New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1902-07-06
GLACIERS ON LONG ISLAND
RIDGES, SCRATCHED ROCKS AND LAKES
TELL THE STORY OF THEIR WORK.

Work done in shaping the surface of Western
Long Island by ice during the glacial period is
discussed in a recent bulletin of the ew-York
State Museum. Some of the results of this action
can easily be detected by the uninitiated they
ride drive in the suburbs of Brooklyn
Moving sheets of ice carry with them soil and
stones, which deposited the front edge,
where melting takes place. If this boundary re-
mains practically stationary for a long time the
accumulation of clay gravel will be consider
able. When. through a return of milder temper
atures or other causes the melting occurs further
back toward the source, great banks will be left
behind landmarks IF the river OF ice is COM
paratively narrow, tnen the moraine is narrow, but
if the glacier spreads out like vast sheet the
deposit along its front will be ridge of CORE
spending extent Such ridges be found near
the southern shore of New-Engsnd. Cape Cod.
Nantucket, Martha's Vineyard and Block Island
remnants of glacial moranes.
Jay Backus Woodwork. who prepared the New
York State Museum bulletin referred TO- says that
on Long Island. well further east, there are
traces of two nearly parallel ridges, which geolo-
gists call the outer and inner moranes. When
they reach the vicinity of Cold Spring. Syosset and
Roslyn, they meet and merge. From that point
onward there is only This extends little
south of westward to Prospect Park in Brooklyn
and thence across the Narrows to Staten Island.
There men who think they follow 1t still
further. Most experts have thought that the sol
ttary ridge remaining between Roslyn and the
Narrows was part of the southernmost of the two
moraines, but Mr.. Woodwork expresses the opin-
ion that it belongs to the northern one, and
lies and practically oblterates the other at the
JUNCTION n; The importance OF this suggestion lies
Nassau County and the Borough OF Queens, since
the inner moraine is believed have been formed
later than the outer one
The glacial epoch in America is believed TO have
terminated somewhere between seven thousand and
Ten thoussnd years ago and 10 have begun in the
na GZ III one hGnGred taGusand years ago Com
the long succession of vegetable and animal life
cent BIT Of history. Some of the gravels and sands
early in the glacial period Whether the SOUND was
IN existence then or not, the biologists have not
there was a second set OF deposits. These consti-
tq qte What MCGEE called the Columbia formation.
oyster Bay north OF the morane, and are repre-
nizable stage was one which followed temporary
or partial retreat of the ice, when shallow streams
valleys reaching southward. Finally. there was i!' a
F Fern4 or the ice whose halt in two positions
some little reason to think that the latter pro-
line ol the formeT MT wodworth h9R
that the second advance was attended by great ter
hrst. The retreat having been resumed it doubt
etas at Port Washington and esewhere Seem to
have been formed by Outiowing rivulets during a
The ridge from syosset and Cold Spring westward
above sea Level the Greatest eeysnp b1p leet
Hampstead Harbor Hill and Roslyn This is com
four knobs. one having height of 39I feet OF the
channels cut IN the surface by glacial streams per
maps the most conspicuous are those that reach
southwark from R1slYn, at Manhasset, and at the
southern end of Little Neck Bay. Some of the
other carving of the surface along the North
Shore. like the formation of Flushing Bay. prob
ably antedates the glacial epoch
When an ice sheet has withdrawn from a region
there are sometimes remnants left which indent
the underlying earth. The masses having melted
at length, shallow depressons visible II these
have enough clay at the bottom hold water they
constitute little lakes tarns. Several of these
may be found to the westward of Roslyn the
largest of which is called Lake Surprise bv Mr.
Woodwork. but is probably identical with Lake
Success. These pools are found in the moraine and
sometimes lie Two hundred feet above sea level
In passing over areas Of hard rock glaciers often
leave percepuble scratches, or str9. number
Of Lodges Long Island City exhibit these inter
esting markings One OF the largest beds of ex-
posed rock is adjacent TO the Queens County Court
House The scratches run from a direction con
siderably west or north and indicate that the
ment OF the Ice here from the Hudson Valley
No doubt there was a fanshaped spreading OF the
ice In the lower Hudson. Another fact which re-
yeals the same tendency is that many powders
between Brooklyn and Oyster Bay composed OF
trap rock. Identical in composition with the Pal