ESR isochron dating for teeth: A brief demonstration in solving the external dose calculation problem

The radiation sensitive ESR signal at g = 2.0018 in fossil enamel can be used to date teeth absolutely, providing a suitable U uptake model can be selected, and the external dose rate, Dext, can be accurately calculated. Apart from the uptake model, the most obvious uncertainty lies in Dext. With the isochron method, Dext can be derived easily during the ESR analysis. By plotting the AD vs. the total internal dose rate for teeth where multiple subsamples have been analyzed, a regression line, the isochron, can be determined for each model age calculation. Each isochron slope represents the sample age, while its y-intercept gives the total external dose, Aext.