Selwyn.] 
216 
April 3, 
CANADIAN GEOLOGICAL CLASSIFICATION FOR THE 
PROVINCE OF QUEBEC, BY JULES MARCOU. 
BY ALFRED R. C. SELWYN. 
Director Geol. and Nat. History Survey of Canada. 
It seems almost idle to attempt any discussion or explanation 
about the geology of Quebec with Mr. Marcou, 1 2 because when he 
has the boldness to assert that the Fall of the Montmorency is not 
over gneiss, in spite of the dictum of every other geologist who has 
visited and examined it, and when he persists in stating that the 
slates, shales, etc., of the Citadel Hill and of the Tresplat are un- 
der the Trenton limestone, in spite of all evidence to the contrary, 
and that the Potsdam is above the Levi’s, it becomes quite evident 
that his statements are simply expressions of his individual opinion 
and certainly have “no basis of fact” to support them. 
There are, however, one or two pertinent questions to which I 
think Mr. Marcou might be asked for a reply : 
1. Does he think Emmons, Logan and myself and many other 
geologists, who agree with us, do not know gneiss from quartzite? 
A simple yes or no to this would suffice. 
2. What are the sandstones of the Strait of Belle lie if not 
Potsdam ? 
3. If the Point Levis beds are older than the Potsdam, why have 
they never yet been discovered underlying the latter ? 
4. Page 69 (op. cit .), we are told “ we have there (Vicinity of 
Quebec) two distinct formations, one of very small extent [? thick- 
ness] belonging probably to the Trenton, and another extremely 
thick forming the hill of the city of Quebec, Point Levis and La 
Chaudiere Falls, 9 strongly upheaved and broken before the deposit 
of the Trenton limestone.” Why, if this impression is correct, is 
the Trenton limestone nowhere, in its entire course of hundreds of 
miles, seen resting on anything resembling this supposed older 
formation ? 
5. If there is no fault, as indicated by me between Levis and 
the Citadel, why do the Levis beds not reappear with their charac- 
teristic fossils on the Quebec side directly towards which they are 
striking? 
1 Proe. Bost. Soc. Nat. Hist., Vol. xxiv, pp. 54-83. 
2 Here are three very distinct series lumped together. 
