Conclusion. 
23 
In the case of the junction deposits it seems to this writer that 
a satisfactory explanation of their origin may be found by sup¬ 
posing that these deposits mark the points at which one or more 
crevasses in the ice intersected eskers. The radiating gravel 
ridges now mark the position of the intersecting crevasses. 
That all these gravel deposits were made near the ice front is 
probable from the fact that a little farther south all the gravel 
is spread out in sheets. It is therefore reasonable to suppose 
that there were openings in the ice-front, bay-like in character, 
and that there were other openings within the ice-border less 
directly connected with the open water along the ice border 
The suggestion is offered, therefore, that these variously dis¬ 
posed bodies of esker material mark the places where openings 
of greater or less size had been formed by various agencies not 
far from the ice-front and in the path of the ice rivers. The 
streams would pour their contents into these openings. The 
water would escape; but the sand and gravel would accumulate 
in the openings until it either filled them completely, or until 
new avenues were opened for its onward movement. At the 
final melting of the ice all these deposiis would be left resting 
on the till beneath, whether the streams which brought the ma¬ 
terial were sub-glacial or englacial. 
Madison , Wis. 
1 It is not meant here to assert that still water of any depth was to be 
found along the ice-front at the time mentioned, although such might 
have been the case. 
