75 
factory contacts have been observed ; but the ledges are so re- 
lated as to indicate that the contacts must mark faults in most cases 
atleast. The melaphyr is similar to that west of Hull Street ; and 
the conglomerate is probably that underlying the melaphyr,— the 
conglomerate of Round Hill and Conglomerate Plateau ; although 
it would be difficult to prove that the overlying conglomerate 18 
not also represented here. Dike 31, the only one observed in 
this district, separates conglomerate and melaphyr and is un- 
questionably a fault-plane. On the south, near the Hull Street 
bridge, the granite outcrops boldly, with no traces of conglom- 
` erate or melaphyr upon it. The melaphyr outcrops very near the 
granite on the north ; but, although the contact is not exposed, it 
seems impossible to doubt that a fault divides them here, as at 
points farther west. Folsom's Island probably lies on the far- 
ther side of a moderate north-south fault, which terminates these 
narrow fault-blocks and defines the abrupt eastern face of Cen- 
tre Hill. There seems to be no reason to doubt that this is 
the conglomerate underlying the melaphyr ; and since a careful 
search has failed to discover any melaphyr here, we may fairly 
suppose that it is unbroken by east-west faults, that the bedding 
planes are essentially horizontal, and that it has been elevated 
sufficiently by the north-south fault just referred to to carry the 
melaphyr wholly above the present plane of erosion. Crossing 
Strait’s Pond at this narrowest point, we find what appears to 
be the same conglomerate outcropping abundantly between the 
pond and Jerusalem Road. It extends quite up to the street, 
and immediately opposite are the ledges of granite. The beds 
strike about northwest and dip northeast BOP wo AO ДИЗ 
plain that the conglomerate runs diagonally against the wall of 
granite, from whieh it must be separated by a fault. The con- 
glomerate probably forms the whole of this rectangular area north 
of Jerusalem Road and it actually outcrops again at the extreme 
eastern end, where the small promontory projects eastward into 
the pond. In fact, when we consider in this connection the 
straightness of the granite border and the important development 
of conglomerate at the base of Green Hill, it appears at least, 
