English: Plate XXIII B, Original caption: "Bowlder outcrop of coarse-grained granite 3 miles southwest of
Heath Springs, SC."
Text from the volume referring to this figure:
Beginning about l 1/2 miles southwest of Heath Springs and extending for a considerable distance along the highway to the Excelsior quarry is a coarse-grained porphyritic biotite granite of a mixed greenish-yellow and reddish-gray color, similar to that near Lilesville, Anson County, S. C. ... As shown in Plate XXIII, B, the granite is exposed in places in large bowlder outcrops. It has not been quarried, but its color and texture are such as to render it of value as a decorative stone. Its minerals are potash feldspar (orthoclase and microcline), much soda-lime feldspar (oligoclase), quartz, and biotite, together with accessory apatite, zircon, and iron oxide and secondary chlorite, epidote, a little colorless mica, and kaolin. The potash feldspar shows Carlsbad twinning. The plagioclase feldspar, which is equal to or greater in amount than the potash feldspar, is partly altered.