1 60 11a nsman — Glacial Modification of Drainage 



a depth, at one point, of over 100 feet and in drift 

 throughout its entire length, without reaching bed rock in 

 the stream bottom. Our explanation for the presence of 

 rock in the West Sixmile gorge and its absence in the 

 Moss Creek Ravine is given in fig. 5. 



Spring Creek (K, fig. 2) has likewise carved out a post- 

 glacial ravine in the eastern side of Rowe Hill, in some 

 places from 40 to 50 feet in depth, without revealing the 



Fig. 6a. 





/S^ 



n 





-'^-"i-^--'- 



H 





£T-_^J?_ 



'^*'*2Sf** 







J^^^^-^Zfi^- 



~-^F^ r -->Z 



~Z^--£^~- 



—— — — 





/ 



-,, .'_■ .,_;.- 



>:r :.-.\~: ^\ 



/ - r ' 



C" ; : -/'•':. '■:'::*-! 



'f=-^rt^Z^Zs 



~~-~— ~^~ — ~ ~ j—~ — ~ 





Fig. 6a. Cross section through the gorge of East Sixmile, at H (fig. 2), 

 to show how the gorge at this point has been intrenched into the western 

 rock slope of Davies Hill (M). 



bed rock of the hill, nor does the hill itself exhibit traces 

 of its central rock core except in one obscure outcrop 

 near the marginal channel at S (fig. 2). 



The evidence, therefore, of the gorge of West Sixmile ; 

 the ravines of Moss and Spring Creeks ; and the nature 

 of the material exposed on and in Spring Hill all lead to 

 the conclusion that Spring Hill is composed of a small 

 central rock core deeply mantled over with glacial drift, 

 especially towards the east in the region about and south 

 from Spring Creek. The relation of the thin and thick 

 drift is shown in fig. 3. 



IV. THE EVIDENCE OF EAST SIXMILE CREEK AND ITS 

 TRIBUTARIES. 



An extension of the same terminal moraine that has 

 diverted West Sixmile Creek from the lower portion of 



