In addition to various geological references scattered through these
pages the following facts from an American Geological Railway Guide,
by James Macfarlane, Ph.D., will be of interest.
"The State of New York is to the geologist what the Holy Land is
to the Christian, and the works of her Palæontologist are the Old
Testament Scriptures of the science. It is a Laurentian, Cambrian,
Silurian and Devonian State, containing all the groups and all the
formations of these long ages, beautifully developed in belts
running nearly across the State in an east and west direction, lying
undisturbed as originally laid down.
"The rock of New York Island is gneiss, except a portion of the north
end, which is limestone. The south portion is covered with deep
alluvial deposits, which in some places are more than 100 feet in
depth. The natural outcroppings of the gneiss appeared on the surface
about 16th Street, on the east side of the city, and run diagonally
across to 31st Street on 10th Avenue. North of this, much of the
surface was naked rock. It contains a large proportion of mica, a
small proportion of quartz and still less feldspar, but generally an
abundance of iron pyrites in very minute crystals, which, on
exposure, are decomposed. In consequence of these ingredients it soon
disintegrates on exposure, rendering it unfit for the purposes
of building. The erection of a great city, for which this island
furnishes a noble site, has very greatly changed its natural
condition. The geological age of the New York gneiss is undoubtedly
very old, not the Laurentian or oldest, nor the Huronian, but it
belongs to the third or White Mountain series, named by Dr. Hunt the
Montalban. It is the same range which is the basis rock of nearly all
the great cities of the Atlantic coast. It crosses New Jersey where it
is turned to clay, until it appears under Trenton, and it extends to
Philadelphia, Baltimore, Washington and Richmond, Va., and probably
Boston, Massachusetts, is founded on this same formation.
* * *
Oh, river! darkling river! what a voice
Is that thou utterest while all else is still!
_William Cullen Bryant_.
* * *
"On the opposite side of the river may here be seen for many miles the
Palisades, a long, rough mountain ridge close to the water's edge. Its
upper half is a perpendicular precipice of bare rock of a columnar
structure from 100 to 200 feet in height, the whole height of the
mountain being generally from 400 to 600 feet, and the highest point
in the range opposite Sing Sing 800 feet above the Hudson, and known
as the High Torn. The width of the mountain is from a half mile to a
mile and a half, the western slope being quite gentle. In length it
extends from Bergen Point below Jersey City to Haverstraw, and then
westward in all 48 miles, the middle portion being merely a low ridge.
The lower half of the ridge on the river side is a sloping mound of
detritus, of loose stones which has accumulated at the base of the
cliff, from its weathered and wasted surface.
"Viewed from the railroad or from a steamboat on the river, this lofty
mural precipice with its huge weathered masses of upright columns of
bare rock, presenting a long, straight unbroken ridge overlooking the
beautiful Hudson River, is certainly extremely picturesque. Thousands
of travelers gaze at it daily without knowing what it is. This entire
ridge consists of no other rock than trap traversing the Triassic
formation in a huge vertical dike. The red sandstone formation of New
Jersey is intersected by numerous dikes of this kind, but this is much
the finest. The materials of this mountain have undoubtedly burst
through a great rent or fissure in the strata, overflowing while in a
melted or plastic condition the red sand-stone, not with the violence
of a volcano, for the adjoining strata are but little disturbed in
position, although often greatly altered by the heat, but forced up
very slowly and gradually, and probably under pressure. Subsequent
denudation has laid bare the part of the mountain now exposed along
the river. The rock is columnar basalt, sometimes called greenstone,
and is solid, not stratified like water-formed rocks, but cracked in
cooling and of a crystalline structure. Here is a remarkable but not
uncommon instance of a great geological blank. On the east side of
this river the formations belong to the first or oldest series of
Primary or Crystalline rocks, while on the west side they are
all Triassic, the intermediate Cambrian, Silurian, Devonian and
Carboniferous formations being wanting. This state of things continues
all along the Atlantic coast to Georgia, the Cretaceous or Jurassic
taking the place of the Triassic farther south.
* * *
Like thine, O, be my course--nor turned aside,
While listening to the soundings of a land,
That like the ocean call invites me to its strand.
_Mrs. Seba Smith._
* * *
"Montrose to Cornwall. This celebrated passage of the Hudson through
the Highlands, is a gorge nearly 20 miles long from 3 miles south of
Peekskill to Fishkill, and is worn out of the Laurentian rocks far
below mean tide water. The hills on its sides rise in some instances
as much as 1,800 feet, and in many places the walls are very
precipitous. The rock is gneiss, of a kind that is not easily
disintegrated or eroded, nor is there any evidence of any convulsive
movement. It is clearly a case of erosion, but not by the present
river, which has no fall, for tide water extends 100 miles up the
river beyond the Highlands. This therefore was probably a work mainly
performed in some past period when the continent was at a higher
level. Most likely it is a valley of great antiquity.
"Opposite Fishkill is Newburgh, which is in the great valley of Lower
Silurian or Cambrian limestone and slate. North of that, on the west
side of the river, the formations occur in their usual order, their
outcrops running northeast and southwest. On the _N. Y. C. & H. R. R. R._,
on the east side, the same valley crosses, and the slates from
Fishkill to Rhinebeck are about the same place in the series;
but being destitute of fossils and very much faulted, tilted and
disturbed, their precise geology is uncertain. See the exposures in
the cuts at Poughkeepsie. The high ground to the east is commonly
called the Quebec group.
* * *
Amid thy forest solitudes one climbs
O'er crags, that proudly tower above the deep,
Along the verge of the cliff, and he can hear
The low dash of the wave with startled ear.
_Fitz-Greene Halleck._
* * *
"A series of great dislocations with upthrows on the east side
traverse eastern North America from Canada to Alabama. One of these
great faults has been traced from near the mouth of the St. Lawrence
River, keeping mostly under the water up to Quebec just north of the
fortress, thence by a gently curving line to Lake Champlain or through
western Vermont across Washington County, N. Y., to near Albany. It
crosses the river near Rhinebeck 15 miles north of Poughkeepsie and
continues on southward into New Jersey and runs into another series of
faults probably of a later date, which extends as far as Alabama. It
brings up the rocks of the so called Quebec group on the east side of
the fracture to the level of the Hudson River and Trenton.
"Catskill Mountains. For many miles on this railroad are beautiful
views of the Catskill Mountains, 3,800 feet high, several miles
distant on the opposite or west side of the river, and which furnish
the name for the Catskill formation. The wide valley between them
and the river is composed of Chemung, Hamilton, Lower Helderberg and
Hudson River. The geology on the east or railroad side is entirely
different.
"Albany. The clay beds at Albany are more than 100 feet thick, and
between that city and Schenectady they are underlaid by a bed of
sand that is in some places more than 50 feet thick. There is an
old glacial clay and boulder drift below the gravel at Albany, but
Professor Hall says it is not the estuary stratified clay."
* * *
There has that little stream of water been playing among the hills
since He made the world, and none know how often the hand of God
is seen in a wilderness but them that rove it for a man's life.
_James Fenimore Cooper._
* * *