Biogenic Apatite (CaPO4) Analysis

Biogenic materials track a host of environmental and physiological parameters and allow for both subtle and complex inferences about the processes that form them. Preservation of most biogenic materials in the fossil record is poor especially in older samples but the best preserved and some of the most extensive records are biological apatites (bioapatites). The most important of these to the geological record are bone, dentin, and enamel which are fortuitously amongst the most widely collected and curated sample types. The principal component of these bioapatites is calcium phosphate (CaPO4), along with associated carbonates, silicates and hydroxides as minor components. These bioapatites are a common locus for a suite of geochemical measurements studying both the phosphate and carbonate components and while there are many fascinating isotopic systems to study in bioapatites, the most useful in the context of geochemical and archaeological studies, is the the oxygen isotopic signature (δ18O). Within bone and tooth samples (especially within thermoregulating terrestrial vertebrates), δ18O is profoundly influenced by the global meteorologic cycle and as such provides a powerful tool to study climate variability and an organism’s interaction with their environment.

Archaeology, Paleontology & Paleoclimatology

CaPO4 oxygen isotopes in human and other organism bones and teeth can provide a signal of:

  • Seasonal and annual precipitation
  • Altitude
  • Significant weather events
  • Humidity
  • Migration
  • Thermoregulation
  • Growth rate
  • Drought resistance/susceptibility and preference for C3 vs. C4 plants in diet
  • Diagenesis
  • Even tectonics!

Sample types available for CaPO4 analysis: Bones & teeth

Sample Size: 30 mg

Reported as δ18O VSMOW, with uncertainties for each sample measurement presented as the 95% confidence interval (CI).

Note: This service has been discontinued starting January 2024.