No. 275.] 
147 
and interesting. In the banks of the stream from the village of Can- 
terbury to the Hudson, nearly all colours and forms of graywacke may 
be seen. Also in the banks of the Hudson, from Cornwall landing a 
mile up the river to the mouth of the creek. Pine hill east of Skune- 
munk is a graywacke ridge, composed almost entirely of the red, slaty, 
compact and conglomerate forms. Woodbury furnace is built from the 
red stone of this hill. It makes an excellent building material, and re- 
sembles in all respects sandstone. 
Fine quarries of the blue flagging stone might be opened in Skune- 
munk mountain, and of the red, resembling the sandstone, in Pine hill. 
LIMESTONES. 
Limestones, or as they are called in many parts of the county, blue 
limestones, of these there are several. The oldest, and that which oc- 
cupies the lowest position geologically, is the sparry lime rock, or 
chequered rock. 
A stratum of this rock commences on the bank of the Hudson at 
Hampton, where Orange is bounded by Ulster county. It is about one 
mile in width from northwest to southeast. Its direction is very nearly 
SSW, passing about a mile northwest of the village of Newburgh, into 
the town of New- Windsor, and disappears beneath the surface finally, 
in the vicinity of a small body of water called Little pond, in the latter 
town. With the exception of one locality ^ its dip is to the southeast 
at an angle of 30° to 60°. The exception referred to is at Hampton, 
on the bank of the river; here this rock attains an elevation greater than 
at any other point in this stratum, and the oblique ends of the layers as 
they come out to the river bank, appear as if they had been elevated 
into a position which gives them a dip of 30° to 40° to the west and 
northwest. The elevated point of this rock at Hampton, and a similar 
but less elevated one a little below, called the 
form the northern termination of the long bay of Newburgh. 
Many of the layers of which this stratum is composed are from two 
to four feet thick; they are solid, compact, and some of them breaking 
with a perfect conchoidal fracture. The layers differ considerably in 
colour, part being a very light and part a very dark gray, and both 
traversed in all directions by narrow seams and veins of white calcare- 
ous spar. Occasionally nests of quartz crystals and brown spar are 
noticed. I have not discovered a fossil in this rock, nor could I learn 
that any have been seen by others. In a quarry of this rock belonging 
to Mr. Charles Collier, the surfaces of the layers are covered with a 
