Wolf Den Mountain Rhyolite, Uwharrie Mountain, 31MG0639, North Carolina.
Wolf Den Mountain rhyolite occurs on two large mountains in the Uwharrie National Forest, near the eastern banks of the Yadkin River, North Carolina. This sample was collected from site 31MG639.
This plagioclase-porphyritic rhyolite is a dark gray to medium dark gray in color, with visible scattered white phenocrysts of plagioclase feldspar mess than 3 mm in diameter in an aphanitic matrix. The phenocrysts rarely constitute more than 5% of the sample. In thin section, the individual and groups of crystals occur in a microscrystalline matrix, mainly composed of feldspar and quartz with some biotite. With surface weathering the phenocrysts become a still more visible grayish-white color. Extremely old and weathered debris exhibit a chalky grayish-white exterior. (Daniel & Butler 1996).
Daniel reported that Uwharrie rhyolite is distributed widely across the piedmont of North Carolina and down into South Carolina.
Uwharrie rhyolite was used from Early Archaic through the Late Woodland periods.
Prepared By Egloff 2008