40 THE PREGLACIAL DRAINAGE OF OHIO. 



Lebanon where the course of the stream has been changed by 

 man and only a few hundred feet from where one of the deep 

 wells was sunk; and the other perhaps a half mile from the 

 point at which the valley unites with the Little Miami. This 

 tributary valley may be explained in two ways: (i) It may 

 have been occupied by two streams, one flowing into that part 

 of the ancestral Miami which flowed from Ft. Ancient to the 

 north, and the other to the southwest past Lebanon and thence 

 into the abandoned channel which constituted a part of the pre- 

 glacial course of Todd's Fork. These streams must have been so 

 situated that their headwaters tapped the divide at the same point, 

 thus producing the present continuous valley. (2) The other 

 method by which this valley may have been formed was by an 

 old stream flowing from the present Little Miami past Lebanon 

 and thence into the main valley farther south. To this theory 

 there are two objections: (1) The stream occupying the adja- 

 cent portion of the ancestral Miami flowed north. Under such 

 conditions it is difficult to understand how there could be such 

 a cross stream ; (2) the rock in the valley a half mile from the 

 Miami and above the level of the latter is also against this theory. 



Caesar's Creek, which unites with the Miami between 

 Oregonia and Waynesville, flows through a narrow valley in 

 its lower course, but two or three miles above its mouth the 

 valley is at least a half mile wide. The divide between this 

 stream and the Miami is everywhere of rock except opposite 

 Mt. Holly where it is very low and composed of drift. In fact 

 this divide is a part of the Wisconsin moraine which skirts the 

 east side of the valley at this place. The gorge-like char- 

 acter of Caeser's Creek near its mouth, the expansion of the 

 valley a few miles up stream, and the low divide composed of 

 drift leads to the conclusion that Caesar's Creek is part of the 

 reversed stream, which once united with the ancestral Miami 

 opposite Mt. Holly. This interpretation it may be added is in 

 harmony with the great width of the Miami at the latter point. 



Now the question — what became of that branch of the an- 

 cestral Miami which we have traced as far north as Spring Val- 

 ley? This question cannot be answered as definitely as we 

 might wish. But there seems to be only one course possible 



