CHAPTER XXVIII 



GEOLOGICAL FORCES AT WORK 



IT seems to me that never before have I seen the 

 geological forces of nature so obviously at work. 

 Elsewhere I have seen great valleys, cliffs, islands, etc., 

 held on good evidence to be the results of such and 

 such powers formerly very active; but here on the 

 Athabaska I saw daily ev- 

 idence of these powers in 

 full blast, ripping, tearing, 

 reconstructing, while we 

 looked on. 



All the way down the 

 river we saw the process 

 of undermining the bank, 

 tearing down the trees to 

 whirl them again on dis- 

 tant northern shores, thus 

 widening the river channel 

 until too wide for its normal flood, which in time 

 drops into a deeper restricted channel, in the wide 

 summer waste of gravel and sand. 



Ten thousand landslides take place every spring, 

 contributing their tons of mud to the millions that the 

 river is deporting to the broad catch basins called the 

 Athabaska and Great Slave Lakes. 



197 



Bank exposing different levels, etc. 



Showing how various floods and ice plowings have 

 changed the level within recent years 



