274 ^^'^ American Geologist. ^^^i'- ^'•"^^■ 
exists in a distance of a little over a mile. It is, however, 
highly probable that the real bottom of this hanging valley 
is still higher ; but without borings to show the exact rock 
contours in the moraine-covered region above Beebe lake, the 
actual elevation of the hanging valley bottom cannot be de- 
termined. All that is certain is that its bottom cannot be lower 
than the 800 foot contour. 
Therefore, the present Fall creek occupies a valley in which 
there are three very different parts : ( i ) a distinctly mature 
upper part; (2) a post-Glacial gorge where it descends the 
hill slope from the edge of the hanging valley; and (3) a 
buried gorge section. In the first, or upper portion, down to 
Forest Home, the valley walls are moderately sloping, indicat- 
ing maturity. The exact elevation of the bottom of this part 
of the valley cannot now be determined, for, throughout most 
of its extent, the stream flows in thick drift deposits. Nor is 
it possible to determine the form or slope of the valley bottom. 
This mature valley broadens and flattens out as it nears the 
Cayuga valley, and at Forest Home suddenly changes in char- 
acter, for a large part of the remaining distance the stream 
flowing in a post-Glacial gorge, with exceedingly steep slope 
(Figs. 4-7), to approximately the level of Cayuga lake. In one 
case, at Beebe lake, the gorge is interrupted, and the valley 
broadens, where the stream cuts diagonally across a drift-filled 
gorge. This buried gorge is much wider than the distinctly 
post-Glacial gorge. 
This set of conditions is iluistrated in figures 2-7. Figure 
7 is a profile along Fall creek, showing the gentle slope of 
the upper mature portion, and the abrupt change in slope 
where the stream passes beyond the edge of the hanging valley. 
Fig. 7. Profile of Fall creek which descends the Cayuga valley slope 
along the northern boundary of the Cornell University campus. (Horizontal 
scale, % Inch to mile; vertical scale, Va inch to 1000 feet. Column of fig- 
ures gives elevations in feet with reference to sea level.) 
It also shows the location of the buried gorge. Figure 2 
looks toward the northeastern wall of the buried gorge (A, 
Fig. 7), and shows Fall creek emerging from a post-Glacial 
