Stuart Creek Gneiss (Conley, 1985). Light-gray to black and white, massive to irregularly-layered augen and flaser gneiss with anastamosing layers of mylonitic biotite schist, hornblende schist and foliated leucogranite. Augen gneiss is composed of microcline, plagioclase, and perthite porphyroclasts up to 4 cm across in a matrix of plagioclase, quartz, and biotite, with accessory titanite, epidote, hornblende, and opaque minerals. This rock was correlated with the Elk Park Group of the southwestern Blue Ridge by Espenshade and others (1975). Rankin and others (1971) obtained a lead-lead zircon age of 1192 Ma from a layered biotite gneiss unit in a similar stratigraphic position as the Stuart Creek but exposed in a quarry at Pilot Mountain, North Carolina, about 25 miles southwest of the Virginia-North Carolina boundary.