The rocks in the James River Face Wilderness are shales and quartzites that overlie a meta-igneous basement. They are folded into a large southwestward-plunging anticline that is cut off on the east and south by an extensive thrust fault that brings old basement rocks over the younger sedimentary rocks. Geochemical studies of stream sediments, soils, and rocks do not reveal any unusually high metal concentrations, but a large resource of metallurgical-grade quartzite and shale suitable for structural clay products and lightweight aggregate is in the wilderness. Antietam (Erwin) Quartzite has been quarried at three sites in the wilderness as raw material for silicon used in the manufacture of ferrosilicon. Other uses included crushed rock for concrete aggregate, road metal, and railroad ballast, and sand for cement and mortar. Potential uses include ganister for silica brick and specialty sands such as filter and furnace sand. Firing tests on samples of shale from the Harpers (Hampton) Formation show that it could be used for the manufacture of brick and as lightweight aggregate. Of marginal economic interest are heavy-mineral layers in the basal Unicoi (Weverton) Formation.
