CHAPTER X. 



GLACIAL EROSION AND TRANSPORTATION. 



The extent of glacial erosion is a hotly contested question. 

 One class of writers has gone to the extreme of attributing 

 almost all the erosion of the higher latitudes to glacial action, 



Fig. 70.— Canon of the Colorado. Stream-erosion in a dry climate. (Newberry.) 



while another class has scarcely allowed any eroding power 

 to glacial ice, in comparison with that of running water. 

 In considering the relative importance of these agencies. 



