Kyanite, Sillimanite, and Andalusite Deposits of the Southeastern ...

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KYANITE DEPOSITS 93 of the syncline is represented by a long lens of coarse granular quartzite which carries only trace amounts of sillimanite. Small crystals of native sulfur occur locally in this quartzite. Sillimanite quartzite at this locality is strongly foliated; its principal constituents are quartz, fibrolite and coarser sillimanite, and, generally, white mica. In thin section sillimanite is seen to be present largely in the form of fibrolite which is intimately intergrown with quartz
94 KYANITE, SILLIMANITE, AND ANDALUSITE DEPOSITS, SOUTHEASTERN UNITED STATES parent relation to the Yorkville quartz monzonite. Kyanite-quartz veins are found only in kyanite quartzite. The distribution pattern of kyanite quartzite and the local compositional layering within the kyanite quartzite at Clubb Mountain suggest that here also the aluminum was indigenous to the sediment. The peculiar texture of the kyanite ore, the presence of numerous quartz veins locally containing lazulite and crandallite, and the presence in the ore of pyrophyllite and lazulite indicate that hydrothermal fluids were active in metamorphism here. The origin of the hydrothermal fluids is unknown, but it seems that their principal effect was to mobilize the aluminum already in the rock. OTHER MINERAL DEPOSITS The Kings Mountain district has long been known for its deposits of iron ore, barite, gold, and manganese. Pegmatites yielding commercial deposits of tin, spodumene, and mica (Keith and Sterrett, 1931; Kesler, 1942; Griffitts and Olson, 1953) are also of prime importance in this district; these deposits occur in a zone that extends through the city of Kings Mountain, 3 miles west of the Crowders Mountain-Henry Knob area. IRON The principal occurrence of magnetite in the Crowders Mountain-Henry Knob area is just west of Yellow Ridge (pi. 7). Here several deep pits were dug and ore produced during, or just before, the Civil War. This ore has a strong schistose structure; magnetite occurs sparingly on the dumps. Small amounts of magnetite also occur at the same stratigraphic position just south of Crowders Creek. Shallow prospects in white mica schist and biotite gneiss have been dug for magnetite 6,000 feet north of Henry Knob. Magnetite occurs commonly as small pieces of float in many parts of the area. Thin lenses of specular hematite occur near the center of Crowders Mountain (p. 89). Many old prospects have been made for hematite and magnetite along the crest of the ridge. The iron ore deposits of this region are more fully discussed by Nitze (1893) and by Keith and Sterrett (1931). BARITE The principal occurrences of barite are in a milelong belt southwest of Gasset Lake (pi. 7). They are described under the headings, "Lawton property/' "Craig property," and "Chimney place," by Van Horn, LeGrand, and McMurray (1949). These occurrences are part of the so-called Carolina barite belt extending from the vicinity of Gaffney, S.C., to the north end of Crowders Mountain. The Lawton property has been the most productive. Barite occurs typically as thin lenses along the foliation planes in schist. The present study indicates that barite mineralization at two localities was accompanied by local potash metasomatism. At these localities, thin veins of adularia and the pseudomorphic replacement of plagioclase by microcline attest to the introduction of potash in biotite schist. MANGANESE Little or no manganese has been produced from the Crowders Mountain-Henry Knob area. The principal occurrences of manganese are the manganiferous schist and accompanying fine-grained spessartite rock that occur as septa in the Yorkville quartz monzonite. Low-grade deposits of manganiferous schist occur north, southeast, and southwest of the Crowders Mountain-Henry Knob area (fig. 42); these have been described by Keith and Sterrett (1931) and by White (1944). GOLD Numerous small abandoned gold mines occur in the central part of the Crowders Mountain-Henry Knob area (pi. 7; Keith and Sterrett, 1931). For the most part these workings are overgrown and caved; limonitized country rock occurs on most of the dumps. Pardee and Park (1948) give brief accounts of the Patterson and Caledonia mines in the north-central part of the area. The abandoned Kings Mountain gold mine is located about 1 mile northwest of Lake Montonio. SOUTH CAROLINA CHEROKEE AND YORK COUNTIES Kyanite quartzite occurs at Jefferson Mountain in Cherokee County, a small knob about 150 feet high lying 13 miles west-southwest of Henry Knob. It is one of the group of kyanite quartzite deposits in the Kings Mountain quadrangle (Keith and Sterrett, 1931), but lies southwest of the area shown on plate 7. Bare ledges of kyanite quartzite are exposed in an area several hundred feet in diameter on top of the knob. Most of the rock is very fine grained quartzite that is cut by thin stringers, generally less than an eighth of an inch thick, of kyanite; these outcrops have weathered to smooth rounded surfaces because of the low kyanite content. On the west side of the knob is a ledge, about 8 feet thick, containing veinlets several inches thick and
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UNITED STATES DEPARTMENT OF THE INT
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IV Page Kyanite deposits Continued
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VI CONTENTS TABLES TABLE 1. Major d
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Type of mica Muscovite . . . Do....
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Kyanite, Sillimanite, and Andalusite Deposits of the Southeastern ...

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