Rules for carbon dating radiocarbon dating belfast
Our approach was elaborated on known-age samples from the Fifth International radiocarbon Inter-comparison (VIRI) and served as proof of concept.
The method was then applied to two archaeological sites where the single bones of small mammals were AMS-dated, and the dates compared to standard-size bone samples found in the near vicinity.
While the exchange of inorganic carbon occurs much more readily, the relative chemical inertness of biopolymers makes them ideal for dating; therefore, the majority of bone radiocarbon dates are obtained from the collagen phase.
The chemical integrity of this biomolecule can be assessed using simple biochemical criteria such as %C, %N and C/N ratio.
In both studies, the bones were Late Pleistocene to Holocene in age, and weights were comprised of between 30–60 mg. However, ultrafiltration is often associated with lower extraction yields (especially when bones are moderately to poorly preserved), and does not always allow for the recovery of a sufficient amount of collagen when sample mass is lower than 100 mg. In general, the solution consists in dating a “reliably associated” artefact (often charcoal) from the same stratigraphic unit instead of the bone remains.In effect, they provide us with windows to past societies, and contribute to our knowledge of ancient human evolution and cultural development.Hard tissues contain an organic phase (mainly the protein collagen type I) embedded in a mineral phase (made of a non-stoichiometric biogenic apatite).The results obtained for the four known-age (VIRI) bone samples are summarized in Supplementary Table S1.The impact of sample size on the collagen extraction yield and the radiocarbon age are discussed below. In this figure, a normalized yield was calculated for clarity and to enable direct comparisons.