Transactions . Cross-section of pipe-vein.—Front , galena. B, clay. and very much resemble the latter; but unlike the cave openings,they are usually entirely void of all gangue, being simply a deposit Fig. Cross-section of pipe-vein.—Side , galena, and clay. of block mineral. Mining in these two deposits is very precari-ous, as they are very rich for short distances, and then suddenly, SPELTER PRODUCTION. 125 without any warning, all traces of the ore disappear. I am ac-quainted with no successful mining in these two deposits. Besides the above, there are several other
Transactions . Cross-section of pipe-vein.—Front , galena. B, clay. and very much resemble the latter; but unlike the cave openings,they are usually entirely void of all gangue, being simply a deposit Fig. Cross-section of pipe-vein.—Side , galena, and clay. of block mineral. Mining in these two deposits is very precari-ous, as they are very rich for short distances, and then suddenly, SPELTER PRODUCTION. 125 without any warning, all traces of the ore disappear. I am ac-quainted with no successful mining in these two deposits. Besides the above, there are several other modes of occurrence ofthe lead ore, but they possess no economic value, and are only in-teresting to the scientist. Tlie most interesting of this class is the occurrence of galena incoal found in Moniteau County. I have not yet visited this point,but possess a full suit of specimens, and can vouch for this mode ofoccurrence, which is thus described : There is a bed of hard, densecannel coal forty feet in thickness, traversed by a network of veinscrossing each other at every angle. These veins were formed afterthe coal and are now filled with galena, zinc blende, and calcspar,presenting a very conglomeritic
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Keywords: ., bo, bookcentury1800, bookdecade1870, booksubjectmineralindustries
