s 
ROCK RUINS. 
Section of the strata along the Niagara River, from Lake Ontario to Lake Erie. 


Lake Ontario. 

EXPLANATIONS. 
1, Red shaly sandstone and marl, which may be seen in 
thé bank of the river at Lewiston (j). 
2, Gray quartzose sandstone. 
3, Red shaly sandstone like No. 1 (with thin courses of 
sandstone near the top). 
4, Gray and mottled sandstone, constituting, with those 
6, Compact gray limestone, which with No. 5 consti- 
tutes the Clinton Group at this place. 
7, Soft argillo-calcareous shale. 
8, Limestone. 
8', The upper thin-bedded limestone, which, together 
with 7 and 8, constitutes the Niagara group. 
9, Onondaga salt group of shales and marls, including 
the hydraulic limestone, or beds of passage to the 
next rock. 
10, Onondaga and Corniferous limestones. 
All these layers, from 1-10 inclusive, belong to the 
upper Silurian system. 


h, g, f, d, ¢, j, This line represents the present surface 
of the river from Lake Erie to Lewiston, a distance 
of about twenty-one miles. 
h, g, The present surface of the river, between Lake 
Erie and the Falls. 
d, f, The perpendicular fall, over the Niagara limestone 
and shale. 
f, g, The rapids, where within a mile there is a descent 
of fifty-two feet over the upper thin-bedded portion 
of the Niagara limestone. 
c, The whirlpool. 
d, c, j, Present level of the river where it has cut its 
way down through all the layers from 1 to 8! inclu- 
sive. 
i, k, The position of the falls and rapids after a reces- 
sion of two miles. 
a, i, d, Future level of the river bed, as the falls gradu- 
~~ 
fessor Hall’s Report on the Geology of New York. 
. 

