Calcium isotope ratios (<sup>44</sup>Ca/<sup>42</sup>Ca) have shown promise as a milk dietary tracer. Previous studies have focused on bone but, due to homeostatic processes, δ<sup>44/42</sup>Ca values are highly variable. This has greatly complicated the identification of mammal milk consumption through bone analysis, resulting in a search for an alternative. This thesis describes controlled studies to assess the effects of milk consumption on δ<sup>44/42</sup>Ca values in bulk and sequential samples of dental enamel, using modern samples from Yorkshire, England, the Isle of Hoy, Scotland, and archaeological samples from Abu Hureyra, Syria. The samples from Yorkshire consisted of dental enamel, ewe milk, feed and bone. Dental enamel was sampled from the Hoy sheep. Milk and plants are the greatest contributors of calcium in the mammal diet. Feed and ewe milk samples confirmed that milk has lower δ<sup>44/42</sup>Ca values than plants in the diet, and with a common diet between ewes, uniform milk δ<sup>44/42</sup>Ca values are produced. Also, there is a significant difference between bulk molar enamel δ<sup>44/42</sup>Ca values between males and females, with males having higher values. Additionally, analysis of bulk and sequential samples of Hoy mature sheep molar enamel, although mass fractionation effects were small, produced δ<sup>44/42</sup>Ca values with a clear isotopic offset between the enamel likely formed during nursing, weaning and the full conversion to a plant diet. The δ<sup>44/42</sup>Ca values, once associated with dental development chronologies, led to the identification of a clear pattern of nursing and weaning in the enamel of the first and second molars of sheep with known dietary and weaning histories. The modern results were used to identify patterns of ancient nursing and weaning. Although evidence was insufficient to establish early weaning of the Abu Hureyra sheep, this research successfully established the potential of this approach for investigating milk production and consumption in the archaeological record.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:655101 |
| Date | January 2014 |
| Creators | Wright, Carrie Carlota |
| Contributors | Lee-Thorp, Julia; Hedges, Robert |
| Publisher | University of Oxford |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://ora.ox.ac.uk/objects/uuid:6f7d5179-594a-41c3-a06d-478a811b818a |
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