88 
I Assembly 
V. TALCOSE SLATE. 
This rock is limited in extent. It occurs in Westchester and Put- 
nam counties, forming a range of hills several miles in length. It forms 
Blue Rock Point, on the post road, between the crossing of Peekskill 
creek and Annville. The slaty laminae are parallel in direction to the 
limestone, and granular quartz rock on the east, which dip at an angle 
of from 75° to 85° to the ESE. This rock forms the principal mass 
of the hills to the NNE of Blue Rock Point for several miles. Gal- 
lows hill, a place celebrated during the Revolution, (in consequence of 
the public executions,) is a part of this range of rock. The rock is 
generally covered by soil, except where it has been denuded by water, 
or excavations for roads, &c. The soil is of good quality and produces 
fine crops. Farther northeast, this rock is rarely seen, but it passes up 
Peekskill hollow, and up a valley two or three miles west of Boyd's 
corners in Putnam county. It is very refractory in the fire, and is used 
for the in- walls of furnaces. Localities may, perhaps, be found, where 
slates for roofing may be quarried with advantage. The rock is very 
fissile, and splits in thin laminae of some magnitude. 
Diluvial scratches were observed on the out cropping edges, in many 
places, where the surface was exposed by uncovering the rock in making 
and repairing the roads. They are very distinct on the road that passes 
from Gen. Van Cortland's mansion over Gallows hill, on the western 
declivity. Like hundreds of similar localities observed last year in Co- 
lumbia and Dutchess counties, the general direction is from north 20° 
to 30° west, to south 20° to 30° east. Veins of quartz were occa- 
sionally seen traversing the talcose slate. In some places, the quartz 
was loaded with pyrites, and where the slate had decayed and the 
masses of this mineral were scattered about on the ground, they had 
the spongy texture similar to the quartz from the veins and nests in the 
slates of Columbia and Dutchess counties. The cavities are also fre- 
quently filled with oxide of iron, like the quartz in the gold region of 
Virginia and North-Carolina. No gold was however seen, and it is 
hoped that a sufficient number of fruitless researches for gold^ silver and 
coal have been made in this vicinity to deter others from future enter- 
prises of such a nature, where the expense is certain^ and the returns so 
very, very uncertain. 
The talcose slate, at its junction with the gray and whitish lime- 
stones, is highly loaded with carbon and with pyrites. The one has 
given origin to the reports and stories of valuable coal beds in this re- 
gion, and the other to the existence of gold and silver mines* 
