XV. THE ROCKS OF MOUNT RAINIER 

 BY GEORGE OTIS SMITH 



DIRECTOR GEORGE OTIS SMITH of the United States Geological 

 Survey was born at Hodgdon, Maine, on February 22, 1871. 

 He graduated from Colby College in 1893 and obtained his 

 Doctor of Philosophy degree from Johns Hopkins University 

 in 1896. He had begun his geological work in 1893 and from 

 1896 to 1907 he was assistant geologist and geologist of the 

 United States Geological Survey. Since 1907 he has been 

 director of that important branch of the Government work. 



He had been studying the rocks of Mount Rainier before he joined 

 Professor Russell in the explorations of 1896. The record of 

 those studies was published at the same time as Professor 

 Russell's report in the Eighteenth Annual Report of the 

 United States Geological Survey for 1896-1897. With his 

 permission the record is here reproduced in full. So far as is 

 known to the present editor it is the most complete study yet 

 published on the rocks of Mount Rainier. 



The earliest geological observations on the struc- 

 ture of Mount Rainier were made in 1870 by S. F. 

 Emmons, of the Geological Exploration of the Fortieth 

 Parallel. The rock specimens collected at this time 

 were studied later by Messrs. Hague and Iddings, of 

 the United States Geological Survey. 1 This petro- 

 graphical study showed that "Mount Rainier is formed 

 almost wholly of hypersthene andesite, with different 

 conditions of groundmass and accompanied by horn- 

 blende and olivine in places." The only other petro- 

 S-aphical study of these volcanics is that of Mr. K. 

 ebbeke, of Munich, 2 upon a small collection made 

 on Mount Rainier by Professor Zittel in 1883. 



On the reconnaissance trips on the northern and 



1 Am. Jour. Sci., 3d series, Vol. XXVI, 1883, pp. 222-235. 



2 Neues Jahrbuch fur Min., etc., Vol. I, 1885, pp. 222-226. 

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