Finger Lake Region of Central N. Y. — Tarr. 281 
across the steepened slope to the main valley. This is certainly 
the case in lower Six Mile creek ; it also seems to be the case in 
Taughannock and in Fall creek. Since the complication of 
post-Glacial erosion obscures the evidence, it is not always 
as easy to prove this condition as it is in the case of Six 
Mile creek, where the evidence is clear and convincing. But 
it is a fact that streams of approximately the same volume, 
in approximately the same kind of rock, often have quite dif- 
ferent lower courses. In many cases, where the buried gorge 
is distinctly to one side, we have a chance to measure the 
amount of post-Glacial cutting. Thus, Buttermilk creek falls 
into the Cayuga valley over a step-fall fully 100 feet high, al- 
most flush with the steepened main valley slope ; the same con- 
dition is illustrated in many streams entering Seneca lake 
Taughannock fall, on the other hand, is three-quarters of a mile 
from the lake, from which it is separated by a broad gorge 
between 200 and 300 feet deep. To account for the differ- 
ence in these gorges it seems necessary, in the case of the 
larger gorges, like Taughannock, to appeal to excavation dur- 
ing the period of earlier gorge cutting. 
Where it emerges from the steepened main valley slope, 
the earlier gorge of Buttermilk creek has rock almost entirely 
across its mouth at approximately the 440 foot contour, or 
485 feet above the rock floor under Ithaca, two miles 
distant. With about the same degree of continuity, rock 
may be traced across the earlier Fall creek gorge, and far 
to the north and south of it. While in these cases the rock 
is not traceable continuously, its continuity is such as to elim- 
inate the possibility of the existence of a gorge of the width 
of the buried gorges. In the case of Taughannock, rock may 
be traced at lake level without a break. On both the east and 
west shores of Seneca lake, rock may be traced continuously for 
miles, absolutely eliminating the possibility of the existence of 
gorges entering the lake valley below lake level. This is much 
more clearly shown on the west than on the east side, for on the 
west side there is a continuous rock cliflf from Watkins to 
Rock stream, and farther. 
This evidence establishes a third point regarding the drain- 
age historv of Seneca and Cayuga valleys, namely that there 
is an almost, if not absolutely, uniform condition of gorges in 
