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BULLETIN OF THE LABORATORIES 
In the light of the facts presented beyond it seems that the danger is 
sufficiently obvious in attempting to generalize on the basis of observa- 
tions covering a portion of a district and still farther of dogmatizing 
on the basis of such a description as the above. In the first place our 
study makes it appear that McFarlane, in his hasty examination, failed 
to distinguish between the dykes and bosses of eruptive diabase, which 
break through the granite as well as the schist, and the metamorphosed 
schist itself. Having made this strange error, consistency required 
that the obviously stratified schists should be also included, so it be- 
came easy to consider the trap as a phase of the schist, all being neces- 
sarily eruptive. Had he gone five miles farther east he would have 
encountered schist conglomerates with water-worn bowlders of gneiss, 
etc., and would have found it necessary to include them also in the 
the curious group of igneous rocks which he calls greenstones. The 
confusion above referred to is the more strange because at this point 
there is actually no difficulty in distinguishing the eruptive granite 
from the eruptive trap and the metamorphic schist. At other places 
all the explorer’s acumen and care is taxed to distinguish the schists 
from the dyke-matter, there having been extensive interaction between 
them. It would seem that from the above statements it should be ob- 
vious that a careful and detailed study of even a limited area might 
serve a better purpose than a cursory examination of a large field. 
With this in mind the short time at our disposal was employed in care- 
fully working out the details of the geological structure of a small area 
about Michipicoten bay where, fortunately, a very considerable varie- 
ty of rock may be encountered within easy distance. Judging from 
the brief accounts of this region published, we expected here to find 
the three formations in doubt in close juxtaposition. Pitching- camp 
at Dog river, the coast was explored foot by foot in each direction as 
time permitted, while excursions into the interior enabled us to ob- 
serve the substantial uniformity of strike and texture for several miles 
inland. We proposed to ourselves the following questions: (i) 
What distinct formations may be recognized, both lithologically and 
stratigraphically ? (2) What is the relative position and age of each ? 
(3) What has been the source of the material and what the circum- 
stances of deposition ? (4) What alterations in composition and posi- 
tion during the subsequent changes? (5) How may the present to- 
pographical features be explained ? 
It soon became evident that we had to deal with three easily rec- 
