Burning and boiling of modern deer bone: Effects on crystallinity and oxygen isotope composition of bioapatite phosphate

• Published in: Palaeogeography, palaeoclimatology, palaeoecology palaeoclimatology, palaeoecology, 2007-06, Vol.249 (1), p.90-102
• Main Authors: Munro, L.E., Longstaffe, F.J., White, C.D.
• Format: Article
• Language: English
• Subjects: Bioapatite; Diagenesis; Heating; Odocoileus virginianus; Recrystallization; Stable isotopes
• ISSN: 0031-0182; 1872-616X
• DOI: 10.1016/j.palaeo.2007.01.011

The extent of preservation of stable isotope compositions in biomaterials exposed to burial and weathering continues to be a topic of some debate. Changes in the isotopic composition of archaeological bones and teeth during recrystallization are often suspected, but difficult to prove. Here, we examined the effects of heating (burning, boiling) on the isotopic composition of phosphate oxygen ( δ 18O p) in bone bioapatite from two modern White-Tailed deer ( Odocoileus virginianus). Our experiments simulated cooking and refuse disposal practices, which have affected many archaeological samples. Original values for δ 18O p were preserved at < 300 °C. At higher temperatures, values were lowered by as much as 7‰ from primary compositions. Only small changes in crystallinity (measured using FTIR and XRD) were observed from 25 to 675 °C, despite large shifts in δ 18O p above 300 °C. Original values for δ 18O p were preserved only at FTIR CI ≤ 2.5–2.7. XRD CI values were not sensitive to changes in δ 18O p below ∼ 625 °C.