palachian continent. Their representation on the island is found in the beds of hornblende rock.
Except
as it underwent denudation and was raised or de-pressed by secular
movements of the earth's crust, it apparently was not further changed
by any later rocks being laid down upon its primitive gneisses and
schists. As the Ice Age passed, it left it covered with drift, and it
may have been during a subsequent elevation that the conditions
imagined by Dr. Newberry supervened. For the interesting picture is
presented of the Hudson River rinding its exit into the Atlantic Ocean
some hundred miles from its present debouchment in New York Harbor at
a time when the New York Harbor was only an incident, a slight
expansion in its course seaward. Manhattan Island was then a far higher
wall on its east side, and the Palisades a loftier escarpment on the
west, and it received as an eastern tributary the waters of the
Housatonic, draining the water-sheds of Connecticut, and itself passing
between high-wooded banks, encircling the raised promontory of
Governor's Island, and mingling its tides with those of the Hudson
along the shores of Ellis' and Bedlow's Islands, which were then united
to the mainland. Further south at the opening of the present channel of
the Kill van Kull, the Passaic, swollen by the waters of the
Hackensack, united its floods with the two rivers, and the combined
volumes of water swept past Staten Island through the Narrows outward
to the distant edge of the continent, where, to-day,, eighty miles from
the present shore, the floor of the coast-plain sinks steeply to the
abysmal depths of the ocean.
The
considerations which support this surprising view are based upon the
well-known facts of the Hudson River's deeply eroded bed. Its bed lies
in the older rocks, and the gorge through which it once flowed is
indicated to-day by a submerged fissure now greatly filled up with
sediments and transported clays. The deep canons were cut in
pre-glacial days, when an immense drainage area north and east, pouring
its waters through the also deeply excavated river-course of the
