HAMILTON GROUP. 
211 
Localities of Superposition in the Hamilton Group. 
[See Section along Cayuga lake, PI. VII.; and Coast Section of Lake Erie, PL V.] 
The section along Cayuga lake presents this group, succeeded by the Tully limestone, 
which is followed by the Genesee slate. The section on Lake Erie presents these two slates 
in contact, with merely the intervention of a calcareous band of two or three inches thick. 
These points are the two extremes of the district, and between them the Tully limestone has 
thinned out, or is only represented by a thin calcareous layer. Notwithstanding this, how¬ 
ever, we find, in all localities examined, that the Moscow and Genesee shales are entirely 
distinct, never mingling in any degree. 
The following section on the bank of Cayuga lake, at Kidder’s ferry, presents the succession 
of these rocks. 
1. Olive shale, with Pterinea, Cypricardia, Strophomena, &c. 80 feet. 
2. Coarse-grained shale, with large numbers of Fucoides__ 40 feet. 
3. A harder calcareous stratum, producing a cascade. 
4. 5 and 6. Bluish and greyish blue, very fissile shales, with 
large numbers of Atrypa, Orthis, Delthyris & Strophomena, 90 feet. 
7. Tully limestone------ H ft- 8 in. 
8, 10 and 11. Genesee slate, embracing a heavy course of sep- 
taria, 9; the portion at 11 is highly fossiliferous. Whole 
thickness .---...— 150 ft. 
12. Slaty sandstone, irregularly laminated. 
The following is a section of the conical hill on the Crooked lake outlet, being the same 
shown in the sketch at the head of the group. 
4. Genesee slate.-. 7 leel 
3. Tully limestone.. ^ “ 
2. A thin band of black slate. 
1. Bluish, fissile, and compact shale of the Hamilton group .. 60 “ 
