Marcou.] 
78 
[Nov. 7, 
with a quantity of corals and coral reefs and a thickness rather 
small if we judge from what remains of the formation at Lake 
Memphremagog and elsewhere on the line of outcrop. 
I do not mean to say that the Silurian sea of the province of 
Quebec had no communication at all with the Silurian sea of On- 
tario and New York ; but only that it had no direct communica- 
tion. The west and all the south was occupied by a continent, 
cutting the communications, but it may very well have communi- 
cated, by an indirect and very long way, through New Brunswick, 
the Gulf of St. Lawrence, the North Atlantic, the Arctic region 
and then down the great lakes of the Hudson bay territory and the 
upper Mississippi. 
After the deposition of the Silurian, another break occurred 
which resulted in an upheaval of the whole original Taconic dry 
land, with some additions of new lands ; and afterward the sea was 
excluded from the province of Quebec, except from an insignificant 
corner of the southern part of the peninsula of Gaspe. 
I close with this remark : The Champlain system and the Silurian 
system in the eastern and northern area of the province of Quebec 
are represented by narrow bands, one situated northwest of the 
province and the other southeast, enclosing between them the 
great and most important Taconic system. They may be com- 
pared to two parallel sides of the frame of a grand natural geologi- 
cal picture, which were produced by two great fissures or crevices 
of the earth’s crust ; the weakest first giving way on the line of con- 
tact of the overturned strata of the Taconic with the crystalline 
rocks of the Laurentine mountains ; and the second crevice, by a 
sort of reaction or counterpoise, giving wa}' in turn at the end of 
the Champlain deposit, forming a line of depression close to the 
crystalline rocks of the White mountains. In a word, those two 
narrow bands of Champlain and Silurian strata are due to a bas- 
cule (rocking) movement. 
Following is the tabular view of the strata in the second part or 
area of the province of Quebec, as I understood it. 
