Sourcing Prehistoric Ceramics from Western Illinois Through FT-IR Spectroscopy and Developed Chemometric Methods

Abstract

This research examines the potential for determining the source of clays used in the production of prehistoric ceramics from the American Bottom and Illinois Valley through infrared (IR) microscopy. IR microscopy was employed to measure the composition of reference clays and prehistoric sherds over a spectral range of 1,300–600 cm -1. The data analysis consisted of two parts: spectral comparison to examine solid-state structural changes during firing of the reference clay, and the development of chemometric methods, via cluster analysis, to determine the relative degree of heterogeneity based on the composition of these reference sets. The data analysis included 416 individual spectra obtained from 64 prehistoric sherds and 19 reference clay samples. Initial results show a high degree of correspondence between the hypothesized origin of the prehistoric sherds and the geographical region of the spectral measurements; however, the correspondence decreases as the clay source comparison is localized to regions within Illinois.

Access to the article at the Illinois Archaeological Survey. Select the 2014 volume.