THE 



AMERICAN JOURNAL OF SCIENCE 



[FOURTH SERIES.] 



Art. XXIII. — Criteria relating to Massive-Solid Volcanic 

 Eruptions ; by Israel C. Russell. 



Since Monte Pele presented geologists with a marvelous 

 illustration of the ability of a volcano under certain special 

 conditions to force a mighty column of solid lava vertically 

 upward into the air from the summit of its conduit, the 

 question has frequently been asked : Are other examples of a 

 similar nature known ? The reply is that no similar shaft of 

 solid rock has been seen to ascend from the summit of a vol- 

 cano, but evidences of former protrusions of a like nature 

 have been recognized, and as it seems, when search is made 

 aided by the experience recently gained on Martinique,* the 

 records of massive-solid eruptions that have occurred in the 

 past will perhaps be found to be somewhat common. 



In order that the appearance of the example of a massive- 

 solid volcanic eruption which will no doubt in the future be 

 taken as the type of its class, may be fresh in mind, the reader 

 should turn to the admirable photographs of the " obelisk " of 

 Monte Pele, published by Dr. E. O. Hovey, in this Journal, 

 October, 1903. 



The striking object lesson furnished by the growth of the 

 obelisk of Pele has already stimulated geologists to search 

 for the records of similar occurrences in other regions. 

 Results in this direction have been reported by Hovey,f who 

 during a continuation of his important explorations in the 

 Lesser Antilles, found that the Grand Soufriere of Gaude- 

 loupe, and the prominent central peak on the Island of Saba, 



* Descriptions and illustrations of the obelisk of Pele by E. 0. Hovey, 

 have been published in this Journal, October, 1903, vol. xvi, pp. 269-281 ; 

 and in Science for November 13, 1903, vol. xviii, pp. 633-634. These articles 

 contain references to the publications of other observers. See, also, " The 

 Pele Obelisk," by Israel C. Russell, in Science for December 18, 1903, vol. 

 xviii, pp. 792-795. 



f This Journal, vol. xvi, October, 1903, p. 281. 



Am. Jour. Scl— Fourth Series, Vol. XYII, No. 100.— April, 1904, 

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