Marcou.] 
218 
[Jan. 21, 
that both falls are made among slates of the Middle Taconic sys- 
tem ; just as Kakabeka’s fall on the river Ministiquia, north-west 
of Lake Superior, has been referred by me to the black slates of 
the Lower Taconic. 
Conclusions. — We can assume the following facts as well es- 
tablished for the geology of the vicinity of Quebec : Two dif- 
ferent systems of Lower Paleozoic rocks are found there. 1st, the 
Champlain system, almost horizontal with remains of landslides, 
near the actual edge of the system, which has left fragments or 
spindles ( fuseaux ) of Trenton limestone in ravines or perched on 
asperities of quartzites, and tongues of Utica slates lying over 
Taconic slates. Denudation and erosion hasr educed the Cham- 
plain system of the vicinity of Quebec to very narrow limits, as 
well horizontally as vertically. 2d, the Taconic system is al- 
ways strongly dislocated, with a general dip south-eastward, 
under an angle of an average of sixty degrees. As the whole 
system has been overturned, and is mainly formed of an enor- 
mous mass of slates, at least 20,000 feet thick, there is in such a 
mass many small faults ( faillotes ) which do not affect by any 
means the whole system, or any portion of it ; and also many 
local folds, the most conspicuous being Pointe-Levis and the 
Citadel of Quebec. But nowhere do those small faults or local 
folds repeat on a great scale the different groups of the Upper, 
Middle and Lower Taconic. 
The upper part of the Taconic system, 6,000 feet thick, is 
formed by the strata which cover the whole ground from the 
foot of Montmorencjf fall to near Pointe-a-Pizeau, Victoria hotel 
at Levis, and half-way between Beaumont and Pointe-Levis. In 
that great mass of 6,000 feet of strata, two great groups may 
be made for convenience. The first upper 3,000 feet are called 
“Quebec-city group” or “Swanton slates” of Vermont. In it 
are sporadic apparitions of forms of fossils of the second fauna 
mixed with supra-primordial forms, at only three or four places 
in the vicinity of the Plain of Abraham, as at Highgate-spring in 
Vermont. But generally the Quebec-city group or Swanton slate 
is bare of fossils. 
The lower 3,000 feet of the Upper Taconic are well developed 
at Pointe-Levis, under the Chateau St. Louis and the upper por- 
tion of the old town of Quebec and under the citadel, extending 
along the northern shore of the St. Lawrence as far as Mount 
