28o The American Geologist. ^^^y, i904. 
Fig. 23. Cross section of Seneca lake three miles north of Watkins. 
(Scale same as Fig. 7.) 
through gorges to the main valleys, there is very generally 
a notable change in the slope of the main valley walls. This 
change in slope is usually near the 800-900 foot contours. 
The fact that this change, though general, is not universal is 
undoubtedly significant. 
The Buried Gorges: None of the large tributary valleys 
so far studied, and few of the smaller ones which enter the 
southern half of the Seneca and Cayuga valleys, are without 
evidence of the existence of gorges which antedate the last 
advance of the ice. In some cases these earlier gorges descend 
the steepened valley slope along a path entirely apart from that 
followed by the post-Glacial gorges. This condition is illus- 
trated by Watkins glen, where the stream follows approx- 
imately the same course as the earlier gorge up to the edge 
of the steepened slope, then, just above the point where the 
railroad bridge crosses the upper part of the glen, turns to 
the south and follows a post-Glacial gorge to the town of 
Watkins. It is also illustrated by Buttermilk creek, which 
likewise has approximately the same course as the buried 
gorge up to the edge of the steepened slope, then turns south- 
ward and descends to the Cayuga valley through a post-Gla- 
cial gorge. In the case of Buttermilk creek the earlier gorge, 
much broader than the post-Glacial gorge, causes a decided 
sag in the hillslope, in which both walls of the moraine-filled 
gorge are in places shown (older gorge Fig. i.) 
In other cases the streams follow the approximate course 
of the buried gorges clear down to the main valley. Six Mile 
creek illustrates this condition. This stream alternately enters 
the buried gorge, forming broad amphitheatres, and where it 
for a short time leaves the earlier gorge, crosses spurs of rock 
in narrow post-Glacial gorges. 
A third condition is where a stream enters the earlier 
gorge, clears out part or all of its drift-filling, and follows it 
