Trade more extensively than thought

objects to their sources by comparing their chemical signatures, or ‘fingerprints’.

Using Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LAICPMS), researchers at Ball State, the Field Museum and the New Jersey State Museum determined the chemical makeup of the copper band was most similar to sources found near the Great Lakes. While archeologists had long known copper was exchanged out of the Great Lakes region, the discovery made by Sanger and his colleagues extended previously documented boundaries of Archaic Period copper exchange by nearly 1,000 kilometers.

The use of cremation is also notable, as this practice is virtually absent in the Southeast US during the Archaic period, yet quite common further to the north, including in the Great Lakes, where the copper originated. The co-occurrence of copper use and cremation practices suggests, according to Sanger and colleagues, that these two regions were more closely linked than previously assumed. The possibility that the two regions shared cosmological worldviews or religious practices would suggest direct connections across huge amounts of space.

According to the authors, these findings lend insight on emergent patterns of hierarchical social organization in the Archaic Southeast US.

“Defining social complexity is always difficult — but our research shows that people were organized to a degree that allowed the formation of vast trade networks spanning half of a continent more than 3,000 years ago,” said Sanger. “Considering that these trade networks likely moved both information and objects, we argue that they were not simple ‘down the line’ exchanges — meaning that objects would slowly move between people over large amounts of time, perhaps through trade between friends and neighbors or as inherited items when someone died. Rather, the movement of information across more than 1,500 kilometers suggests that exchange networks were more formal and direct. Such formal and direct trade networks suggest sustained relations between diverse communities, which must have been sustained by relatively complex social institutions. We assume these social institutions were religious or ritual in nature considering that we are looking at a multiple-person cremation in the center of a circular deposit of food remains.”

Sanger and his colleagues at the University of Georgia and Northern Kentucky University have recently been granted a $300,000 grant from the National Science Foundation to study an additional 12 shell rings.

“With this grant, myself and my colleagues will begin an ambitious field program and associated analyses to determine whether our findings were unique or part of a broader pattern in the American Southeast,” said Sanger.

The paper, “Early metal use and social organization in the southeastern US,” was published in the Proceedings of the National Academy of Sciences.