BAix.] SOURCES AND USP:S OF FLUORSPAR. 69 



silica, or spar mixed "vvitli calcite, can be used in foundry work, and 

 while the price is and always must be low. there is possible an almost 

 unlimited market. It is probable that systematic eiforts to introduce 

 the low-gi-ade material into this trade Avould be highly beneficial to 

 the industry as a whole. While there would l)e little profit in min- 

 ing foundry spar, it would allow the production of No. 2 spar in 

 quantity and at prices demanded by steel makers. With the exhaus- 

 tion of bessemer grades of ii-on there will l)e an increased demand 

 for fluorspar, though even now demand is ahead of supply for steel- 

 making grades. Since at any increase in prices it becomes cheaper 

 to use less efficient fluxes, it follows that while the output can be 

 increased prices probably can not be much changed. 



With these facts in mind it is seen that the fluorspar mines of the 

 Kentucky-Illinois district will have for many years a large and 

 growing market to supply. Their only competitors are the importers, 

 and competition with them is maiidy a matter of transportation costs. 

 It is not certain that this competition will always be keen as now, since 

 foreign producers have an important and growing trade outside 

 the United States. Mines in the Rocky Mountain region and other 

 Western States can not be expected to disturb the fluorspar market. 

 Such fluorspar as occurs in connection with the ores of that region 

 Avill probably always have a sufficient local market. The quantity 

 present is nf)t im})ortant in any western district yet described, and 

 local smelters make an allowance for lime, which, entirely aside from 

 the cost of transportation, is likeh^ to prevent shipments of spar to 

 the East. 



FlTTl RE PRODUCTION. 



The o])inion already given as to the genesis of the ores indicates 

 the belief of the author that they will prove permanent in depth to 

 horizons below which they can not be worked because of increasing 

 cost. The low value of the ore places a somewhat severe limitation 

 upon the future depth of mining, and it is possible that this feature 

 alone will in most situations preclude work to a depth greater than 

 1,000 feet. It is also possible that changes in the character of the 

 country rock may influence disastrously the size and character of the 

 ore bodies. It has been impossible to get any data on the character 

 of the rock which occurs in this area beneath the Ohio shale. Nor- 

 mally a considerable thickness of dolomites and limestones would be 

 expected to be present, but they may be absent, and it is not impos- 

 sible that the supposed igneous mass occurs below the shale. In all 

 the mines so far located in Illinois the shale lies 500 to 1,000 feet or 

 more below present workings. 



