48 



ciimstances of extrusion rather than in the character of the ejecta. 

 Whereas the incandescent avalanches of tlie West Indian volcanoes 

 issned from old vents of the central type, observations such as have 

 been detailed in the case of Katmai exclude as possible source all of 

 the five old volcanoes adjacent to the Valley of Ten Thousand Smokes. 



A section of the sand flow close to the terminus. 



Photo by L. G. Folsom. 



The tree, about 30 cm. in diameter, was entirely reduced to 

 charcoal. The material was much less fluid than the lahar of 

 Klut, for it did not run out into a thin sheet as there, but 

 remained relatively massive close to the extremity. (The sand 

 is covered by stratified ash from Katmai and by outwash of 

 the stream which later cut the section). 



