44 THE U. S. GEOLOGICAL SURVEY 



and all minerals possessing radio-active and radio-responsive 

 products. More recently a systematic search has been made 

 for new deposits of petroleum, phosphates, nitrates, potash, 

 pyrites, and manganese. 



For the proper conduct of exploratory researches of this 

 kind, and indeed for the most effective collection of data rela- 

 tive to mineral deposits in the course of general geologic sur- 

 veys, it is essential that the geologists conducting the opera- 

 tions be thoroughly versed in the technology of the production 

 of the mineral sought. 



Recognizing that the ability to form a correct judgment as 

 to the practical utilization and value of an ore or other mineral 

 deposit in the ground is most effectively acquired through the 

 field observation of operating works and processes for the ex- 

 ploitation and reduction of the same or similar deposits, the 

 Survey regards it of the highest importance that the geologists 

 who may be called upon to appraise undeveloped mineral 

 resources in the public domain or in other regions of the coun- 

 try shall keep as closely as practicable in touch with the min- 

 eral industry, and shall have a knowledge of the factors con- 

 ditioning the successful treatment and utilization of the ores 

 he is examining. 3 



The methods employed in searching for new deposits are 

 not unlike those followed by private prospectors possessed of 

 adequate funds and acting under the advice of trained geolo- 

 gists. If possible, cooperative arrangements are made with 

 private parties who may be drilling in the areas selected for 

 exploration or in adjacent areas by which the cores removed 

 by their drills are turned over to the Survey for examination 

 and report. This method has been employed most consistently 

 in connection with the search for potash deposits which the 

 Survey has been making for several years. Describing this 

 cooperation, the report of the Director for 191 5 states : 4 



3 Report of the Director of the Geological Survey, 1915, p. 47. 

 'P. 44- 



