Wave-cut Terraces in Keuka Valley 
41 
Luther to be 75 feet thicks® This formation is above the terraces 
in question, so its characteristics do not concern us. 
It appears, therefore, that there is no factor in the stratigraphy 
of this area to account for the marked benches. No conditions 
could be more favorable for registering the diflPerential effects of 
weathering than the topography formed by this peninsula of rock 
dividing the two arms of Keuka Lake. 
CLIFFS IN KEUKA VALLEY. 
The succession of post-Wisconsin high level lakes that formerly 
occupied this region has been worked out by Fairchild. He desig- 
nates the overflow channels of the principal stages, correlates the 
deltas, and points out some localities of wave-work. 
The terraces and cliff^s which occasion the present paper have 
been studied in some detail along the flanks of Bluff Point. Ter- 
races apparently of the same age have been noted elsewhere on 
the walls of Keuka valley, but have not been critically examined. 
The most obvious reason for not associating these cliffs and 
terraces with the work already done is the fact that they are over- 
lain and intersected by lines of Wisconsin drift. This drift is in 
place, and so far as observed, shows no evidence of wave-work 
along the planes of the terraces in question; furthermore, the drift 
is particularly well developed where it crosses the terraces (fig. 3). 
These terraces, designated by numerals, are described in regular 
order ascending from present lake-level. 
No. I. This is not a clear case. For some distance southward 
from Keuka Park is a bench and terrace; the relation here is con- 
spicuous enough, but the cliff consists of the hard beds in the 
Cashaqua already alluded to; it stands about 70 feet above the 
lake, but descends southward. There is, however, a persistent 
suggestion of a bench southward to vicinity of Dunning’s, not a 
continuous shoulder, but a- recurrence of over-steepened short 
slopes forming a plane that ultimately dips beneath the water. 
Ihid.^ p. 49, 1906. 
The Amer. Journ. of Science^ vol. vii, pp. 255-256, 258, Bulletin Geoh 
Soc. Am.y vol. X, pp. 4-41, 1899. 
