DRIFT DIVISION. 
189 
New-Lebanon, Stephentown, Berlin, Petersburgh and Grafton. On the south side of Fog 
hill in Austerlitz, and on the rise of land north of Green-river village, blocks twenty feet in 
diameter of this rock were seen. On the western slope, and on some of the most elevated 
parts of the East mountain, east of the Shaker villages in New-Lebanon, the surface is almost 
covered in some places with blocks and boulders of limestone, as stated by Prof. Briggs. I 
have frequently observed, even on the most elevated grounds on this range of mountains, and 
on the West mountain range, abundance of boulders and blocks of the rocks at no great dis¬ 
tance, generally from a northwardly direction. 
In the Lebanon valley, between Chatham and New-Lebanon, the quaternary deposits are 
terraced, and the quaternary clays are covered by a thick deposit of the upper drift, contain¬ 
ing boulders of the rocks of the adjacent mountains, with an occasional one of granite, labra¬ 
dor feldspar, etc. from the northern part of the Hudson and Champlain valley. The deposits 
of drift above the clay beds, are in some instances sixty to one hundred feet in depth. 
Boulders on the heads of the Delaware. 
Boulders of granite and gneiss, weighing from two hundred to two thousand pounds, 
were seen in the valley of Betty’s brook, a tributary of the Delaware, in the town of Kort- 
right, Delaware county, near the residence of Dr. Marshall, who had long noticed them as 
being erratic blocks and boulders. They are at an elevation of at least two thousand feet 
above tide water, and near the head of the valley in which they are situated. They are not 
very uncommon towards the summits of the valleys where streams flow in opposite directions, 
in Delaware, Ulster, Greene and Schoharie counties; and as these rocks are so different in 
their aspect from the common rocks of those counties, they frequently attract attention. Such 
rocks are found in place only in the country north of the Mohawk valley, and in the Highlands 
of the Hudson. 
Boulders, etc. of other parts of New-York. 
Prof. Vanuxem has shown by facts he has related, that the upper drift of the bottom of the 
Mohawk valley, from Utica down, is from a westerly direction ; and also that the drift com¬ 
posed of primary and other rocks forms terraces and irregular hills towards the heads of 
the north and south valleys which branch to the south from the great valley of the Mohawk, 
and that the principal accumulations are towards the heads of those valleys,* and that all 
or nearly all the materials are from rocks in place in a northwardly direction; and that 
currents have flowed through these valleys from the north, into the tributary valleys of the 
Susquehannah.t He has also shown that the distribution of the drift in the Black river val¬ 
ley (which in fact is one extension of the Mohawk valley through West-Canada creek to Lake 
Ontario) is mostly from the north, except the primary boulders from the mountains on the 
Final Report on the Geology of the Third District of New-York, p. 219. 
t Id. p. 235 to 237. 
