SYSTEMATIC DIFFERENCES BETWEEN U-PB AND 40AR/39AR DATES: REASONS AND EVALUATION TECHNIQUES

Abstract

Progress recently achieved in the development of mass spectrometric equipment made it possible to significantly improve the accuracy of radioisotopic dating. For example, the errors of U–Pb and 40Ar/39Ar dates quoted in various publications are often 0.1–0.2% of the age values or, sometimes, even lower. However, these errors are purely analytical and do not involve the uncertainties in the decay constants of the parent isotopes. The errors of the decay constants are systematic when age values obtained by the same techniques are compared, and, thus, these errors can be neglected.