Maize detection in absorbed pottery residues: Development and archaeological application.

摘要

An archaeometric technique for the detection of maize products in absorbed pottery residues is developed in this dissertation. The technique is applied to 135 pottery samples from 17 sites along the Mississippi Valley, dating from the Middle Woodland through the Mississippian period.; Absorbed pottery residues are the compounds from prehistoric materials processed in a pot that absorb into the matrix of the pottery vessel during processing and undergo weak chemical interactions with the clay and inclusion particles. As a result, these prehistoric compounds remain relatively unmodified in the wall of the pottery vessel until extraction, purification, and analysis. Using gas chromatography/mass spectrometry (GC/MS) and isotope ratio monitoring gas chromatography/mass spectrometry (irm-GCMS), compound-specific carbon isotope values are obtained from the various compounds in the absorbed residue. The long-chain alcohol n-dotriacontanol is discovered over the course of this project as a compound that is unique to plants, abundant in maize, and rare in most other plants in Midwestern and Eastern North America. The δ13C of n-dotriacontanol, if present, can be used to detect the presence of maize products in a residue.; Of 106 sherds containing residue in this study, eight contained maize products. As a result, no reliable correlation could be determined between pottery change along the Mississippi and the adoption of widespread maize use in that region. The unexpectedly small amount of maize in the sample, when combined with the interpretations of the contents of the pots in this study, suggests that diet along the Mississippi Valley was strongly dependent on a variety of plants. The results of this analysis suggest that during the Emergent Mississippian and Mississippian periods along the Mississippi Valley, maize was an addition to a varied, plant-based diet that had not changed extensively since the Late Woodland period. During this time period, at least, maize did not completely revolutionize diets along the Mississippi.