ASSESSING NATURAL CLAY COMPOSITION IN THE VALLEY OF OAXACA AS A BASIS FOR CERAMIC PROVENANCE STUDIES

The Oaxaca Clay Survey was initiated to provide baseline data on clay composition within the Valley of Oaxaca, Mexico, to assist in provenance determination of prehistoric ceramics. Natural clays were sampled from 135 locations throughout the valley, and analysed using INAA in combination with ceramic petrography. Observed geographical trends in trace‐element and mineralogical composition confirm that while parent material (surficial geology) strongly affects clay composition, a continuum of variation exists within the valley. The study develops and tests a continuous spatial model of clay composition that provides greater resolution in ceramic sourcing than bedrock alone. By establishing a regional framework for Oaxaca Valley clays, the survey will support significant advances in our understanding of pottery production and exchange within the valley, and provide a more robust means for monitoring exchange between the valley and neighbouring regions.     

NEW PETROGRAPHIC EVIDENCE PERTAINING TO CERAMIC PRODUCTION AND IMPORTATION AT THE OLMEC SITE OF SAN LORENZO*

This paper reports the results of petrographic analyses of 41 new pottery thin sections from San Lorenzo. The resulting compositional data provide an important new context for evaluating the disputed status of carved vessels previously identified as imports to the site. By comparing local and Oaxaca highlands pottery, the disputed vessels are shown to be (a) compositionally distinct from San Lorenzo pottery and (b) similar to highland pottery. San Lorenzo was not just an exporter but also an importer of pottery vessels, a finding relevant to consideration of San Lorenzo's role in the production and exchange of ceramics in Early Formative Mesoamerica.     

The Study of Local Public Economies: Multi‐organizational,Multi‐level Institutional Analysis and Development

One important extension of the IAD framework has been to the study of local public economies. These are multi‐organizational, multi‐level arrangements defined as the set of governmental jurisdictions, public and nonprofit agencies, and private firms that interact in various patterns to provide and produce public goods and services within a specific locality or region. Commonly, the localities or regions studied from this perspective have been U.S. metropolitan areas, often defined as a central city and its surrounding or adjoining county. Localities can be delineated, however, on various terms, and in the IAD framework, it is the geo‐physical nature of a locality that, in substantial part, drives the analysis. One of the strengths of the approach is its capacity to explain local variations in public organization as a function of the geo‐physical diversity of localities, while at the same time developing empirical generalizations and normative principles that apply across diverse regions. What, for example, might the organization and governance of a complex metropolitan area have in common with the organization and governance of a complex protected area, such as the greater Yellowstone eco‐region or the Adirondack Park? Construing both sorts of regions as local public economies can enhance our overall understanding of public organization at the same time that it permits a more nuanced understanding of diverse localities. Such work contributes to the ongoing IAD project of “understanding institutional diversity.”     

The abrasion of modern and archaeological bones by mobile sediments: the importance of transport modes

Fresh, weathered, archaeological and fossilized bones were subjected to a series of abrasion experiments using fine sand in an annular flume in order to link bone-surface abrasion to flow regimes and sediment transport modes, compare these effects on bones of different states, and quantify the extent and types of wear occurring. Flow velocities were chosen to replicate the predominant transport modes of bedload, saltation and suspension.Comparative scanning electron microscopic image analysis was performed to assess the degree and type of wear occurring on each bone type for the different transport modes over a range of exposure periods from 24 to 72 h.These preliminary investigations have shown that both the amount and type of wear experienced was related to the bone type, duration of exposure and the mode of sediment transport with wear being the result of deformation, rather than cutting wear.The formation of scour pits in the sand bed on the upstream side of the bone samples significantly reduced wear, and appears to be an important control mechanism for impact related wear that has been overlooked until now.     

An Appeal from the New to the Old Historicists

Book reviewed in this article:
Jürgen Pieters, Moments Of Negotiation: The New Historicism Of Stephen Greenblatt     

The use of multiple discriminant analysis in classifying prehistoric phytolith assemblages recovered from cooking residues

In the investigation of the dispersal of maize (Zea mays ssp. mays) from south-central Mexico to the northern and southern limits of agriculture in the Western Hemisphere archaeologists and paleoethnobotanists are increasingly turning to the microbotanical record. Recent analysis of phytolith assemblages from charred cooking residues on pottery sherds in central New York recovered using 209 rondel phytolith variables has identified maize as early as 2270 ± 35 B.P. In this article we use discriminant analysis to re-classify these rondel phytolith assemblages resulting in only seven variables. The results are consistent with those achieved earlier using many more variables and a less formal statistical approach in terms of classification and in similarity of the original and reduced data matrix as seen by the Mantel test and cluster analyses.