232 



Till'. NATIONAL CKOCR AIMIIC M AT.AXI X K 



Photograph by L. G. Folsom 



KOLB IN THE ROLE OE SAMSON 



Balancing such a "rock" in the air is not so much of a feat as it appears, for the mass 

 is a chunk of pumice blown so full of bubbles by the gases of the eruption that it might 

 float on water. Such large pieces of pumice are confined to the vicinity of Novarupta. 

 All the ejecta of Mount Katmai itself are very finely divided because of the greater violence 

 of its explosion. 



than the solid rock of a hardened lava 

 flow (see page 225). 



valley surrounded by "iiigh-sand 

 mark" oe the fiery torrent 



One of the most conspicuous features 

 of the valley as it stands today is the 

 clear-cut margin of this great mass of 

 once incandescent sand, which stretches 

 in a practically continuous high-water 

 mark all around its margin. The con- 



tinuity of this "high-sand mark" shows 

 clearly that the incandescent mass was 

 not poured down one of the adjacent 

 mountain sides into the valley, but must 

 have originated from vents within its 

 confines. This is clearly evidenced by 

 many additional facts which cannot be 

 detailed here (see page 220). 



During the whole period of flow the 

 mass was probably kept in a state of con- 

 stant turmoil by the continued evolution 



