Elemental analysis of Late Archaic copper from the McQueen Shell Ring, St. Catherine's Island, Georgia

Abstract

Excavations conducted at the McQueen Shell Ring on St. Catherine's Island off the coast of Georgia recovered several fragments of a copper artifact. These fragments represent an artifact made from a thin sheet of copper, and were recovered from a Late Archaic feature with calibrated radiocarbon dates placing its use between 2300 and 1800 cal. BC. Seven of these fragments were analyzed at the Elemental Analysis Facility of the Chicago Field Museum of Natural History to determine elemental composition with the intent of identifying probable sources for the copper from which the artifact was manufactured. Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) was used to collect elemental composition data for these seven fragments as well as from geological source samples representing Lake Superior, the southern and central Appalachians, and the Canadian Maritimes. Several statistical analyses were performed on the resulting data by varying test assumptions and parameters. All analyses place the most likely source for the Georgian artifact in the Lake Superior region far to the north rather than in the closer sources of the Appalachians, requiring a more complex explanatory framework to account for this long distance interaction or acquisition.