. Economic Papers. asmall streak of pegmatite 18 inches thick, which was probably the main veinpinching out. Figure 22 shows the extent of the work open for examinationat the time of visit. A large part of the stoping and drifts had caved inand could not be seen. The greater part of the vein above the tunnelsshown in the figure had been removed, however, and future work should bedirected to vein matter between old workings and to lower depths, easilyattained with facilities for draining. Tunnel No. 3 is probably 50 feethigher than No. 1. The mine produced a large quantity of small block mica,y
. Economic Papers. asmall streak of pegmatite 18 inches thick, which was probably the main veinpinching out. Figure 22 shows the extent of the work open for examinationat the time of visit. A large part of the stoping and drifts had caved inand could not be seen. The greater part of the vein above the tunnelsshown in the figure had been removed, however, and future work should bedirected to vein matter between old workings and to lower depths, easilyattained with facilities for draining. Tunnel No. 3 is probably 50 feethigher than No. 1. The mine produced a large quantity of small block mica,yielding sheets 1 by 2 and 3 by 4 inches. A number of larger blocks, yield-ing sheets 6 by 8 and more inches square, were found with the smaller ma- 62 MINING INDUSTRY. terial. Many small blocks of mica and one crystal over 10 inches thick anda foot wide was seen in the vein, embedded in feldspar. The mica has abeautiful clear rum color and is of the best grade. Most of the blocks yield sheets of perfect quality. 0-. Figure 22 —Plan of North Hardin mine, Ashe County, N. C. South Hardin Mine—The South Hardin mine is near the top of a smallmountain or hill about iy2 miles southwest of Beaver Creek. This minewas first opened by small pits, trenches, and a tunnel along the vein. Thesurface workings were at the summit of the hill and the tunnel on the out-crop about 40 feet lower down to the northeast. The mine was later oper- MINING INDUSTRY. 63 ated by a 30-foot shaft near the top of the hill and an open cut about 75feet long and 10 to 20 feet deep on the vein. The country rock of the region, like that of the North Hardin mine, amile to the northwest, is hornblende gneiss. The mica-bearing pegmatite isinclosed in a smaller mass of biotite mica gneiss included in the hornblendegneiss. The pegmatite is conformable with the schistosity of the inclosingformations, which strike due northeast and dip 50° SE. at this point. Thepegmatite is about 7 feet thick as exposed at the surface
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