National Science Foundation funds will support Dr. Wesley D. Stoner in analyses that will improve methods of pottery sourcing and chemical characterization using a well-known case study in the Basin of Mexico. Through chemical and mineral analyses, archaeologists can trace ceramics used and discarded during the human past back to the source of production. Connecting consumers and producers essentially reconstructs economic exchange, which normally remains invisible in the archaeological record. The exchange of goods among human groups has provided data to better understand the foundations ancient civilizations, the accumulation of power into the hands of the few, and the collapse of some of the most powerful states and empires to have ever graced this earth. The Basin of Mexico is no exception, trade reconstructions there have contributed to knowledge of Mexico's very first exchange systems and the flows of trade and tribute commanded by the Aztec Empire. In the past, most of these analyses have been undertaken through neutron activation analysis (NAA).
While NAA is among the most commonly applied ceramic compositional techniques, it is not always the best tool to answer all research questions. Recent ceramic studies using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) have demonstrated that targeted analysis of components within the ceramic paste can augment, and sometimes supersede, the utility of bulk NAA data. The principal purpose of the proposed study is to determine whether data for specific components of the paste (i.e. temper choice, mixing of temper and clays, natural aplastic inclusions) can potentially surpass the provenance capabilities of bulk chemical data garnered from NAA. I will employ LA-ICP-MS to collect data on both clay and aplastic (temper and natural inclusions) fractions within tempered ceramics from the Basin of Mexico. Petrography, undertaken through image analysis with a digital microscope, will serve as a tool to interpret the chemical data in this study.
Archaeologists have not commonly used LA-ICP-MS to study ceramic pastes, so method development is still largely in an experimental phase. Image analysis of petrographic thinsection photographs is also a relatively recent technological advancement for use in characterizing archaeological ceramics. The combination of these two techniques provides detailed information on individual components of the paste so that behavioral stages of pottery production - from raw material procurement and mixing of pastes to decoration with slips and paints - become visible to the analyst. The proposed research promises to identify methods for more efficient and detailed provenance analysis.
This research will produce standard protocol manuals to guide LA-ICP-MS and petrographic studies at the University of Missouri Research Reactor (MURR). These manuals will be reduced for broad dissemination through international journal publications and perhaps a book manuscript. This project will also serve as the basis to train students and staff at the University of Missouri in both LA-ICP-MS and petrographic methods. Additionally, a Mexican student will travel to MURR to assist in all data collection. Through this student, knowledge of the techniques will spread internationally.
