Lake Superior Stratigraphy. — Lawson. 323 
It would seem, therefore, in view of these considerations that the 
last thing which the geological taxonomist would attempt, would be 
to separate one of these groups from the complex and sa}", ' 'It is 
post- Archaean, " and of the other, "It is Archaean. " Yet this is 
what Prof. Van Hise, by some unaccountable misconception of 
the reality of things, proposes to do. He draws the line between 
Archaean and post-Archaean at the summit of the Coutchiching. 
One phase of the confusion which arises from such a step is ap- 
parent from a glance at the table at the end of his paper. For, 
the Keewatin being placed as post-Archaean, we have this unde- 
sirable incongruity presented to us of the Laurentian rocks which 
are irruptive through it designated under an older period. If the 
Keewatin is post- Archaean the Laurentian is a fortiori so. The 
old idea of the Laurentian of the lake Superior region being a 
pre-existent basement upon which the Keewatin and Coutchiching 
have been deposited surel}' does not linger in Prof. Van Hise's 
mind ? 
In seeking the reasons for Prof. Van Hise's suggestion to call 
•one member of this great fundamental complex Archaean and an- 
other post- Archaean, or at least the influences which led him to it, 
I find two fairly distinct propositions which form to a large extent 
the basis of his argument. One is that contained in the opening 
paragraph of his paper and constituting an important factor in his 
classificating scheme, viz. , that the plane which forms the upper 
limit of the Coutchiching is a plane separating a granite-schist 
complex from an upper clastic series. This is an erroneous idea. 
The plane in question has not the significance ascribed to it. 
The granite-schist complex exists on both sides of this plane with- 
out an} T question whatever. The proposition further seems to 
imply that there is a granite-schist complex of which the schist 
constituent is different in its origin from the schists on the upper 
side of the plane. An hypothesis of that character should not, 
it seems to me, enter into a classification of geological formations 
•or groups of formations. The fact that the original character of 
certain schists of the Archaean is not fully demonstrated by the 
published evidence should not warrant their being separately 
classified as schists or " crystalline schists" par-excellence. Such 
a usage of terms carries with it the implication that there are no 
■crystalline schists in the "overlying elastics, " while as a matter 
of fact not only are crystalline schists abundant in the Keewatin, 
