DIABASE –TEMPERED WOODLANDS PERIOD CERAMICS FROM THE FORT BRAGG REGION OF THE NORTH CAROLINA SANDHILLS: A CERAMIC PETROLOGY STUDY

Woodland Period (1000 B.C. – 1600 A.D) ceramics from the Fort Bragg region of the North Carolina Sandhills represent a variety of source materials and manufacturing styles. During a long-term study to investigate regional sources for clays and tempers used in the manufacture of these pots, four sherds (Middle Woodland Period; Yadkin series) were found to be dominated by calcium plagioclase and pyroxene mineral fragments and diabase rock fragments. This is in marked contrast to the quartz-dominated mineralogy of the majority of Woodland Period ceramics of this region. In addition, these sherds are geochemically distinct from the other 66 INAA-analyzed Woodland sherds.

The aplastic components (temper) were identified as minerals (pyroxene and calcium plagioclase) and diabase rock fragments. In sherd JMH-006, the diabase fragments (>30 modal%) are unaltered and plagioclase and pyroxene mineral fragments are blocky and subangular. In the three other sherds the aplastic mineral grains are pyroxene + plagioclase, but the rock fragments are slightly altered and there is a small amount of fine to medium subangular quartz. The abundance of the individual temper components varied among the sherds, however the components were all represented. All of these sherds are reduced and have an overall black to black-gray color, suggesting firing in a poorly oxygenated environment.

These sherds were found in three different Piedmont drainages (Yadkin, Haw, and Lower Little) of the Cape Fear River basin. Two Early Jurassic igneous dike swarms cut across the eastern Piedmont, and are classified as olivine diabase or quartz diabase. However, the majority of these dikes are not exposed at the surface and locations where this occurs and would result in potential clay + temper materials for pot manufacture are rare. These sherds represent localized manufacture from materials acquired in unique environments and later transport, as indicated by the geographically separated locations where they were found.