58 BULLETIN OF THE LABORATORIES 



cial as is shown by the work of Prof. J, F. James, but it does not 

 present characters different from many other portions of the Ohio 

 gorge. Again it is evident from a study of the great uphfted 

 Tertiary peneplane that its general slope is to the northwest and 

 that it extends beyond the present position of the Ohio river. 

 To put it in another way the Ohio river has cut out its channel 

 across this side hill. 



15. Conclusions and Theoretical Considerations. 



In conclusion the following suggestions are offered as ex- 

 pressing the probable condition of the preglacial drainage of the 

 upper eastern portion of the Mississippi basin. The attempt 

 has been made on Plate V to partially represent by the red lines 

 the facts as worked out for the central Ohio region and the 

 course of the preglacial Muskingum. The upper Ohio basin is 

 also shown as given by Profs. Chamberlin and Leverett. The 

 question marks indicate doubtful and unexamined regions and 

 mere suggestions are there offered. An exact register is not 

 attempted but only the principal drainage lines are indicated. 



If the considerations of L. G. Westgate^ are correct, that 

 the post-carboniferous drainage developed an axis, as he thinks, 

 in the direction of the present Ohio between the up- 

 lifted area and the northern crystallines which was retained 

 throughout the Cretaceous and Tertiary cycles, that axis of drain- 

 age must be looked for along the line of the axis of Lake Erie 

 and the deeply buried Maumee channel. The upper drainage 

 of the present Ohio basin was to the north into this Tertiary 

 Ohio river as described by Profs. Chamberlin and Leverett. An- 

 other line of drainage was represented by the Tuscarawas — 

 Muskingum through its preglacial channel past Newark bending 

 slightly to the south below Columbus then to the north in the 

 vicinity of London and Urbana, east of Sidney, then west into 

 Indiana to join the main axis which was flowing south west into 

 the Mississippi. 



^American Geologist. Vol. XI, Page 245. 



