W. R. Jillson — Recent Volcanic Erujption. 



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of the flora of Mt. St. Helens, and from its limited erosion, 

 that it is a mountain of very recent volcanic origin." And a 

 little further on, speaking of the tree casts, he says, " Though I 

 was unable to visit the places where these tree moulds occur, I 

 talked with . . . men who had seen these casts, but none of 

 them had seen charred bark or wood in the holes." His con- 



FlG. 1. 



Fig. 1. Base view of lava block. Shows the strongly carbon- casted sur- 

 face of the lava where it found contact with the previously charred log. 

 The lava is distinctly vesicular. 



elusions are, however, that these casts are the source of the 

 peculiarly charred logs of the Kalama. Diller agrees with 

 Coville, and says these charcoal trees are probably at least 100 

 years old, and, '' If this be true it is probable that some of the 

 charred logs are not the result of the last eruption of Mt. St. 

 Helens, but an earlier one." This statement virtually amounts 

 to a recognition bj' Diller of volcanic activity on Mt. St. 

 Helens within the last century. 



