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already been cited as proving a displacement between them ; 
and the same reasoning applies with equal foree when we pass 
from Great Hill to Conglomerate Hill. The Great Hill con- 
glomerate is extremely irregular, varying abruptly and re- 
peatedly from fine sandstone to a mass of granite and melaphyr 
bowlders one to three feet in diameter. Granite pebbles and 
bowlders are numerous, but usually rounded. Felsite and 
melaphyr are also. abundant, but the latter is never amygda- 
loidal. The conglomerate is jaspery at most points—red jasper, 
but so highly ferruginous as to be perceptibly less bright and 
hard than that in the more western hills. It occurs, however, 
in the same way, and lends support to the view that this con- 
glomerate should be correlated with one of the three lower or 
basal beds. The conglomerate is thoroughly indurated through- 
out, although this is most noticeable in the sandstone layers, 
which are as hard as quartzite, but always red, felsite debris 
largely predominating. The dip is flat as a whole, but vari- 
able,—horizontal at some points and inclined 15°-20° at others, 
especially near the granite. The normal dip appears to be east 
to southeast and not above 5°; and the exposed thickness of the 
conglomerate must be nearly the height of the hill or at least 
sixty feet. 
There is no overlying and there appeared at first to be no 
underlying melaphyr or porphyrite ; and the exact correlation of 
this conglomerate seemed a hopeless task, until I came to study 
in detail the phenomena presented near the contact with the 
granite, on the southwest corner of the hill. It is evident at 
a glance that the main body of conglomerate does not rest 
upon the granite, but is faulted down against it, the boundary 
fault crossing the hill at this point, and with essentially the 
same result as on the west side of the marsh. The granite 1s, 
however, capped by several feet of conglomerate at this point ; 
and the fault, which is very clearly exposed, hades irregularly 
to the north. Following it down carefully we come finally, 
some six feet below the top of the granite and about fifteen 
