Geology, &c. of the Connecticut. 49 
to afford a fine chance for observation. Let him now re- 
turn and cross the mouth of Fall river eastward, following 
up the north bank of the Connecticut, and he will find 
the same red slate, cropping out about fifteen rods, when he 
will come to another ridge of greenstone, under which the 
slate passes. If he follows the junction of the rocks ob- 
liquely up the hill, on the east side of Fall river, a hundred 
s in a northeasterly direction, he will observe the green- 
stone lying upon the slate more distinctly. Let him return 
to the bank of the Connecticut, where the sandstone slate 
passes under-the greenstone, and he will observe them both 
extending in the same manner into the stream. If he now 
go eastward along the bank of the river, he will find green- 
stone twenty rods, and then the same or nearly the same 
slate, rising on the back of the greenstone at an anzle of 
forty-five degrees. Thus will he have conclusive evidence 
of the alternation of these rocks. This alternation, cross- 
second stratum of the slate. This second ridge of green- 
stone, as already marked, extends northeasterly into Gill 
and terminates in the west part of Northfield. 
Another spot for observing the alternations of greenstone 
and the coal formation is one hundred rods south-east of 
Lyman’s tavern, on the north-east side of Mount Tom, in 
Northampton, A small stream here crosses the road, and. 
inits bed and banks several distinct beds of greenstone, 
some of them not more than one or two inches thick, may 
be observed at low water. 
In the southern part of that extensive greenstone ridge ex- 
tending from Amherst to Meriden, the sandstone of the 
coal formation may often be seen on the west side of the 
greenstone, lying underneath it. The shaft of the copper 
mine at Newgate prison passes through the greenstone and 
enters the sandstone: an r. Percival informs us (Jour. 
Sci. Vol. 5, p. 42,) that in Southington, “sometimes the 
sandstone can be very distinctly seen cropping out below 
the greenstone on the west side of the ridges.” At the 
Vor. VI.—No. 1. 
