QUEBEC GROUP IN GEOLOGY. 7 
no reasonable doubt that it must be regarded as marking the junction of the Palæozoie and 
pre-Palzeozoic systems, the latter probably Huronian. 
On the geological maps of Canada, already alluded to, the strata on either side of the 
line, though very different in aspect, are run together and all included in one or other of 
the subdivisions of the Quebec group. 
On page 236 of the Geology of Canada, 1863, the differences mentioned are noticed as 
follows by Sir W. Logan :—‘ In different parts of the distribution the rocks of the Quebec 
Group seem to vary considerably in the character of the sediments composing them ; they 
present, moreover, over areas of considerable extent, two very different lithological aspects, 
being in one much more crystalline than in the other.” If to this we add that the un- 
altered portion is highly fossiliferous throughout its entire distribution, from Vermont to 
Gaspé, while no fossils have been found in the altered portion, and that the former every- 
where clearly overlies the latter, unless the dips are reversed, of which there is no evidence, 
we have, I think, the strongest possible proof of the total difference in age of the two series. 
It may also be remarked that though the rocks composing the older series are generally 
crystalline, the alteration is not so complete as to have obliterated, had they ever existed, 
all traces of the numerous and characteristic fossils so abundant in the immediately adjoin- 
ing strata of what I hold to be the inner series. 
I also wish to direct attention to the kind of structure we must commit ourselves to if 
we adopt the supposition of the identity of the crystalline and non-crystalline fossiliferous 
portions of the Quebec Group. For this purpose I have constructed a section on the Province 
line, from Lake Memphremagog to Lake Champlain. The colors are the same as used on 
the maps referred to, and shew with the extended lines of dip, the several theoretical Sillery 
basins and the intervening Levis-Lauzon anticlinals. 
The outline of the section is from actual measurement of slopes and distances, and is 
plotted on a true scale, vertical and horizontal, of two miles to one inch, or four times that 
of the map. 
An examination of this section and of the facts stated will, I think, shew the impro- 
bability of any such structure existing as is depicted on the section, and not only that it is 
unsupported, but distinctly opposed by the paleontological, lithological and physical 
evidence, and that it can only be explained by assuming anticlinal and synclinal folds and 
overturned dips to occur where there is no evidence of their existence, and certain black 
slates and limestones, now proved to be of Trenton age, to be older than the Levis forma- 
tion, and to be almost the lowest strata of tire Sutton and St. Joseph anticlinal. 
If we read pages 238 to 243 of the Geology of Canada, 1863, it will be seen that this 
assumption of anticlinal and synclinal axes and reversed dips has been carried to its utmost 
limit, and nothing can more conclusively prove than the following extracts that the whole 
theory of the structure of the Quebee Group has been founded on this assumption rather 
than on the evidence which the facts afford. 
Speaking of one of the anticlinals in the so-called lower black slates, which is desig- 
nated the Bayer and Stanbridge anticlinal, we find, page 239, the following remarks :— 
“Throughout their distribution on this anticlinal, these lower rocks consist of dark 
grey and black clay slates, often carbonaceous, with some bands of a lighter colour. The 
slates are interstratified in some parts with thin grey sandstones, and in others with thin 
