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William A. Lovis Gerald R. Urquhart Maria E. Raviele John P. Hart 《Journal of archaeological science》2011
Among the multiple proxies for detecting maize in precontact economies is the use of δ13C analysis of carbonized residues from ceramic cooking vessels. Although maize horticulture was widely established in Eastern North America (ENA) by A.D. 1000, there are carbonized residues from ceramic assemblages after this date that lack the elevated δ13C values indicative of the presence of maize. This may be due to the true absence of maize, or other factors including the masking of maize. Prior experimental research by Hart et al. demonstrated that the addition of C3 plants or consumers to two part mixes with maize can mask maize presence even when maize is the dominant ingredient. Here we investigate the effect of alkali processing of maize (nixtamalization) on δ13C using the widespread ENA process of boiling maize kernels with wood ash, a C3 product, to create hominy. Our experiments test whether or not the process of hardwood ash nixtamalization can mask the presence of maize in adhering carbonized residues by depleting δ13C values, and whether there is a reciprocal δ13C enrichment effect on the hardwood ash employed in nixtamalization. Overall, there is substantial δ13C depletion of residues when maize is cooked with hardwood ash, and hardwood ash cooked with maize shows the reciprocal enrichment. Therefore, the depleted values after the adoption of maize may be false negatives due to the nixtamalization process. 相似文献
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The adoption of maize in northeastern North America is often seen as a catalyst for the development of settled village life. In this review we develop a theoretical framework centered on shifting-balance theory (SBT) and domesticated landscapes through which to understand the context for the adoption of maize agriculture in the Northeast. We review micro- and macrobotanical evidence and stable carbon isotope data from various sources to reevaluate maize histories and adoption trajectories. These data are coupled with contributions of subregionally significant predecessor plants, such as those constituting the Eastern Agricultural Complex, and wild rice. We find no evidence for rapid transitions to settled village life as a result of maize adoption. Maize was grown for centuries before settled village agricultural systems evolved. It was grown for a sufficiently long time that the potential for local selection leading to Northern Flint is a viable working hypothesis. We call for a refocusing of research questions and a systematic application of contemporary techniques as a means by which to strengthen future inferences based on comparative information sets. 相似文献
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John P. Hart Gerald R. Urquhart Robert S. Feranec William A. Lovis 《Journal of archaeological science》2009,36(10):2206-2212
Bulk δ13C values on charred cooking residues adhering to pottery sherd interior surfaces have been used as a source of information on the histories of maize in various locations in the western hemisphere. This approach is based on an assumption of a linear relationship between the percent maize in the resource mix cooked in a pot and δ13C. Previous experiments suggest that this relationship is non-linear, and maize may not be identified from bulk δ13C values even when it contributed substantially to the resource mix. A second round of experiments, presented here, indicates that the mobilization of carbon from maize and C3 resources over time is the critical variable in residue formation and the resulting bulk δ13C value. This is influenced by the form of maize being cooked. 相似文献