Following from this, recent studies have suggested that archaeological freshwater shell and shell-tempered pottery can be sourced via chemical analyses of trace elements bound within freshwater shell crystal structure. For example, obsidian formed from a volcanic eruption will have a distinct chemical signature, so that ancient tools made of the material can be traced to a particular obsidian bed (e.g., Arakawa et al., 2011 Argote-Espino et al., 2012). The broader implications are: 1) that diagenetic alteration does not hinder chemical sourcing of shell at Lyon's Bluff, and 2) that certain trace elements are more reliable than others, namely Sr 2+, Al 2+, Ba 2+, and Mn 2+, when conducting trace element provenance studies on fired-shell temper.Īrchaeologists have long been interested in tracing artifacts to their places of origin, which relies on identifying physical or chemical properties related to the point of origin. ICP–MS data show that certain trace elements within the modern shell maintain their concentration after firing at 500 ☌. Microscopy results indicate a pristine aragonite crystal structure in the archaeological samples. ICP–MS analysis also was conducted on a modern freshwater shell subjected to kiln firing. Thin-section petrography, X-ray diffraction, cathodoluminescence, and scanning electron microscopy analyses were conducted on archaeological shell from four natural layers from Unit 20N20W, over a depth of 80 cm and spanning 450 years. This study considers the chemical alteration of archaeological freshwater shell above the water table at the Lyon's Bluff site (22OK520), a single-mound and village complex located in east-central Mississippi, and the changes in trace element concentrations between unfired and fired shell.

The Provenance by Joe Lyon