OF DENISON UNIVERSITY. 23 



valley just north of Piketon and opposite Waverly. (4) And from 

 Dr. Edward Orton's description in the Ohio Geological Survey, Vol. 

 II, p. 611 that there was an ancient drainage feature in southeastern 

 Pike County. 



In the spring of 1896 Mr. Frank Leverett, of the United States 

 Geological Survey, while engaged in field work in Ohio, called on me 

 and I gave him the results of my work. I also stated to him at that 

 time that it was my opinion, if as I suspected a continuous valley should 

 be found to extend from Sciotoville northward past California Flats to 

 the Scioto valley at Waverly, it must be connected with the " Flat 

 Woods and Teazes Valley drainage and substantiate more fully the gen- 

 eral drainage line indicated in my former article in this series. Vol. 

 VIII, Part II, Plate V. 



He at once planned to visit the region and after about two weeks 

 in the field Mr. Leverett returned and reported that he had found it 

 as expected and had traced the valley all the way from Wheelersburg 

 to Waverly. Some months later it was possible for me to visit the re- 

 gion also and the data given in this article and shown in the plates and 

 map were obtained during my visit. As the credit of first establishing 

 this old valley belongs to Mr. Leverett I asked him to contribute to 

 this series his interpretation of the region. He has complied and arti- 

 cle HI of this series and volume is from his hand. Whatever similar- 

 ity the reader may find in the substance of these two articles or the 

 plates presented with each should be taken as increased evidence of 

 the truthfulness of the observations and conclusions as the two are of 

 independent origin, except so far as stated above. 



2. SOME FEATURES OF THE OHIO RIVER VALLEY. 



The great trough of the Ohio river presents many problems of in- 

 terest to the geologist and within a few years some new and startling 

 theories have been advanced with reference to certain cycles of its de- 

 velopment history. The truth or falseness of these theories remains to 

 be proven by the accumulation of evidence for or against them. 



In a former part of this series Vol. VIII, Part II, page 60, the 

 writer expresses the belief that the Ohio river valley, in the portion 

 along southern Ohio, is made up of modified parts of other preglacial 

 drainage systems and its present position largely determined by the 

 position of the lowest cols between the various elements. 



