132 
Frank Carney 
ment. Each of these four lines of evidence should be clear if the 
change in the drainage took place before the Illinoian glacial 
period. 
This diversion may indicate an axis of uplift which presumably 
trended northeast and southwest, and was located westward of 
this area. Such a differential tilt would stimulate all streams flow- 
ing southeast or in a southerly direction, and retard streams flow- 
ing to the northwest or in a northerly direction. In consequence 
of this resulting differential in the cutting power of the streams, 
the rivers heading south or southeast of this township, encroached 
upon the drainage north and west. In this manner the divide in 
the vicinity of Mary Ann Furnace was gradually lowered, resulting 
in the leading to the southeast of all the drainage that formerly 
flowed past Wilkins’ Corners to the southwest. These same fac- 
tors, if operating, would account also for the narrow course in 
Lost Run valley on the western border of the township (fig. 9); 
with the cutting down of this divide the drainage basin of the 
southeast flowing streams was considerably enlarged by the acces- 
sion of area northwest of the township. 
While these two cases are the most obvious of the drainage 
changes in this area, there are also minor variations of slight con- 
sequence. 
It is my opinion that these diversions took place before any ice 
came into the area, that is, that this differential tilt or warp and 
the resulting stream captures were pre-Illinoian.^ One reason for 
this opinion is that the narrow parts of these valleys, that is, where 
the lowered-divides were located, now bear outwash deposits indi- 
cating that the divides were low enough, before the ice withdrew 
from the region, to become partly aggraded; another reason is that 
if the ice invasion preceded the captures, all the reversed segments 
of the southwest and west flowing drainage, as above indicated, 
must have been ponded, the water rising to the height of a col 
which it in time lowered. We would expect to find about the 
margins of these former lakes shore phenomena including either 
constructed beaches, wave-cut cliffs, or deltas. I am unable to 
find any such evidence of former water bodies. Furthermore the 
lowered-divide segments of these valleys are flat-bottomed because 
^ On the assumption that the oldest drift in this region is Illinoian in age; this 
drift may be Kansan. 
