June, 1920] 



The Great Maoeik Landslide 



341 



The first time I ever observed such topography was on the 

 lower slopes of Augustine Volcano in Cook Inlet in 1913. 

 They were so striking as instantly to arouse speculation as to 

 their origin. (See cut below). At first I supposed they must 

 be some sort of an expression of volcanic forces. But a httle 

 examination made such a hypothesis untenable, because of the 

 heterogenous character of the debris of which they were com- 

 posed, and because of the clear evidence that they never 

 possessed craters nor any semblance of a radial structure. 



Photograph by Robert F. Griggs 



CONICAL PILES OF DETRITUS ON THE FLANK OF 



AUGUSTINE VOLCANO. 



The similarity to the topography of the Mageik Slide, and of the slide from Noisy 



Moiintain, illustrated on page 338, is obvious. 



SIMILAR CONES DESCRIBED IN OTHER SLIDES. 



In their discussion of the slide at Frank, Alberta, Mc- 

 Connell and Brock* say, "Peculiar conical mounds built of 

 loose rocks up to three feet in diameter were noticed at several 

 points. The origin of these mounds is uncertain, but some of 

 them may represent portions of ridges which have been partly 

 destroyed by flying rocks." These are clearly distinguished 

 from other cones which they thus describe : ' ' Diminutive 

 cones with crater-like depressions in the center, due to the; 



•■McConnell, R. G., and Brock, R. W. op. cit. 



