Marcou.] 
206 
[Jan. 2i, 
of the Utica slates dipping westward instead of eastward. It is 
evident that the group of slates called B in the section, seventy- 
three feet thick, belongs to the Upper Trenton and Lower Utica, 
and has fallen into the ravine by a landslide, between the wall of 
quartzite on one side and the black and gray slates of the Upper 
Taconic on the other. 
After passing the confused stratification indicated on the section 
figure No. 3, we come to a great thickness of black and gray 
slates, with now and then a few thin beds of calciferous-marls in- 
terstratified, dipping sixty degrees to the east-east-south, like all 
the great masses of strata of the whole Taconic system ; and 
which form the hill extending from the ravine to the St. Law- 
rence river. Only close to the St. Lawrence river there is a 
small tongue 1 of the Upper Utica slates containing: Triarthrus 
Becki, Endoceras proteiforme and Leptobolus insignis, which is the 
remains of another landslide preserved above or in the S wanton 
slates of the Taconic system. 
1 have given (fig. No. 2) a section sent to me by Mr. Selwyn. 
Director of the geological survey, the 7th of June 1884; just at 
the time that he was publishing his: “Diagram section of sup- 
posed structure from Montmorency falls to the Island of Orleans,” 
in his: “Descriptive sketch of the physical geography and 
geology of the Dominion of Canada,” page 14, Montreal, 1884. 
As Dr. R. W. Ells, in his “Second report on the geology of 
the province of Quebec,” p. 22, Montreal, 1888, says that his ob- 
servations “clearly” maintain the conclusions stated by Logan and 
subsequently by Dr. Selwyn ; it will be easy for the reader and 
future practical observers in the field to compare and see the 
difference existing among geologists on the geology of Montmor- 
ency falls. 
On the western or right side of Montmorency fall, at a distance 
of only thirty or forty yards from the river Montmorency, there is 
an example of a Trenton limestone landslide. A large mass of 
Trenton rests on asperities of the quartzites, at an angle of eighty 
iThe expression of “tongue of Utica slates’’ is due to the Abb6 Laflamme, Profes- 
sor of Geology at the Laval University of Quebec. It is a happy word, which expresses 
in the most satisfactory way a phenomenon constantly met with in the province of 
Quebec, near the contact of the Champlain system with the Upper Taconic strata, 
brought about by landslides due to great erosions and denudations. Ann. Report , 
Geol. Surv. Canada, vol. ii, new series, 1886, p. 37, A, Montreal, 1887. 
