OF SOUTH CAROLINA. 69 
CHAPTER ILI. 
Stratified Rocks. Gneiss—Hornblende Rock.—Mica Slate—Limestone of the Gneiss—Lime- 
stone of the Mica Slate— Quartz Rock.—Iron Ores.—Magnetic Ores.—Specular Ores.—Brown 
Hematite—Bog Ore. 
After this brief survey of the unstratified and igneous rocks of the State, we have next to con- 
sider the relations and extent of the stratified rocks, beginning with the metamorphic series. 
Gneiss, it will be recollected, is, like granite, a triple aggregate of quartz, feldspar, and mica— 
these ingredients varying very much both in size and proportion. In the southern portion of the 
primary region of the State, the strata composed of this rock are thin, fine-grained, and very dis- 
tinctly stratified. As we proceed upwards towards the mountains, as a general rule, the rock 
becomes coarser, more feldspathic, and very frequently porphyritic—having large, lamellar crystals of 
feldspar embedded, which frequently preserve a certain degree of parallelism of their axes. It is less 
subject to disintegration than the unstratified rocks of the State, and, when weathered, the feldspar, 
and not the quartz, is found in relief on the surface, after the other constituents have crumbled 
away. Among the mountains of Pickens gneiss is sometimes seen with the feldspar lenticular, 
as if compressed between the laminz of the rock, or as if it had been introduced during the con- 
solidation of the rock, and had thus pushed the layers of mica apart. Gneiss is often much con- 
torted, and where the’mica is black and the other constituent minerals of a light color, the appear- 
ance presented by the rock is striking. Localities of this variety may be seen at Morton’s Mill, on 
Long-cane, Abbeville District, at the Mountain Shoals of Enoree, and higher up, at Van Patton’s 
Shoals. = 
Fig. 13. ; 
Fig. 13 represents a specimen of contorted gneiss, from Long-cane. Such an effect as this can 
only result from lateral pressure, while the rock was yet yielding. 
Of all the metamorphic rocks, gneiss is best developed in South Carolina; for, although its 
continuity is often interrupted, by the protrusion of the underlying granite, or the alternation of 
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