GEOLOGY OF AN ANCIENT NATIVE AMERICAN BEDROCK QUARRY, WESTERN NORTH CAROLINA BLUE RIDGE

In 2019, a unique archaeological site was discovered on steep terrain near Seniard Mountain in the Blue Ridge Mountains ~20 km SW of Asheville, North Carolina. The site was first discovered when artifacts from an ancient indigenous quarry site were inadvertently exposed along a bulldozer scar cut as a firebreak in the Pisgah National Forest. The artifacts include Guilford points, hammerstones, bi-facial flaked cores, and picks. Morphologically, these Guilford points likely indicate an age of 6000 to 8000 ybp. In this study, we mapped the geology of the site as well as conducted structural and petrographic analysis.

The Seniard Mountain site is underlain by metamorphic rocks of the Ashe Metamorphic Suite and includes both paragneiss and muscovite-biotite-rich gneiss. The micaceous gneiss occurs in the southwest part of the study area, while to the northeast, the micaceous gneiss grades into paragneiss, likely derived from a sandstone and graywacke protolith. These rocks are well-foliated and the dominant foliation is folded into a sequence of asymmetric folds that verge to the northeast and plunge to the southeast. The main foliation is cut by shear bands and multiple sets of later brittle fractures and faults. Boudinage quartz veins occur in the gneisses and are the source of the artifacts. The microstructures of the boudinaged quartz veins are critical for the textures necessary to produce quality stone tools.