Richland beacon., 1888-03-24
A PREHISTORIC HUDSON.
II Took i'm the HOusat OniC and jersey
Rivers aud Emptied Eighty Miles
ont 20 Sea

"The Geology of New York and It's
Environs' was the title of q most inter
esting paper read by Prof. Daniel s.
Martin, before the New York Academy
of Sciences, in Hamilton Hall, Columbia
College.
After reviewing the great deposits in
the vicinity Of New York of gneiss,
brown sandstone. serpentine, trap and
sand, gravel and boulder beds of the
Glacial period, when, hundreds of thou
sands of years ago the whole of the
northern portion of the United States
was covered by an immense sheet of ice
stretching northward to the Pole, Prot.
Martin said:
with regard to the changes of level
since Tertiary-the last great geo.
logical age-there are interesting evil
dcnces of various kinds in and around
New York, though not conspicuous to
the eye. The great and long duration
which preceded, in part. at least, &C
companied the Glacial period, has left
its unmistakable record in the deeply
excavated river valleys on both sides of
the city, and in the depressed channel
revealed by "oundings. which shows us
that the Hudson then reached the sea
some eighty miles southeast of the pres
ent mouth Of the harbor.
'Prc glacial New York presented a
very different aspect from what it does
now. and one far more bold and roman
tic in its scenery. The island itself was
/ a rocky promontory, some 300 feet high,
and the wall of the Palisades on the
| west side OF the Hudson rose to 700 feet
while in the gorge between these lofty
shores the river flowed in its present
course, though far below.
"On the east of the island, between 1t
and the rocky heights which now are
sunk and buried beneath the drift-or
debris of the ancient glacier-of North
western Long Island, another river
flowed to Join the Hudson from the
northeast. This river was n continual
ton of the Housatonic and carried the
drainage of southwest New England,
along the bed of the present Sound and
East River. These streams united in
the upper bay and were joined by the
rivers from New Jersey, and the great
current flowed on through lofty rocky
islands, where now are the gentle hills OF
Staten Island and the low inlets of the
plain, through which it pursued its
course nearly 100 miles to the ocean.
"Thcn slowly came on the Great Ice
Age; and the great ice mantel covered
all and left its impress 50 plain that 'ht
who runs may read Finally the con
ditions changed, and the great elevation
was followed by depression to the pres
cnt level, and then by subsistence below
it. In this Champlain depression
though scarcely sufficient at this poin
to have traces over the island, yet thu
deeply-worn river channels were fil,eC
up to a depth of 300 to 400 feet; so tina
now the Hrdson-like most of the river
of the North-Rowed in its old course
indeed, but far above its former rock,
bed. The same cause has made tn,
tributary streams of New Jersey ant
Connecticut independent rivers, an'
spread the broad New York bay and tn
tide channels of the East River, and tn
quiet waters of the Sound, over a wild
area of pre- glacial land, and the oceal
over all the literal coast plain. Agail
there was an elevation, but at the presen
time the movement seems to be agai
downward, and the sea is slowly on
croaching on the land.
"In the projected tunnel beneath tn
Hudson River it is of interest to not
that the work, though carried on man
wards below the bed of the river, wa
entirely in hard clay, with recent marin
shells-the latter portion of the pos
glacial filling up the channel. Nowher
was rock encountered or approached
and the same is true of the excavation
for the caissons on which were laid tn
massive piers of the Brooklyn Bridge.