A02_P06

Estimating freshwater reservoir ages using Bayesian models for the Mesolithic to neolithic transition

Olsen J¹, Maaring R¹, Mannino M¹

¹Aarhus University, Aarhus, Denmark

The chronology of the Mesolithic to Neolithic transition is difficult to date accurately using radiocarbon analysis on human or animal bone remains. This is because that in particular the hunter-gather culture of the Mesolithic involves diets from multiple sources. When both marine and freshwater food webs are exploited, it becomes difficult to correct the radiocarbon ages for possible reservoir effects. In particular, the freshwater reservoir effect is unknown and expected to vary substantially. We have collected a large dataset of dog bones across the Mesolithic to Neolithic transition from which we have deduced the percentage of terrestrial, marine and freshwater diets using a FRUITS model. Further, we have included a dataset of domesticated cattle. All from multiple sites across Denmark. We have constructed a Bayesian model with phases based on the archaeological typology, i.e. belonging to either Mesolithic or Mesolithic. In the model we have allowed for estimating the total reservoir age using a wide uniform prior. If we assume that the marine reservoir age is known then the freshwater reservoir age can be estimated from the posterior total reservoir age probability distribution. The calculated freshwater reservoir age vary from a few hundred ¹⁴C years and up 1200 ¹⁴C years. Further, we have tested the robustness using different Bayesian model of the Mesolithic to Neolithic transition and found our freshwater reservoir estimates are similar and independent of model choice.