Combining cosmogenic, stratigraphic, and paleomagnetic information using a Bayesian approach: General results and an application to Sterkfontein

In geochronology it is increasingly common to apply several methods to a set of samples. The task then arises of combining different types of data, with perhaps qualitatively different types of uncertainty, into a coherent age estimate which makes optimum use of the available information. In this paper we discuss a method which uses Bayesian reasoning to combine radiometric, stratigraphic, and paleomagnetic information when dating sediment layers. After presenting a general formulation, we derive an analytic formula for the probability distribution of the age of a sediment layer. We then apply this methodology to refine previous cosmogenic nuclide burial dating results for the age of a sediment layer containing a hominin fossil at Sterkfontein, South Africa.