Frank Carney 
406 
Crystalline Erratics. A few areas where the foreign element 
of the drift is large, and the individual bowlders also of unusual 
dimensions, will be referred to. East of the highway leading 
northward from Sempronius several very large crystallines may 
be seen; at the head of the short valley extending westward from 
Locke, the drift knolls are dotted with erratics; about one mile 
northeast of Benson Corners, at the general altitude indicated by 
the 1400-foot contour, the bowlders are numerous and large. 
Another area of abundant foreigners is the slope of the hill southeast 
of Como; a Bench Mark of the United States Geological Survey 
has been fixed in a large bowlder in the field a short distance from 
the highway which skirts this slope. 
A few bowlders conspicuous because of their unusual size were 
located. Near the first house on the west side of the road north 
of the Tully limestone ledge, which is crossed by the highway 
leading northward from Moravia, is a granite bolder showing 
io| feet by 8 feet by 4 feet above the ground. On the farm of 
S. C. Gooding, about a mile east of Groton, is another very large 
bowlder. The largest bowlder found in the quadrangle may be 
seen on the steep western wall of Skaneateles Inlet valley in a 
wood lot belonging to E. Griffin; its location is a few rods south 
of the overflow channel (p. 432) which has incised this west wall. 
The size of the bowlder may be judged from fig. 20. 
Ice Dammed Lakes. 
Some of the high level lakes of this quadrangle have been studied 
by Fairchild and by Watson. Their study has been particularly 
along the line of correlating deltas and locating overflow channels. 
They mention old deltas at Moravia and in the vicinity of Locke. 
Plate XII refers by letters and dotted outlines to the several 
high-level deltas of the sheet. I will discuss these deltas in the 
order in which they are designated. 
^A ’’ village of McLean is built mostly on a delta (fig. 
21) the altitude of which is about 1120 feet. The southern seg- 
ment shows the best development, as northward these gravels 
have suffered m.uch from post-Wisconsin stream work. The lake 
in which this delta was accumulated evidently was of short dura- 
tion. It is remiembered that southwest of this area, towards 
Mallory ville, the valley is completely blocked with kame moraine; 
