THE PETROFABRIC CONSTRAINTS ON THE DEVELOPMENT OF PRECONTACT QUARTZ MYLONITE QUARRIES IN NORTH CAROLINA

Seniard Creek Burn is a high elevation (2800-3200 AMSL), steep slope (50-60%) landscape exposed by forest fires and logging within the Dunsmore Creek quadrangle, North Carolina. The area is underlain by the Cambrian Ashe Metamorphic Suite, bearing chlorite/anthophyllite/magnetite schists, micropegmatite, metapelite granulites; including migmatites and rocks of tronjhemitic affinity.

General strike is 230°-285°, with biotite foliation outlining NE/SW trending fold limbs, and NW/SE dips. Prehistoric quarries are developed within two aprons of deformation features bearing rods, mullions, and block boudinage; all rolled into a ductile, coarse grained, biotite/magnetite-bearing schist. Boudins occur in metaquartzites and mylonitized quartz veins.

Preliminary excavations revealed two quarry tool and instrument types. These include large (10-15 kg), flaked, ground and vitrified extraction instruments; as well as elongate spatula-shaped objects with tapering edges. Quarry backfill piles abound in these two classes of objects. The first class has been interpreted as impact objects, fashioned from quartzite of the upper boudin apron. The second class of instruments are coarse grained biotite-schists and have been inferred as pry-bars employed as plug-and-feather wedges. Throughout the quarries, declivities exist where large block boudins were extracted. Many of the rock outcrop surfaces are rubified from repeated firing.

Quarry products include two classes of stone tools; varieties of adzes and a range of picks. Four types of adzes exist, including elongate tapering plano-convex, bifacially flaked, rectangular to square tablet-shaped, and elongate tapering flaked lozenge-shaped. The picks are elongate, spatula-shaped, flaked and ground; thin, tapering, bifacially flaked; large and small percussion; and cylindrical flaked, ground and tapered.

Quarry backfill produces bifacially flaked objects, unifacial scrapers, flakes, and boudinage fragments. Analysis suggests that quarry tools are designed from a template, baked in the fabric of the various boudinage structures. Remnants of boudinage surfaces remain on resulting artifacts. The objects are fashioned along the long axis of the boudins, and flaked within the direction of foliation present in the original boudin.