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pg 127 There are three main areas in which chemcial analysis might be expected to yield useful information (Gilbert 1977): 1) the assessment of nutritional deficiencies 2) the assessment of the major components of, and chages in diet 3) the assessment of exposure to toxic elements of, and changes in, diet and health. pg 152 The knowledge that bones may take up elements over extremely long periods has, of course, been know for years and was used a means of relative dating of fossils
Oakley (1932) used the lead and zinc ontent of the fossil bones of "Rhodesian Man" as a means of deciding whether or not all the skeletal elements which were found were from a single individual. pg 155 It has been argued, therefore, that it might be possilbe to infer the composition of the diet from an analysis of the trace metals inthe skeleton. Toots and Voorhies (1965) were able to showthat pliocene herbivore bones contained more strontium than bones from carnivores, and Brown (1973) and Schoeninger (1979) suggested that this technique could be applied to infer the composition of the human diet. The distribution between herbivores and carnivores is by no means always absolute, however. Sillen (1981) found that bone strontium/calcium (Sr/Ca) ratios discriminate well between herbivores and carnivores from Natufian levels at Hayonim Cave but not between those in Aurignacian levels, and his assertion that the Sr/Ca technique has been shown effectively to distinguish between the diets of animal species is perhaps a little too optimistic with present knowledge. The Sr/Ca ratios of 14 natufian human bones fell between thsoe of the herbivores and carnivores which was tekn as evidence for an omnivorous diet. [Elias 1980 contradicts this however] pg 156 Sillen has more recently suggested a further use for strontium analysis (Sillen and Smith 1984), that is, for determining weaning patterns. ...there is almost a linear increase in the Sr/Ca ratios in the skeleton from birth to one year of age, followed by a more gradual increase to age two, after which, there is a decline to adult values by about age three. The author interpet this to imply that weaning to place between the ages of two and three.
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