Marcou.] 
62 
[Nov. 7, 
to Gaspe, a distance of 500 miles, and on an average of twenty- 
five miles broad, to the Lower Silurian (Champlain system)because 
“ these strata hold a large number of genera and species of char- 
acteristic Lower Silurian fossils ” (no name or list of fossils of any 
kind given). That classification is made on what Mr. Selwyn calls 
“ purely stratigraphieal considerations,” for he deprecates “pal- 
aeontological stratigraphy.” Notwithstanding his “ principle,” his 
classification is based solely on the “ large number of characteristic 
Champlain fossils,” and is contrary to lithology and stratigraphy, 
and certainly also against a well digested palaeontology. 
The structure of “ this fossiliferous belt” is “ a broad, crumped 
and folded synclinal,” with “ the characteristic Pointe Levis lime- 
stone conglomerates and associated graptolithic shales coming up 
near the base on both sides.” He admits, however, “ a number 
of local and unimportant overturn dips, but there seems to be no 
evidence whatever of a general inversion of the strata.” 
Then Mr. Selwjm speaks of the St. Lawrence and Champlain 
fault or overlap, bounding this belt on the northwestern side, which 
places in contact what he calls “ the even-bedded shales and lime- 
stones of the Lorraine shales’ group with the crumped and twisted 
strata of” the Quebec group of Logan. “ The line of this dislo- 
cation or unconformity — whichever it may be — has been supposed 
to pass to the rear of the Quebec citadel. This I hold to be a 
mistake, and I think it can be distinctly shown that it passes from 
the southwest end of the Island of Orleans under the river and be- 
tween Pointe Levis and Quebec ; it appears again on the north 
shore of the St. Lawrence about one mile north of Pointe Pizeau, 
passes north of St. Foy and then in a direct course to where it 
again crosses the river southwest of Cape Rouge.” 
As stratigraphy is the strong point claimed by both Logan (“the 
most able stratigraphieal geologist of the American continent”) 
and Mr. Selwyn (“ a stratigrapher of forty years standing”), it is 
important to show the divergence of opinions between such experts 
and the character of the proof used by them. 
Logan says : “from the physical structure alone no person would 
suspect the break that must exist in the neighborhood of Quebec, 
and without the evidence of the fossils, every one would be au- 
thorized to deny it . . . There must be a break ;” and he points 
out its course and its character, calling it “ an overturn anticlinal 
fold with a crack and a great dislocation running along the sum- 
