48 BULLETIN OF THE LABORATORIES 



whole succession of events accompanying the first advance and 

 final recession of the ice sheet of the Quaternary must be taken 

 into the account ; not only the general and widespread results 

 of glacial action but also the local and minor effects produced 

 along the margin and under local portions of the ice lobes. As 

 this region is just on the border line between the glaciated and 

 drift covered portion of the state and the nonglaciated area it 

 would be expected that the minutest detail of glacial action 

 would here be preserved and presented to the best advantage. 

 As it is not intended in this paper to discuss the question as to 

 the particular time in the glacial period when these changes took 

 place no attempt is made to distinguish between the first and 

 second invasion of the ice sheet or to correlate in any way the 

 relations of the drift deposits but only to show the effects of these 

 deposits and the ice sheet itself in modifying the drainage lines. 

 As our investigations began with the study of the Licking Nar- 

 rows we will first offer an explanation for that particular 

 region. 



During the maximum period of ice invasion the east- 

 ern border of that sheet which covered central and western 

 Ohio presented a front running north and south through Knox, 

 Licking and Perry Counties nearly coincident with the heavy 

 dotted line on Plate III which represents the line of hills bor- 

 dering the interior drainage basin. This same range of hills is 

 shown along the North and South Forks of the Licking at the 

 left hand margin of Plate IV. It is evident that when the ice 

 occupied this position it formed a very effectual dam across the 

 preglacial Muskingum valley at Newark. There were two 

 streams draining into this valley from the south, one along the 

 lower course of the Licking below Nashport which emptied into 

 the Muskingum through the gap now occupied by the canal. 

 The other, probably a much larger stream and one which reached 

 farther to the south entered at Dresden. 



When the valley was dammed up at Newark the waters of 

 the Muskingum, which was greatly increased in size by addi- 



