330 The American Geologist. See 
ing for the time some of them as Huronian, we are immedi- 
ately confronted with a structural problem of a great deal of 
difficulty, i. e., the relation of these folded schists to the un- 
folded Animikie series.”* And he goes on to explain that the 
Animikie towards the north is found to lie against a belt of 
granite and gneiss, north of which again come the belts of 
folded schist; and that the two were once continuous and are 
now separated merely because of the erosion of the crowns 
of the folds between them. 
The evidence that the folded schists with truncated edges 
underlie the flat Animikie itself, and therefore cannot be con- 
tinuous with it, is to be found immediately on the shore of 
Thunder bay, as noted by Logan, but overlooked by Irving; 
and the supposition of a band of Laurentian between them 
is incorrect. 
However, since Irving’s days much has been learned of the 
Precambrian, and it has been proved that the rocks mapped 
by Logan as Huronian include two distinct series separated 
by a great unconformity; so that we have an Upper Huron- 
ian sharply divided from a Lower Huronian, which includes 
near its summit the iron ranges of Ontario and the Vermilion 
range of Minnesota. The arguments presented to disprove 
Irving’s correlation of the Huronian rocks of the Port Arthur 
region with the overlying Animikie apply only to the Lower 
Huronian, 1. e., to the iron range and its associated schists. 
It may still be argued that the Upper Huronian is the 
equivalent of the Animikie, and this is the position taken by 
professor Van Hise; who can of course no longer defend Iry- 
ing’s position, since he places the Vermilion series, which 
Irving made Animikie, in the Archean. 
If we do not admit the lithological resemblance between 
the Animikie and the Upper Huronian, it may still be said 
that the two regions are too far apart to make lithological cri 
teria useful. Those who advocate the eauivalence of the two 
may point to the fact that the so-called typical Huronian, the 
region mapped by Murray, resembles the Animikie in the 
gentle dip of the strata, which are often almost horizontal; 
while other parts, wrongfully called Huronian, have steep 
dips and are closely folded. 
* Ibid., p. 206. 
