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GEOLOGY OF THE FIRST DISTRICT. 
The slate rocks are also talcose in the northeast part of Milan and northwest part of Pine- 
plains in Dutchess county, and between Whitehall and West-Poultney in Washington county. 
The rocks of this system that traverse the Highlands may be examined south of Johnsville 
in Fishkill, Dutchess county; at and near Gallows hill, and at the mouth of the Peekskill 
creek in Westchester county ; in the valley of Peekskill creek, near the east line of Phillips- 
town and west lines of Carmel and Kent in Putnam county ; and on the shore of the Hudson, 
at the limestone quarries between Caldwell’s landing and Stony point. 
Local Details. 
In Washington county, the talcose and chloritic slates were observed between Whitehall 
and Hampton villages. They were most distinctly characterized near the anticlinal axis, in 
the eastern part of the town of Whitehall and west part of Hampton. The limestones and 
calciferous rocks to the west of this axis do not seem to have been as much changed in aspect 
by the metamorphic agency, as the slate rocks along the axis, and east of it for one or two 
miles. The strike of the strata between Hampton and Whitehall is about N. 20° W. The 
position of the rocks is believed to be correctly represented on Plate 28, fig. 1. 
(A.) Primary rocks (gneiss, granite, hornblende, etc.) 
(B.) Potsdam sandstone. 
(C.) Calciferous sandstone, Mohawk limestone, etc., lying in successive steps, caused by faults 
nearly parallel to the strike of the strata. 
(T.) The quaternary deposits of the valleys. 
(X.) The slate rocks of Champlain division, changed by metamorphic agency along the axis into 
talcose and chloritic slates. 
The Potsdam sandstone does not show itself on this line of section, except near Whitehall, 
but it is very much indurated next the gneiss rocks ; and in some places on the shore of Lake- 
Champlain, within a mile of Whitehall, it seems to have been changed to a gneiss rock, or 
rather a stratified silico-felspathic rock like gneiss, only it is entirely destitute of mica. 
In Putnam, about half a mile west of the ferry across Lake Champlain, is a rock that 
appears to have once been the Potsdam sandstone, but is now a rock approaching in 
character to gneiss. It contains distinct small pebbles of white and grey quartz, like some of 
the lower beds of the Potsdam sandstone. The rock is nearly horizontal, and dips slightly to 
the west-northwest, with a steep escarpment on the east showing the layers of the rock. The 
primary, gneiss and hornblendic rocks between there and the lake dip at a high angle. 
In the northeast part of Granville, the strata of the slate were talcose and chloritic, and 
traversed by many quartz veins. 
At the falls of Pawlet river near North-Granville, the rocks also belong to the Taconic 
system. The rocks of this system range continuously from Granville through the eastern parts 
of Hebron, Salem and Whitecreek. They present all the varieties of appearance that are 
observed in the rocks of the system. The slate is sometimes the same as the slates described 
