Use of Non-alkaline Earth Elements

The methodological misstep most responsible for this interpretive chaos began with the inclusion of elements other than strontium and barium. Although it required extensive research to reveal the bone-diet connection for strontium, this was reduced, evidently for simplicity, and not altogether without validity, to the idea that plants are higher in strontium, than is meat, and that bones reflect this dietary difference. Then with Gilbert s thesis suggesting that zinc apparently also reflects this, the concept as transcribed to 

Strontium, that of Toots and Voorhies (1965), used these compositional differences among plants to assess not the dietary plant/meat ratio but the degree of browsing versus grazing. It is this phenomenon due to shifting plants that we are likely to observe in comparative Sr/Ca studies of bone, rather than the amount of meat in the diet, simply because plants have a much greater impact on diet composition. 

This sensitivity to vegetation also appears in the data from our study of modem plants and animals. More than a thousand samples spanning a wide range of species of both plants and animals were selected from a five-county area in northeastern Wisconsin. While herbivores have significantly lower 

Although there are many failed attempts to determine even relative measures of meat eonsumption, the disappointment is not due to any failure of strontium to reflect diet but to an unwarranted expectation that bone strontium should necessarily reflect meat consumption. The frustration with efforts to draw paleodietary inferences stems from simplistically equating Sr/Ca ratios with plant/meat ratios and to the inappropriate use of elements not 

The examples discussed above suggest useful directions for future research involving trace element analysis of bones. Specifically, the effects of developmental age and other factors (e.g., porosity, mineralization) that may lead to differences in surface area of specimens should be considered. Diage-netic effects should be monitored by analysis of a suite of elements whose abundances are not controlled by dietary abundances (e.g., Mn, Zr, etc.). Finally, although alkaline elements such as Sr and Ba are most likely to reflect the Sr/Ca and Ba/Ca levels of the diet, omnivores such as humans are likely to obtain the majority of these elements from plants rather than from animals. Therefore for accmate diet reconstruction it is necessary to determine the total abundance of Ca as and the Sr/Ca and Ba/Ca ratios of the plant and animal resources that were potential dietary staples. The effects of culinary practices on elemental abundances (Burton and Wright 1995 Katzenberg et al. this volume) must also be evaluated. 

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