Drainage Changes in the Moot^s Run Area 227 
along the second tributary, we find that it cuts directly across the 
southwest wall of the preglacial valley, exposing rock almost to 
the top of the channel. Rock walls, for the most part, confine 
this tributary throughout its course to a point a short distance 
west of the highway north of the Lewis School, then suddenly 
give place on both sides to glacial drift. Here we have a repetition 
of the same phenomenon observed at Moot’s Run, i.e., a narrow 
rock gorge succeeding a wide valley confined between walls of 
glacial drift. This stream in its westward portion lies on the 
^^blue clay,” which may represent an older ice invasion than the 
yellow drift composing the terraces above. This relationship 
suggests another buried channel. 
Returning to Moot’s Run, and tracing its course westward 
from the point where the rock bed gives place to drift, a short 
distance west of the ^Hend,” we find that both walls are composed 
chiefly of drift for almost all the way; the valley walls are fairly 
high, and have the gentle slope which drift always takes. There 
is an occasional outcrop of rock in the bed of the stream, one in 
particular being noted near the house of T. Carroll, where the 
rock is at least 50 feet higher than at Parker’s. This is probably 
due to the fact that the last records are from wells sunk into the 
descending rock slope of the old channel, which cut tangentially 
across the headwaters of the second tributary a little to the 
southeast of this point. 
Resume of glacial movements over the area. The first glacial 
invasion of this region, according to present knowledge, was the 
Illinoian, which probably reached as far south as Cincinnati, 
Ohio. At its farthest extent the ice front lay across Licking 
County in a northeast and southwest direction; we infer this 
from the fact that the southeast portion of the county is driftless. 
A very large portion of Licking County is the modified topography 
of a terminal moraine. The Illinoian drift is probably repre- 
sented by the old ^^blue clay,” a metamorphosed glacial deposit, 
and the Wisconsin is represented by the so-called yellow clay.” 
These ice sheets, making their final stand, deposited very 
heavy blankets of drift, which masked the minor drainage lines 
of this area. Observations on the thickness of this drift in the 
Alexandrian area are given by Scheffel in the paper cited above. 
It is probable that in our area the heavy drift deposits of the ter- 
Carney, loc cit. 
