DRIFT DIVISION. 
225 
to the southeastward in its upper part, as we see the scratches are directed on the elevated 
grounds in the eastern parts of Rensselaer and Columbia counties, and in the western part of 
Massachusetts; and this upper current would continue to influence the direction of scratches 
on the high grounds to a gradually diminishing extent to the eastern part of Massachusetts 
and Connecticut, yielding more and more to the influence of the northern current through the 
Connecticut, Merrimack and other valleys, and which would more or less impress its direction 
by scratches in the lower part of the valleys. 
The Mamakating and Walkill valleys forming the Great valley, an extension of the Cham¬ 
plain and Hudson valley, from its southwestwardly trend, would be in the natural direction 
of the set of the northwardly current. The scratches in this valley, and on the sides of the 
mountains, as well as those similarly situated in the Hudson valley, and on the island of 
New-York, conform to what we should expect from the flow of a superior current from the 
westward, and an inferior current from the northward, modified in direction by the topo¬ 
graphical features of the country. The scratches seem to have been formed by rocks frozen 
in ice, drawing a sufiicient depth of water to be influenced by both currents ; those drawing 
the most water, having been most influenced by the under current towards the general trend 
of the valley; those drawing less water, more influenced by the superior current, tending 
southeastwards obliquely across the north and south valleys. 
In describing the surfaces over which the currents have acted in the United States, I have 
considered them as acting mainly through certain valleys ; but there can scarcely be a doubt 
that they acted more or less extensively over nearly all the country, with the exception of 
Eastern Ohio, most of Pennsylvania, part of the southern mountainous portions of New- 
York, and the mountain region extending southwest through Maryland, Virginia, the Caro- 
linas, Tennessee, and the northwest corner of Georgia, into Alabama; the higher parts of 
the northern primary region of New-York, and the more elevated primary regions of New- 
England. 
Another branch of the Gulf stream (of which we have evidence that will be adduced in its 
proper place) undoubtedly flowed parallel to the trend of the mountain region across Florida, 
Alabama, Georgia, the Carolinas, Virginia, Maryland, Delaware, the eastern parts of Penn¬ 
sylvania, New-Jersey, New-York, Connecticut, Massachusetts, New-Hampshire, Maine, and 
the Provinces of New-Brunswick and Nova-Scotia. 
To the eddies formed by the meeting of this coast stream from the south, with that through 
the valley of the Lakes, the Mohawk, &c. and the St. Lawrence valley, modified also by the 
northern currents bringing ice rafts laden with rocks and earth from the north, I would ascribe 
the extensive and thick deposits of drift of New-England and Long island, and other parts 
where the warm waters of the Gulf stream thawed much of the ice brought south by the 
northern currents. It will be observed that no erratics, or scarce any, are found south or 
south-southwest of Staten island for a considerable distance from the coast, the Gulf stream 
having held there an almost entire preponderance ; while in Long island, Connecticut and 
Geol. 1st Dist. 29 
