434 
GEOLOGY OF THE FIRST DISTRICT. 
columnar slate, the columns being from half an inch to two or three inches in diameter. A 
locality of this is about one mile northwest of the Livingston lead mine, on the road side. 
Some of the slate is black with carbon (graphic slate), and in places plumbaginous. The 
limestone is grey and subgranular ; blue and compact; and sparry. It is an extension of the 
same range described in Copake, and was traced continuously into Pineplains in Dutchess 
county, and observed to alternate apparently with the slate. 
A little to the east of Crysler’s pond in Copake, grit rock was observed in nearly horizontal 
layers dipping slightly to the east, and was immediately succeeded on the east by blue lime¬ 
stone like that near Ancram furnace ; and this underlies most of the valley east to Copake, 
cropping out occasionally through the quaternary of this valley. The limestone of Tom’s hill 
has already been described. Slate succeeds the limestone on the east, and that again is suc¬ 
ceeded by the grey and bluish limestone between Tom’s hill and the Copake ore bed. Mica 
slate (containing garnets and magnetic oxide of iron), and talcose slate, form the western base 
of Mount Washington, between the Copake ore bed and Taghkanic falls. The dip of all of 
these strata is at a high angle to the east-southeast. 
About one-quarter of a mile south of Copake, the junction of the limestone and slate like 
those of Tom’s hill and east of it, was seen ; and soon after, on the road to Boston corners, 
a small ridge of limestone, like that between Tom’s hill and the Copake ore bed, was crossed. 
The limestone continued to be seen in place occasionally to Boston corners, and thence south- 
southwest to the base of Winchell’s mountain, and seemed to skirt its eastern base, as loose 
masses were abundant on the surface, but the rock was not seen in place. Winchell’s moun¬ 
tain, which we crossed about two miles southwest of Boston corners, is composed in this 
place of slate rocks, some of which are like the roofing slate of the mountains from Copake 
lake to Hillsdale, and some is talcy, and forms the top and west side of the mountain. Lime¬ 
stone succeeds the slate at the western base of the mountain, apparently pitching under it, and 
forms the valley southwest to the Hot ground* at Punch brook, by the Livingston lead mine, 
where it is succeeded by the slate ; and these rocks alternate, or longitudinal faults cause the 
appearance of alternation, between that place and Chicomeco creek. Still farther towards 
Pineplains, the limestone is observed resting on gneiss, where both crop out through the qua¬ 
ternary. The limestone along the eastern side of the Ancram creek valley, from Hillsdale to 
Copake, seems to range down the valley east of Winchell’s mountain; while that of the western 
side of the valley spreads out in Copake and Ancram, ranging south on the west of Winchell’s 
mountain, and alternating or apparently alternating with the slate.f 
On the route from Amenia, through the central and western parts of Northeast, towards 
Pineplains, Prof. Merrick observed masses of talcose slate firmly adhering to the limestone, 
but in no case penetrating it; and talcose slate a little farther west, dipping so as apparently, 
* The name “ Hot ground" need not be understood as having any geological meaning. It is said to have been a place of much 
dissipation ; and before the time of the temperance reform, is said to have been celebrated for its flip and hot whiskey punch, 
t It is supposed that the alternation of the main masses is not real, but merely apparent, caused by longitudinal fractures and 
faults of the strata, so that they lie in successive steps, as is represented in PI. 7, fig. 4; PI. 8, figs. 1, 2, 3, 8, 9; PI. 25, fig. 2. 
