. Economic Papers. 40° SE. The pegmatite is coarsely crystallized next to the hangingwall and grades into fine-grained pegmatite or coarse granite on the lowerside. Only the coarse pegmatite, called the vein, is mined; this pinchesand swells between 1 and 4 feet in thickness. The mine was first workedby open cuts on the outcrop and shallow inclines. Later a drift was runabout 150 feet from the outcrop lower down on the hillside, and portionsof the vein were stoped out to the open cut above. Figure 19 is a sectionin the plane of the vein and shows the nature of the work at the time ofvisit. The
. Economic Papers. 40° SE. The pegmatite is coarsely crystallized next to the hangingwall and grades into fine-grained pegmatite or coarse granite on the lowerside. Only the coarse pegmatite, called the vein, is mined; this pinchesand swells between 1 and 4 feet in thickness. The mine was first workedby open cuts on the outcrop and shallow inclines. Later a drift was runabout 150 feet from the outcrop lower down on the hillside, and portionsof the vein were stoped out to the open cut above. Figure 19 is a sectionin the plane of the vein and shows the nature of the work at the time ofvisit. The mica has a dark-green color and is specked, some abundantly,with dendritic spots of magnetite. Some crystals of large size are found,and one weighing 165 pounds was obtained at the time of visit in block measured roughly 12 by 20 inches and was 30 inches mica was split and graded at the mine and shipped to electrical man-ufacturers. The splitting and rough trimming were done chiefly by Figure 19.—Section in plane of pegmatite at Knob mine, Mitchell County, N. C. W. W. Wiseman Mine—The Wiseman mine is 2 miles northeast ofSpruce Pine, on Beaver Creek. According to Mr. Mart Wiseman it wasopened by James Wiseman and John Pendley in 1875. These men removed$2,000 or $3,000 worth of mica in one years work. Later the mine wasoperated by Lum Blalock and Luke Lewis, and still later by other 1890 the mine went into the hands of the Southern Mica early workings consisted of a shaft carried down 30 feet and a tunnel40 feet long along the vein. At the time of visit (1904) the old workings had caved in badly, leavinga pit resembling an old open cut. The more recent workings of the South-ern Mica Company were still open, however. A crosscut tunnel some 250feet long had been driven into the vein, along which drifts with extensivestoping were run. The country rock is highly schistose mica gneiss whichhas a varied dip and strike where it
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