A burning question

Thesis

Cremated bone occurs in many archaeological sites as small grey and white fragments. The high temperatures reached during heating induce structural, chemical and isotopic changes to bone apatite (the inorganic fraction of bone). These changes are investigated here by infrared spectroscopy and mass spectrometry (δ¹³C, δ¹⁸O and ⁸⁷Sr/⁸⁶Sr) in both modern heated bone and archaeological cremated specimens. The results of various heating experiments (in laboratory and natural conditions) highlight the significant carbon and oxygen exchanges with the fuel used as well as with bone organic matter (mainly collagen). While not informing on dietary practice and hydrology as is the case with unburned bone, the δ¹³C and δ¹⁸O values of calcined samples together with infrared results provide information on the conditions in which the bone was heated (e.g. presence of fuel, size of the pyre, temperatures reached, dry or fresh bone, etc.). In parallel, the effect of heat on the strontium present in bone is minimal, if not undetectable. Furthermore, as observed through artificial contamination experiments, post-burial alterations also appear to be extremely limited, which is to be expected due to the higher crystallinity of calcined bone apatite compared to tooth enamel and unburned bone. These experiments demonstrate that calcined bone provides a reliable substrate for mobility studies using its strontium isotope composition. The application of these results to the study of six Neolithic and one Bronze Age sites from Ireland showed the possibility of discriminating cremated individuals that ate food originating from different regions, as well as highlighting possible variations in cremation practices between different sites. The results of this thesis greatly extend the application of strontium isotopes to places and periods in which cremation was the dominant mortuary practice, or where unburned bone and enamel do not survive. They also provide insights into the reconstruction of ancient cremation practices.

Authors: Snoeck, C

• Alternative title: structural and isotopic studies of cremated bone in archaeological contexts
• DOI: 10.5287/ora-8gy0jdqby
• Type of award: DPhil
• Level of award: Doctoral
• Awarding institution: University of Oxford
• Language: English
• Keywords: Cremation; Radiocarbon; Isotopes