LEAD AND SILVER. U5 



" Copper " (Example 20A), as it contains much copper. The ore is 

 thought by Hollister to have replaced the limestone. 1 



Passing mention should also be made that lead-silver ores occur 

 in Summit County, at the Crescent and other mines. 



2.08.26. Example 30g. Horn Silver Mine, Beaver County. 

 A great contact fissure between a rhyolite hanging wall and a 

 limestone footwall, and carrying, at the Horn Silver mine, oxi- 

 dized lead-silver ores, chiefly anglesite, with considerable barite, 

 and with many other rarer minerals. The town of Frisco, con- 

 taining the mine, is at the southern end of the Grampian Moun- 

 tains. The great fissure is known for two miles, but is proved 

 valuable only between the lines of the Horn Silver mine. It 

 strikes north and south and dips 70 east. In the neighborhood 

 of the vein the rhyolite is largely altered to residual clay. The 

 mine is very dry and the entire region lacks good water. The 

 vein in general varies from 20 to 60 feet, but has pinched twice in 

 going down, and of late years has largely ceased producing, al- 

 though there may yet be much ore below. The ores are smelted 

 near Salt Lake, and the base bullion is refined at Chicago. Some 

 free milling ore has been afforded. 2 



2.08.27. Example 33a. Carbonate Mine, Beaver County. A 

 fissure vein in hornblende andesite, filled with rounded fragments 

 of wall rock, which are cemented by residual clay and galena. 

 Some oxidized products occur near the surface. The mines are two 

 and a half miles northeast of Frisco, but are in a different eruptive 

 rock from that forming the walls of the Horn Silver. The literature 

 is the same as for Example 30</, especially Hooker, 1. c. p. 470. 



2.08.28. Example 32&. Cave Mine, Beaver County. Cham- 

 bers irregularly distributed in the limestone, and more or less 

 filled with limonite and oxidized lead-silver ores. Small leaders 

 of ores, which mark old conduits, connect the chambers. Up to 

 1880 five large and fifteen small chambers had been found. They 

 are of very irregular shape, and have a vacant space of from one 

 to ten feet between the ore and the roof. This deposit was the 

 typical one cited by Newberry as illustrating the chamber or cave 



1 D. B. Huntley, as above (footnote, p. 194) ; ab-o O. J. Hollister, as 

 above, under Example 35a. J. S. Newberry, Engineering and Mining 

 Journal, Sept. 13 and 20, 1879. 



2 O. J. Hollister, "Gold and Silver Mining in Utah," M. E., XVI. 3. 

 Eec. W. A. Hooker, Report quoted in the Tenth Census, Vol. XIII., p. 464. 



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