APPLIED GEOLOGY. 



By Alfred H. Brooks. 



The science of geology, generally regarded as having originated 

 in the vague speculations of the cosmogonists hardly two centuries 

 ago, has to-day become of great practical utility. During the 

 past decade all geologic investigations have shown a marked ten- 

 dency toward material problems, which is in contrast with the 

 previous decade, w^hen the interests of pure science were much 

 more strongly emphasized. No one will deny that economic or, 

 as I prefer to call it, applied geology is attracting more and more 

 attention from professional geologists. It is appropriate that the 

 members of this society should take cognizance of this trend in 

 geologic thought, analyze the conditions which have brought it 

 about, and decide, it may be, whether it makes for the good or the 

 evil of the science. 



Before discussing this subject it will be well to attempt a defini- 

 tion of the term "appHed geology." Some appear to believe that 

 when the geologist emerges from the tunnel's mouth he is at once 

 transplanted into the realm of pure science, and that the miner's 

 candle illuminates only the so-called practical, or even commercial, 

 problems. I submit that such opinions are not justified. The 

 surveys made as a basis for geologic maps and structure sections, 

 usually classed as belonging to the realm of pure science, often 

 yield results which are the most concrete examples of appHed geology. 

 On the other hand, the exhaustive study of mmeral deposits is essen- 

 tial to the solution of many fundamental geologic problems. A 

 close analysis wUl make it evident that the line of demarcation 

 between the fields of pure and applied geology is, in a large measure, 

 arbitrary. The collection to-day of a new group of facts or the 

 determination of new principles relating to pure science may result 

 to-morrow in thcii* application to industrial problems. ^Ir. Gilbert 

 has recognized two fields of geologic research, the one embracing 

 the study of local problems of stratigraphy, structure, etc., the 



I Presidential address delivered before the Geological Society of Washington, Doc. 13, 1911. Reprinted 

 by permLssion, with author's corrections, from Journal of the Washington Academy of Science, vol. 2, 

 No. 2, Jan. 19, 1912, pp. 19-4S. 



* Published by permission of the Director of the United States Geological Survey. 



329 



