Bayesian Analysis of 210Pb Dating

In studies of environmental change of the past few centuries, Pb dating is often used to obtain chronologies for sedimentary sequences. One of the most commonly used approaches to estimate the age of material at different depths in a sequence is to assume a constant rate of supply (CRS) or influx of 'unsupported' Pb from the atmosphere, together with a constant or varying amount of 'supported' Pb. Current Pb dating models do not use a proper statistical framework and provide poor estimates of the uncertainties. Here, we develop a new model for Pb dating, where ages and values of supported and unsupported Pb form part of the parameters. We apply our model to a case study from Canada as well as to some simulated examples. Our model can extend beyond the current CRS approach, deal with asymmetric errors and mix Pb with other types of dating, thus obtaining more robust, realistic and statistically better defined age estimates.