1/2 Bulletin of Laboratories of Denison University [Voi. xi 
ing northwest past Glenford, emptied into the old preglacial 
Muskingum valley near the Licking reservoir.^ 
The other stream on the east side of the divide flowed 
east past the Moxahala gorge through the now buried channel 
of the Moxahala river and emptied into the preglacial north- 
flowing Muskingum at Zanesville. 
When the ice sheet invaded Ohio, covering the central and 
western parts of the State, that portion of Jonathan creek flow- 
ing from the western side of the divide was filled with glacial 
waters. Its current was reversed and the great volume of water 
poured down from the tongue of ice extending into the valley, 
ponded up against the divide. At the point indicated by the 
col on the map, the glacial waters cut through the divide, unit- 
ing the two drainage systems into one present, continus system. 
The geological structure of the divide amply allows for the con- 
sideration of such a theory. The narrowness of the valley im- 
mediately to the east of the col, the silting up of the valley 
from the col west to Glenford, the furrowed out character of 
the valley east of the col all lead to such a conclusion. 
Attention should be called to the form of the section o^ 
the valley east of the gorge. At the top it has the appearance 
of the old preglacial valleys : broad, with sloping sides. The 
lower portion, however, is deeply furrowed out, evidently the 
result of recent water action. Before the torrents of glacial 
waters poured over the divide, the stream then occupying this 
portion of the valley, coursed through a broad open valley. 
The volume of water which came down from the ice field, load- 
ed with eroded material, cut down the old valley to a great 
depth, leaving it in its present form. 
The preglacial channel of the Moxahala river from where 
it leaps through the divide, between the south fork of Jonathan 
creek and the Muskingum river to Zanesville, has a depth of 
filling of 50 feet above the flood plain of the Moxahala. 
When the rivers of glacial waters forced the north-flowing 
preglacial Muskingum to change its direction of flow, the coun- 
1 Bulletin Vol. VIII, Ft. 2, 
