550 hawkes. GEOCHEMICAL PROSPECTING FOR ORES [Ch. 30 



speaking, the aspects of geochemical prospecting that need further re- 

 search may be listed as follows: 



Analytical procedures. New or improved tests are needed for many 

 important elements, such as lead, cobalt, molybdenum, vanadium, ar- 

 senic, antimony, silver, and gold. 



Geochemical principles. A better understanding is needed of the 

 chemical and biological factors that affect the mobility of ore metals 

 in the cycle or weathering. 



Field applications. Many more experimental studies of the disper- 

 sion patterns of ore metals emanating from known deposits are neces- 

 sary before the general applicability of geochemical methods to pros- 

 pecting can be evaluated. 



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