150 
GEOLOGY OF THE FIRST DISTRICT. 
current, with varying velocities, and in different directions; as is evident from the various 
sized grains in the different layers, and the lamination of the strata of sand and gravel. Good 
examples may be seen in the sand and gravel banks half a mile to one mile below Newburgh ; 
in those at West-Point, Hudson, Marlborough, and at almost every sand and gravel bed in the 
Hudson valley (Vide Plate 27, fig. 1 ; PL 39, figs. 6, 7). Also examples of similar lamina¬ 
tion in other formations (PI. 4, fig. 12; PI. 6, figs. 3, 4, 5, 6). 
In regard to the deposits of Long island, I may perhaps be permitted to offer an hypothesis.* 
1st. The gulf stream being due to general causes, as the rotation of the earth, the influence 
of the sun upon the equatorial regions, and the general form of the coasts of the American 
continent, may be supposed to have flowed in the same general direction in former times, 
(before the elevation in mass of the quaternary, tertiary and some other depositions above the 
ocean level, from the gulf of Mexico to that of the St. Lawrence,) as at present. The gene¬ 
ral contour and topography of our country at the quaternary period having been, in the main, 
the same as at present, as is evident by the level of the quaternary deposits, the gulf stream 
must have been propelled then, as it now is, along our coast, but nearer the mountain ranges. 
Such a stream would have a tendency to cause a transport of the alluvia brought to it by 
other currents, and deposit them in the eddies caused by obstacles or oblique currents meet¬ 
ing it. 
2dly. New-England, and a small part of Eastern New-York, and probably portions of Lower 
Canada and New-Brunswick, are believed to have constituted a cluster of islands, the main 
north and south channel of which was that of the Champlain and Hudson valley. Through 
this valley, the current seems to have swept with considerable velocity, since the rocks in its 
bottom and lower parts are mostly bare, or only covered with coarse depositions, except where 
there were expansions of the valley, or such a contour of ground as to cause oblique currents, 
eddies and still water. In the Connecticut valley, the plains are regularly terraced, more like 
estuary deposits, showing the action of more regular and tranquil currents, as might be expect¬ 
ed from the greater elevation of the valleys communicating with the St. Lawrence. The 
alluvia carried south into the ocean from these and smaller valleys, would be deposited on 
meeting the gulf stream, and drifted onwards to the east and northeast, as we see on the south 
side and central portions of Long island. Long island was evidently a bar, or bank of tertiary 
and drift, before the deposition of the quaternary strata. 
If this explanation of the probable origin of the quaternary be true, that of Staten island 
may be referred to the same cause, perhaps, acting from the Hudson valley through the valley 
of the south branch of Murderer’s creek, of Smith’s clove, of the Ramapo and the Passaic 
as one current, with a branch along the southeast base of the Highlands from Stony point, 
and communicating with this current at the south line of Rockland county, where a creek 
* M. Dupont de Nemours, in his work entitled “ Quelques Memoirs sur differens sujets,” a work written about eighty-five years 
ago, says of Long island, that although not a delta in form, is one in reality, caused by the marine currents transporting the fluvia- 
tile alluvions of the Hudson, Passaic, Hackensack and Raritan rivers. He speaks of the granitic rock of Castle island, JStaten 
island, New-York island, and for about three miles along the shore of Long island from Hurlgate towards Brookland. 
