OF DENISON UNIVERSITY. 6 1 



age of what I have termed the Tertiary Ohio river was deflected 

 to the east and the St. Lawrence system developed. 



We can not close without noting the relation of the restored 

 drainage of Ohio to the underlying rock structure. It becomes 

 very apparent that the present correspondence between the drain- 

 age lines of Ohio and the strike of the strata is not related as 

 cause and effect. Such impressions have been gained by a 

 study of the geological map but the field observations do not 

 sustain such an opinion. A glance at Plate V will show that 

 the preglacial drainage is almost directly across the strike line. 

 In fact if we do not consider this restored drainage the position of 

 the present Ohio river is evidently across the strike and the case 

 already noted of the Scioto passing from the Ohio shales into 

 the Waverly at ChilHcothe makes us believe that monoclinal val- 

 leys are foreign to this region and that differential movements 

 have determined the great drainage systems which have subse- 

 quently been modified by glacial action. 



The present condition of our investigations leaves many 

 questions to be answered for which further field work must 

 be done. This article is only offered as a beginning in the 

 work. 



