%0 Journal Article %J Radiocarbon %D 2015 %T Fishing for Dog Food: Ethnographic and Ethnohistoric Insights on the Freshwater Reservoir in Northeastern North America %A Lovis, W. A. %A J. P. Hart %K Cooking Technology %K Diet %K Fish Processing %K Freshwater Reservoir Effect %X

A review of current research reveals multiple lines of evidence suggesting that no single freshwater reservoir offset (FRO) correction can be applied to accelerator mass spectrometer (AMS) ages obtained on carbonized food residue from cooking vessels. Systematically evaluating the regional presence, magnitude, and effects of a freshwater reservoir effect (FRE) is a demonstrably difficult analytic problem given the variation of ancient carbon reservoirs in both space and time within water bodies, and which should be performed in advance of AMS assays. In coastal and estuarine contexts, a priori partitioning FRE from known marine reservoir effects (MRE) is also necessary to eliminate potential mixed effects. Likewise, any FRE varies based on the proportional mix of resources producing the residues and the ancient carbon uptake of those products. Processing techniques are a significant component of assessing potential FRE, and each pot/cooking vessel is therefore an independent context requiring analytic evaluation. In northeastern North America, there is little ethnohistoric/ ethnographic evidence for fish boiling/stewing in ceramic cooking vessels; rather, fish were more often dried, smoked, or cooked for immediate consumption on open fires. Assays of fatty acids extracted from prehistoric vessel fabrics even on known fishing sites reveals no evidence for fish in the food mix. These observations suggest that the likelihoods of FRE in carbonized food residue in northeastern North America is therefore low, and that assays potentially suffering from FRO are minimal. In turn, this suggests that AMS ages from carbonized food residues are reliable unless analytically demonstrated otherwise for specific cases, and should take primacy over ages on other associated materials that have historically been employed for critical threshold chronological events.

%B Radiocarbon %V 57 %P 557-570 %G eng %U https://journals.uair.arizona.edu/index.php/radiocarbon/article/view/18352 %N 4 %& 557 %R 10.2458/azu_rc.57.18352 %0 Journal Article %J Journal of Archaeological Science %D 2011 %T Hardwood Ash Nixtamalization May Lead to False Negatives for the Presence of Maize by Depleting Bulk delta13C in Carbonized Residues %A Lovis, W. A. %A Urquhart, G. R. %A Raviele, M. E. %A J. P. Hart %K Alkali processing %K Bulk δ13C %K Hominy %K Maize histories %K Pottery residue %K Prehistoric cooking techniques %X

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.

%B Journal of Archaeological Science %V 38 %P 2726-2730 %G eng %U http://dx.doi.org/10.1016/j.jas.2011.06.010 %R 10.1016/j.jas.2011.06.010