15! 



BiiUelin of Laborato7-ies of Denison Unh'ersitv. Vol. xill 



FUj. 2. View loiikin.;;- across the Old X'alley luwni-d Ibe east. Note the con- 

 tinuous upward shjpe of the east wall, almost conceaiini; Siiiinir Valley l.vinjr 

 l)etween X-X. The mature appearance of the Old Valley, witli the cut of the 

 central drainage line throuiih imconsnlidated material is shown. 



may be also ui'.^'ed at^ainst aii}' theory of intcr-oiacial origin. 



The present drainage hnes of the Old X'ahey, with the excep- 

 tion of Spring Valley, offer little of interest following as they do 

 subsequent courses over the drift. 



In connection with this discussion of the ( )ld N'alley, it luay 

 be mentioned that there is evidence of a west-tlowing pre-glacial 

 stream in the valley of the Raccoon (to which this Old \'alley is 

 tributary). The cause for the diversion of Raccoon Creek at this 

 point from a west-flowing to an east-flowing stream will be the 

 subject of a future paper. 



SPRING VAI.LEY STREAM." 



Spring Valley Stream is formed by the union of two slight 

 creeks, converging and draining the entire southerly portion of the 

 Old A'allev. These two streamlets, starting on the valley walls, 

 follow lines through the drift, and i)resent no peculiar drainage 

 features until a short distance be}-ond their jimction (J. Fig. 1). 

 where a sharp bend eastward then a northward turn leads the 

 united stream through a gorge cut into the eastern wall of the 

 Old X'alley. This portion of its course is known as Si)ring \'alley. 

 l>(>th data and theory will be given to show that Spring \ alley 



" See reference under the Old Valley. 



