations here distinguished occurring at
Philadelphia we have, beginning with the
most recent:
FORMATION. Geological Age.
Recent alluyium. Modern.
Trenton gravel. Post-glaeial.
Philadelphia brick clay. Glacial.
Red gravel. Glacial.
yellow gravel. Pre-glacal
Bryn Mawr gravel. Tertiary.
In these six deposits is written the an
Gent history of the Delaware Valley. II
we read the record Alright, they tell us
that, long ago, before man was created,
when strange mammals roamed abroad,
and when all southern New Jersey lay
deep beneath the Atlantic, the waves of
the ocean broke upon the hills of Bryn
Mawr, Chestnut Hill, and Media. At the
same time, an inlet from the sea extended
over great part of the Montgomery
county limestone valley, depositing clays
holding extensive beds Of iron ore. This
region, then $50 feet lower than now, was
afterward slowly npheaved, and AZ the
waters retreated, the yellow gravel was
probably formed. Afterward, and per-
haps in consequence of this rise, the eli
mate grew colder, and glaciers crept down
from Greenland and Labrador, forming n
huge mer- de-gtace thousands of feet in
thickness. which advanced 175 feet lower
than it now is, and again the waters COW
cred the city. This time it was fresh
water of icy coldness, bearing great ice
bergs, which stranded ON the shores form
ed by the hill at Wayne junction, Bel
mont, Georges Hill, Jacksonville, Had
dington and Swarthmore. At this time
the river Delaware was 10 miles or more
in width, nearly 200 feet deep, aud, as n
roaring flood, deposited the red gravel
and left in it the records of its waves.
As the flood became more quiet, though
still filled with mud derived from the base
of the glacier, the brick clays were laid
down, the floating ice foes meanwhile
dropping their far-carried powders all
over our city.
After many thousands Of years, the
''Great Ice Age at length came to close,
the land rose to about its present level or
somewhat higher, the waters retreated,
and finally, as sudden elevations of TEN.
tperatliies thawed he glaciers still re-
| manning in the head waters Of the Della
ware, there came those last great floods
which deposited the ''Irenton gravel"
The Delaware, then SO wide as to sub
merge most of Trenton, all of Bristol, and
the river front of Philadelphia nearly up
to the State House, was again filled with
floating icebergs. The walrus played in
it's waters, while the reindeer and the
mastodon roamed ON its banks Man also
then first appeared. With habits most
probably like those of the Esquimaux,
living in most primitive ways, he hunted
and fished on the banks of the swollen
Delaware, and occasionally dropped into
the water his rude stone implements,
long afterward to be found to tell the
story of their makers.
Finally. the land began the sinking
which is now in progress, the climate
grew warmer, the Red Indian was intro
duced, and the modern era began.
This in brief, is the tale told by our
clays and gravels. Surely the long des-
pissed cobble stones Of our ill-paved streets
become more worthy of our respect when
we know their story. Still more interest
ing do they become when we learn that
they can tell us of the early history of our
own race.