44 POPULAR SCIENCE MONTHLY 



remains geologically unmapped, there will be a hiatus in our knowledge, 

 which may prevent broad generalizations. 



In Alaska special attention has been given to the second field of 

 activity, namely, the application of geology to the needs of the miner. 

 This is in part the influence of the growth of economic work in both 

 state and federal surveys during the last decade, but more specially 

 because the appropriation is specifically made for the investigation of 

 the mineral resources of Alaska. With this end in view, a score of 

 publications dealing with the occurrence and distribution of the mineral 

 deposits of the territory have been issued. It has been the policy to 

 make public the results attained while yet the investigation is in prog- 

 ress, in the belief that even an incomplete knowledge of the geology 

 would be of value to the miner. With this end in view, bulletins treat- 

 ing of the occurrence of coal, petroleum, tin and copper have been 

 issued, as well as many which are devoted to the gold deposits. These 

 preliminary reports have found favor with the mining public because 

 of their timely appearance, and have forestalled criticism of delay in 

 issuing the more elaborate treatises. 



The danger in issuing such reports is that the less intelligent miner 

 may accept tentative statements as final conclusions, and this may lead 

 to losses. It is impossible to escape this danger entirely, for to avoid 

 all opinions which are not definitely established by the facts in hand, 

 shears a geologic report of much of its usefulness to the practical man, 

 who wants the expert who has visited the field to prophesy what the 

 conditions of occurrence of the ore bodies are likely to be. 



While applied geology has been kept constantly to the front in the 

 Alaskan investigations, the study of the broader problems, be they 

 stratigraphic, physiographic or paleontologic, has by no means been 

 lost sight of. The purpose of every geologist sent to the north has 

 been twofold: first, the gathering of information which will directly 

 advance the mining interests, and, secondly, the study of the purely 

 geologic problems. It has been the policy to defer the publication of 

 purely scientific results until a larger number of facts have been accu- 

 mulated, and the theoretic discussion can be supported by the knowl- 

 edge of a wider field. Thus only the salient outline of the stratigraphic 

 succession has been put in print, but meanwhile a number of specialists 

 have been carrying on paleontologic and stratigraphic studies to de- 

 termine definitely certain geologic horizons to which all future work 

 can be referred. In the same way, though a large petrographic collec- 

 tion has been amassed, its detailed study has been deferred until a 

 broader knowledge of the field relations can be secured. Other branches 

 of geologic science have been treated in a similar way. It is hoped that 

 in this way a basal knowledge of the larger problems will be available 

 in a few years, on which to found detailed studies with more assurance. 



