Nor can the measured Pb isotope ratios be used to somehow decide what proportions of them are the initial Pb without recourse to unprovable assumptions about the mineral or rock’s history or their interpreted U-Th-Pb ages within an assumed deep time history.
The absolute ages provided by the radioisotope dating methods provide an apparent aura of certainty to the claimed millions and billions of years for formation of the earth’s rocks.
Many in both the scientific community and the general public around the world thus remain convinced of the earth’s claimed great antiquity.
One crucial area the RATE project did not touch on was the issue of how reliable are the determinations of the radioisotope decay rates, which are so crucial for calibrating these dating “clocks.” However, in a recent series of papers, Snelling (2014a, b, 2015a, b, 2016, 2017) reviewed how the half-lives of the parent radioisotopes used in long-age geological dating have been determined and collated all the determinations of them reported in the literature to discuss the accuracy of their currently accepted values.
He documented the methodology behind and history of determining the decay constants and half-lives of the parent radioisotopes U which are used as the basis for the Rb-Sr, Lu-Hf, Re-Os, Sm-Nd, K-Ar, Ar-Ar, U-Pb, and Pb-Pb long-age dating methods respectively.
However, even uncertainties of only 1% in the half-lives lead to very significant discrepancies in the derived radioisotope ages.
The recognition of an urgent need to improve the situation is not new (for example, Min et al. It continues to be mentioned, at one time or another, by every group active in geo- or cosmochronology (Boehnke and Harrison 2014; Schmitz 2012).He showed that there is still some uncertainty in what the values for these measures of the Rb decay rate differ when Rb-Sr ages are calibrated against the U-Pb ages of either the same terrestrial minerals and rocks or the same meteorites and lunar rocks.Ironically it is the slow decay rates of isotopes such as Sm used for deep time dating that makes precise measurements of their decay rates so difficult.However, problems remain in the interpretation of the measured Pb isotopic ratios to transform them into ages.Among them is the presence of non-radiogenic Pb of unknown composition, often referred to as common or initial Pb.U decay in those rocks added daughter Pb isotopes to the common or initial Pb isotopes in them, inherited from the rock’s sources.