June, 1920] 



The Great Mageik Landslide 



329 



almost free from debris, and forming a deep hollow all around its 

 base, in which has gathered a considerable body of clear green 

 water, the "Horseshoe Pond." (See pages 330 and 336). 



Even more significant than the absence of moraines along the 

 margin of this terrane is the fact that it branches. In addition 

 to the two main forks, there is, near the terminus, a manifest 

 tendency for the edges to splay out into minor branches. 

 Parts of two of these little branches are well shown on page 345. 

 A forking glacier is, to be sure, no impossibility; but a mass of 

 ice can be divided only when it meets an insuperable obstacle 

 capable of withstanding the enormous power of its advance. 



Photograph by Robert F. Griggs 



A THIN EDGE OF THE SLIDE. WHERE IT RAN UP THE SIDE OF A 



LITTLE HILLOCK. 



The grass land at the left was not touched by the slide. The covering of debris is 

 so thin that it scarcely alters the contour of the hill. 



In this case no such obstacle existed, for the terrane lies in a 

 broad open valley which happened to be occupied by two 

 streams flowing in separate courses to their confluence below. 



Originating on a branch at an angle to the general course of 

 the main valley, it ran straight across the valley and then, 

 turning the corner, continued for more than two miles down the 

 beds of the two streams. The height of the divide which thus 

 served to split it is so slight that it seems 



altogether 



mcon- 



