594 HERMAN L, FAIRCHILD 
due to contributory deposition by ice, especially as they are 
quite stony. 
The ice-block was probably not entirely buried but projected 
above the surface of the delta, otherwise the deep swamp kettle 
would have been partially filled with the water-laid delta material 
falling in upon the melting ice. The notch at the edge of the 
kettle is apparently a constructional form, and there is no 
evidence of any current of water having flowed through it. It 
is still a narrow ridge, although somewhat flattened or lowered 
by use for a roadway leading into the basin. The water from 
the dissolving ice-block probably filtered out through the sur- 
rounding gravel. 
A natural objection to the ice-block theory is the existence 
of such an isolated mass of ice for a great length of time. The 
relations of the stream and delta with the water bodies require 
the ice-front to be removed some uncertain distance to the 
northward. This objection, however, has not been given great 
weight by the students of similar phenomena. 
This basin is by far the largest one that the writer has seen 
in the lacustrine deposits of western-central New York. How- 
ever, it is not the only one suggesting ice-block genesis. Other 
deep steep-sided kettles have been seen in the deltas, especially 
on the slopes of Seneca and Keuka valleys, which may most 
reasonably be attributed to such origin. The writer has partic- 
ularly in mind one a short distance above the Hector station, on 
the east side of Seneca Lake. This seems to lie above the 
plane of glacial waters and was apparently formed in the 
exposed delta. 
In many deltas, small basins, or hollows, or bowls, occur 
which have been attributed to aqueous forces alone. These are 
usually located behind embankments or bars lying transverse to 
the stream, and vary in form from hollows open at one end to 
wellenclosed kettles. So far as noted, although close study has 
not been made, the walls are of clear sand or gravel, the depths 
not great as compared with the breadth, and the forms are simple 
curves. Their origin seems explained by conflict of waves and 
