‘a * 
Dewey on Geology of Williamstown, ge. "341 
On these two hills, it lies in large strata, inclining, like the 
mica slate, to the east and northeast, often divided by veins 
into rhomboidal masses. On the east side of Stone Hill, it is 
more granular, and may perhaps be called arenaceous quartz, 
containing a larger proportion of iron. Near the base of Hoo- 
sack Mountain, similar quartz is found, which extends round 
the north side of the Hoesack to Oak Hill, (D) which is 
wholly composed of it. It lies in rounded fragments, called 
hardheads, through the northern part of the valley, and on 
the sides of Oak Hill in huge rocks, presenting nearly perpen- 
dicular fronts from 20 to 50 feet in height, and many rods in 
ength. The strata are in some places horizontal, and in 
others nearly perpendicular. In one place it forms plates, 
from 2 to 5 feet on a side, and from half an inch to several 
inches in thickness, which are nearly perfect rhomboids, the 
edges never being perpendicular to the sides. Most of the 
quartz, except the white, yields a small portion of lime, and 
has been called calcareous quartz. Greasy quartz, rose quartz, 
hornstone and rock crystal, are occasionally found; the last in 
considerable quantity south of Stone Hill. On the stream 
Which issues from the Hopper, is arenaceous quartz of a slaty 
structure, which is an excellent stone for sharpening the 
chisels used by stonecutters. , 
4. Granular Limestone is abundant at the Cave or Falls, in 
Adams, and on both sides of the Hoosack. The Cave or Falls, 
(0) is a singular chasm between limestone rocks. A small 
stream, which appears once to have run on the surface of the 
hollow between two small elevations, has now worn a pasenge 
many feet in depth through the limestone. The chasm. — 
row, winding in its course, several rods long, and its piecing 
sides were connected, till four years ago, by a natural bridge 
of limestone. From the bridge to the water is 70 feet. There 
isa dark cavern of several feet diameter, and some passages 
into the rocks. The white marble walls, the foaming of the 
water below, the piles and irregularity of the rocks, ond the 
thick overhanging trees, make the scene very wild and ro 
esting. The limestone rests on mica slate. On the we 
bank of the Hoosack, and east base of the bill, ee seme 
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