82 



UNITED STATES MINERAL RESOURCES 



250 feet (most are much shallower) that contain 

 more than 125 pounds of recoverable barite per cubic 

 yard of residuum processed. This cutoff includes 

 material that is subeconomic by the 1972 standards 

 of about 220 pounds of barite per cubic yard of 

 residuum. An identified resource of 1.9 million tons 

 of barite is reported in 67 tailings ponds in the 

 Washington County barite district, Missouri (Whar- 

 ton, 1972, p. 55). 



Identified resources of vein material include ores 

 in a v^^ide variety of grades, with and without po- 

 tential coproducts in deposits within 1,500 feet of 

 the surface. The common coproducts are, or could 

 be, one or more of the following: fluorspar and 

 minerals of lead, zinc, silver, gold, and rare earths. 

 Some of these barite ores must be literally redis- 

 covered in known metal districts. In earlier times, 

 bodies of mixed ore, especially of barite and fluor- 

 spar, were bypassed in mining because it was then 

 impossible to beneficiate them economically. Tech- 

 niques for the beneficiation of these mixed ores are 

 now available. The estimates of resources also in- 

 clude some barite available by reprocessing mine 

 dumps and tailings ponds. Parts of settling ponds 

 at old washer plants in the Washington County 

 district, Missouri contain as much as 35 percent 

 fine-grained barite. 



Barite resources of Alaska have scarcely been 

 evaluated, but are of considerable interest because 

 of anticipated oil production on the Arctic slope. 

 Vein deposits were mined in 1972 on Castle Island 

 in the Petersburg region, and vein deposits in the 

 Skagway area have been recently described by Mac- 

 Kevett (1971). A potential ore target for barite, 

 fluorite, and metal sulfides has been identified near 

 Nome on the Seward Peninsula (Brobst and others, 

 1971). In northern Alaska, gray barite occurs in 

 cherty rocks of Paleozoic age (Tailleur, 1970), and 

 abundant barium occurs in shales of Mesozoic age 

 that are rich in organic matter (Tourtelot and Tail- 

 leur, 1965). The distribution of the occurrences sug- 

 gests that the Brooks Range might also contain 

 barite deposits of commercial value. 



Hypothetical resources listed in table 13 were esti- 

 mated for each type of deposit using the same limit- 

 ing depth as for the identified resources; however, 

 the cutofi' for bedded deposits is reduced to 30 per- 

 cent barite and for residual deposits to 75 pounds of 

 recoverable barite per cubic yard of residuum proc- 

 essed. The grade of vein deposits included in this 

 estimate varies as widely as in identified resources, 

 but a favorable potential for coproducts is regarded 

 as economically necessary for exploitation. 



A summary of the world's identified and hypo- 



thetical resources of barite is shown by continent 

 in table 14. The identified resources are extrapolated 



Table 14. — World resources of barite in millions of metric 

 tons 



Hypothe- Specula- 

 Area Identified ' tical ^ tive ^ 



North America 118 180 400 



Central America and 



the West Indies 2 5 10 



South America 15 20 100 



Europe 75 85 220 



Africa 38 50 200 



Asia 52 50 300 



Oceania 10 10 50 



Totals 310 400 1,280 



^ Identified resources: Specific, identified mineral deposits that may or 

 may not be evaluated as to extent and grade, and whose contained min- 

 erals may or may not be profitably recoverable with existing technology 

 and economic conditions. 



- Hypothetical resources: Undiscovered mineral deposits, whether of re- 

 coverable or subeconomic grade, that are geologically predictable as 

 existing in known districts. 



^ Speculative resources: Undiscovered mineral deposits, whether of re- 

 coverable or subeconomic grade, that may exist in unknown districts or 

 in unrecognized or unconventional form. 



from world reserve data described and tabulated by 

 Brobst (1970). Outside the United States, perhaps 

 as much as 75 percent of the identified barite re- 

 sources are in vein deposits, many of which are 

 mined or are minable for multiproducts. The hypo- 

 thetical resources are predicated on estimates for 

 similar types of deposits in the United States. 



Barium-rich nodules have been found on great 

 areas of the sea floor. The barite might eventually 

 be recovered as a coproduct with other materials, 

 notably manganese, although much remains to be 

 done on the recovery and processing techniques. The 

 resources probably are large, but they are as yet 

 mostly unmeasured, and none are included in the 

 total for identified resources of conventional de- 

 posits. 



Barite is associated with carbonatite in east 

 Africa and probably elsewhere in the world, but the 

 commercial potential of these deposits remains to 

 be evaluated fully. 



In northern Honshu, Japan, layered volcanic rocks 

 of Miocene age contain black ore (kuroko) consist- 

 ing of economically recoverable amounts of pyrite, 

 barite, copper, lead, zinc, silver, and gold. The 

 geology and beneficiation of these ores have been 

 described recently (Mining Engineering, 1969). 

 Deposits similar to these also might occur in the 

 Western United States and other countries in the 

 circumpacific volcanic belt. Deposits of this type 

 probably have not been sought in many places where 

 potential for their discovery is good. 



SPECULATIVE RESOURCES 



The speculative resources, those of undiscovered 

 districts, are large. 



It is highly probable that additional deposits of 

 black bedded barite will be found in dark siliceous 



