. Transactions. tions have extended to some depthbelow local ground-water level into the unaltered sulphideores, sphalerite and galenite. New river cuts across an anti-clinal of the Shenandoah limestone near the mines. The ac-cumulation of the ores is in the magnesian limestone strata,which dip about 45° SE., and form the corresponding limb ofa faulted anticline. About miles east of these mines, onthe same (south) side of New river, and about a mile therefrom,are located the Bertha zinc-mines. Here, operations wereentirely limited to surface mining of oxidized ores over a belt 706 LEAD- AN
. Transactions. tions have extended to some depthbelow local ground-water level into the unaltered sulphideores, sphalerite and galenite. New river cuts across an anti-clinal of the Shenandoah limestone near the mines. The ac-cumulation of the ores is in the magnesian limestone strata,which dip about 45° SE., and form the corresponding limb ofa faulted anticline. About miles east of these mines, onthe same (south) side of New river, and about a mile therefrom,are located the Bertha zinc-mines. Here, operations wereentirely limited to surface mining of oxidized ores over a belt 706 LEAD- AND ZINC-DEPOSITS VIRGINIA-TENNESSEE REGION. about 1,500 ft. wide, extending in the direction of the strike ofthe limestone, which is south 35° to 40° west. The dip of thelimestone, where measured, was 25° N¥., with flatter dips re-ported. Recent prospecting at Cedar Springs, about 20 miles west ofAustinville, in the extreme southwestern corner of Wythecounty, Va., indicates that the ores occur on or near the. Sphalerite Limestonefragments ? Calcite andDolomite Fig. 15.—Brecciated Limestone Cemented with Calcite-Dolomite andBlende. Koseberry Zinc-Mines, Mascot, Tenn. faulted crest of an anticline. The distribution, therefore, ofthe ores in Wythe county is along a narrow belt which crossesthe southern part of the county in a north of east belt is a structure zone—one of anticlinal folding andfaulting—and the ores are deposited along and near the faultin the shattered and recemented limestone of the anticline. Precisely similar relations obtain in the Tennessee part ofthe district. At Kew Prospect, formerly known as Lead Mine LEAD- AND ZINC-DEPOSITS VIRGINIA-TENNESSEE REGION. 707 Bend, near Powell river, in Union county, Tenn., the ore-bear-ing area forms a narrow zone trending north 50° E., and lyingjust south of the crest of the Powell anticline, in which therocks are crushed and Six miles southwest of Taze-well, in Claiborne county, Tenn., the
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Keywords: ., bo, bookcentury1800, bookdecade1870, booksubjectmineralindustries
