Non-destructive chemical characterization of ceramic sherds from Shipwreck 31CR314 and Brunswick Town, North Carolina

The purpose of this study was to chemically and texturally characterize ceramic oil jar sherds from North Carolina Shipwreck 31CR314 and to explore the utility of environmental scanning electron microscopy/X-ray energy dispersive spectrometry (SEM/EDS) for that purpose. The oil jar sherds, widely dispersed about Shipwreck 31CR314, are morphologically similar to each other, which suggests they could be from a single jar, but with so few joins this could not be concluded with certainty. Therefore, an aim of this study was to investigate whether chemical or textural characterization of the sherds might reveal unique attributes that could distinguish individual jars: results of characterization perhaps could give information on their Origin and possibly site formation processes, Such as whether environmental forces could have scattered sherds of a single jar during and after sinking of the ship. Previous Studies have indicated this shipwreck is likely the remnants of the Queen Anne's Revenge, flagship of the pirate Blackbeard. Sherds from this shipwreck were compared with similar oil jar sherds excavated from a land site, Brunswick Town, North Carolina, to explore the use of composition and texture as hallmarks. The chemical components of the artifacts were determined by SEM/EDS. This method of analysis is valuable for archaeological research because it is rapid and non-destructive to the ceramic artifacts. Both groups of lead-glazed coarse red earthenware sherds were texturally similar except for the glazed sides of all 31CR314 sherds that exhibited small tracks of unique crescent-shaped marks. These marks may be due to manufacturing effects and immersion in seawater, and the marks may serve as hallmarks for individual jars or potentially individual manufacturers. The sherds were generally Similar in composition, but the two groups exhibited distinct differences. Brunswick Town sherds consistently contained more phosphate On unglazed sides, an average 1.46 wt.% P2O5, and also contained trace elements not detected in the Shipwreck 31CR314 sherds. These distinct differences could be due to different manufacturing origins for Shipwreck 31CR314 and Brunswick Town ceramics but also could reflect their subjection to different environments during use and loss prior to archaeological recovery. (C) 2008 Elsevier Ltd. All rights reserved.