48 The American Geologist. July, 1895 
at the line of the Rochester moraine, the conditions were pe- 
culiarly favorable for dropping the detrital ice-burden rap- 
idly and in large amount. The areas immediately north and 
south of the Pinnacle hills are quite free from morainic accu- 
mulations, although covered by lake silts. The materials that 
under some conditions might have been scattered over a large 
area are here concentrated in a narrow belt. Three or four 
moderate streams at intervals of nearly one mile apart could 
have produced the Pinnacle hills in a comparatively short time. 
Perhaps such an interval was not too close for the drainage 
lines of this rapidly dissolving ice-front. 
Comparison with Neighboring Kame Areas. 
The Pinnacle hills are far from being the only kame-like 
deposits of the region, for over the relatively smooth plain of 
Monroe county several other accumulations of sand and gravel 
are conspicuous. At least two of these surpass the Pinnacle 
hills in amount of material. As these neighboring deposits 
have a bearing upon the subject under discussion they will be 
briefly described. 
(1). The Chili S((nd Jfills. — Six miles southwest of Roch- 
ester occur some curious hills and knolls composed chiefly of 
fine sand. These knolls are partly indicated in the map. 
They are twenty to forty feet high, lying upon a foundation 
of till. Among themselves they have no order, but have in- 
dividually an east and west elongation. They lie in a north- 
east by southwest belt about one mile wide chiefly between 
the New York Central railroad (main line) and the Chili 
wagon road and reach northeast to the moraine, which is 
there partly of the same character. Two drumlins lie in the 
eastern edge of the sand belt partly covered with the sand, 
and another may form the base of the larger group of sand 
knolls. The higher of the sand knolls have an altitude of over 
620 feet. Upon the highest summits are numerous granitoid 
boulders, evidently ice-rafted. These hills have been studied 
by Mr. Frank Leverett. They appear to have been formed by 
the drainage from the glacier, with deposition in lake Warren. 
The east and west elongation may be regarded as indicating 
a morainic origin. 
(2). The Lincoln Park Kame Area. — Close to the western 
border of the city and north of the moraine is another area of 
