. Transactions. often characterized by some impregnation of theore. The relation of the fluorite-quartz lenses to the enclos-ing schists are shown in Fig. 25. The ore, consisting of blende and galenite, occurs principallyin the fluorite-quartz lenses, although the schists next to thelenses is often more or less mineralized. The blende and galenitemay occur in separate bands and irregular masses distributedthrough the lenses; or they may occur intimately admixed ina single band or mass in the same lens. Fig. 26, which is adrawing of a large mass broken from one of the lenses, showsthe typical o
. Transactions. often characterized by some impregnation of theore. The relation of the fluorite-quartz lenses to the enclos-ing schists are shown in Fig. 25. The ore, consisting of blende and galenite, occurs principallyin the fluorite-quartz lenses, although the schists next to thelenses is often more or less mineralized. The blende and galenitemay occur in separate bands and irregular masses distributedthrough the lenses; or they may occur intimately admixed ina single band or mass in the same lens. Fig. 26, which is adrawing of a large mass broken from one of the lenses, showsthe typical occurrence. On working-out the ore, the two wallsare entirely smooth and solid. Enough work has probably not 720 LEAD- AND ZINC-DEPOSITS VIRGINIA-TENNESSEE REGION. yet been done to indicate the true relations of the ores, blendeand galenite; but, so far as developments extend, there seems tobe some tendency in the galenite to follow or occur close to thefoot-wall and the blende the hanging-wall. This relation may. 5CHI5T KV • ^V\A^ FLUOR SPAR AND QUARTZ Fig. 25.—Diagram Illustrating the Type of Fissure-Vein Formed atthe Albemarle Zinc- and Lead-Mine, Albemarle County, Va. not continue on depth. It is the belief of the miners that thefluorite and blende increase in depth, and that the quartz andgalenite decrease. Sufficient depth has not been reached, norenough underground work done, to establish any relations ofthe ores to each other and to the gangue. LEAD- AND ZINC-DEPOSITS VIRGINIA-TENNESSEE REGION. 721 In addition to the principal ores, blende and galenite, somechalcopyrite occurs and some smithsonite. Some years ago,cerussite and azurite from the dumps were reported. Thegalenite is argentiferous, and arsenic and antimony are reportedin very small quantities. Fluorite is the principal gangue-
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Keywords: ., bo, bookcentury1800, bookdecade1870, booksubjectmineralindustries
