138 
CHAMPLAIN DIVISION. 
only broken at quite regular intervals, but have been made to assume an inclined position. 
They only require to be uplifted a little more, in order to resemble the strata upon the 
eastern side of the Hudson river. 
Fig. 22. 
l s is the Calciferous group. 2, consists of the Birdseye limestone. 3 & 4, Trenton limestone. The dip is 10° south. 
Many other instances might be given, illustrating and supporting the same views, both 
in the Champlain and Mohawk valleys ; and it is perhaps proper to remark, that it is 
principally in these valleys, and other parts of the State adjacent to the Primary system, 
that the changes of the kind I am describing are found : they are scarcely, if at all, to be 
found at only a short remove from these ancient rocks. 
Fig. 23. 
The falls of Montmorenci exhibit an interesting view of the rocks, resembling the frac¬ 
ture which has been already described. It is upon the western limit of this line of fracture, 
a, b , c , d , Utica slate, Trenton limestone, Calciferous and Potsdam sandstone, in a hori¬ 
zontal position, f. Utica slate thrown down so as to dip at an angle of 60 or 70°, and 
leaning against the gneiss that forms the precipice over which the water is precipitated. 
§ 15. Thickness of the rocks of the champlain division. 
The following is the best estimate of the thickness of the individual members of this 
division, that I have been able to make : it of course applies only to these rocks as they 
exist in the State of New-York. 
1. Potsdam sandstone_ 300 feet. 
2. Calciferous sandstone__ 400 
3. Chazy limestone_ 150 
4. Birdseye limestone___ 50 
5. Isle-Lamotte marble_ 25 
6. Trenton limestone_400 
7. Utica slate--- 100 
8. Shales and gray sandstone. . 700 
9. Oneida conglomerate__ 400 
Total thickness_ 2525 feet. 
