Clarence King — Geologist 



knowledge of the different varieties of 

 volcanic rocks, acquired during field 

 studies around the extinct volcanoes 

 of the northern Sierras and in associ- 

 ation with his friend Baron von Richt- 

 hofen, and in which for many years 

 he stood pre-eminent among geolo- 

 gists of his time. 



King's earliest scientific achieve- 

 ment on the Survey was the discov- 

 ery, during the study of the gold 

 mines of the Mariposa estate in 1863, 

 of fossils in the highly metamor- 

 phosed slates of the gold belt of Cali- 

 fornia, a discovery that solved the 

 problem of their age which had long 

 puzzled Western geologists. 



In the autumn of 1866, after his 

 return to the east, he judged that 

 political conditions were then most 

 favorable for the realization of a plan 

 that had gradually been shaping itself 

 in his mind ever since he first crossed 

 the continent, viz.: that of connecting 

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