8 
MUSEUM BULLETIN NO. 22. 
and gneiss on the other side of it. Between the fault and 
Lake Huron the sediments are all conglomerate, greywacke, 
and quartzite, plainly continuations of those seen in Algoma in 
1914. So far, therefore, as the more certain identification of these 
sediments is concerned nothing was accomplished. They are 
still regarded as probably, but only probably, a part of the Cobalt 
series. 
But in the attempt to establish more certainly their identity 
another quite different relationship was revealed. The farther 
eastward the sediments were traced the more highly metamor- 
phosed did they become. The quartzite became hard and glassy, 
the conglomerate cement grew crystalline and the pebbles flat- 
tened, and the greywacke gave place gradually to a micaceous 
schist. Between Serpent and Cutler these highly altered sedi- 
ments were found to be invaded by a mass of granite which 
occupies the peninsula south of the Canadian Pacific railway. 
It was then evident that the metamorphism of the sediments 
was due to the intrusion of this granite. 
If the sediments were Huronian, it was necessary to regard 
the granite at Cutler also as Huronian or post-Huronian. This 
conclusion was supported by one other circumstance. Just 
north of Cutler the granite mass approaches to within an eighth 
of a mile of the Mississagi quartzite, the identity of which is not 
in doubt; and at this point the quartzite is unusually glassy, 
presumably as a result of contact metamorphism. If this 
glassiness in the Mississagi quartzite is really due to contact 
metamorphism, it follows that the granite must be at least 
younger than the Bruce series. 
At the end of this field investigation the evidence regarding 
the age of the granite at Cutler remained indecisive. So far as 
the present paper is concerned the net results were a rather 
strong probability that the Cutler granite mass was intrusive 
in the Huronian and a desire to find elsewhere really conclusive 
proof of this relationship. Up to the time of this investigation 
no granite intrusive in the Huronian had been found in north- 
eastern Ontario although the Huronian in many parts of this 
region had been carefully studied. The occurrence of such a 
formation on the north shore had, therefore, to be especially 
