When was potassium argon dating first used constantine maroulis dating 2016
The uncertainties in the crucial K/K abundance ratio also need to be considered, because there is no agreement on it. The value of 0.011672±0.000041% determined in 1975 is still adopted, but the value of 0.011668±0.000008% determined in 2013 has yet to be recognized. Therefore, when all these factors are considered the total K decay half-life, the adopted value ultimately depends on deriving it by adjusting (that is, massaging) K-Ar and Ar-Ar ages to conform to U-Pb and Pb-Pb ages obtained from different minerals respectively in the same rocks. But many unprovable assumptions are also involved, not the least being that the radioisotope systems closed at the same time and subsequently remained closed. “Analysis of the Relative Decay Constants of Ar Method. K decay half-life, obtained by direct counting experiments and by comparing radioisotope ages derived from more than one dating method applied to the same rocks or minerals. The determinations since 1997 have converged with close agreement toward the total K decay half-life value of 1.2524±0.0064Byr. Furthermore, even this U-Pb “gold standard” has unresolved uncertainties due to the U decay constants being imprecisely known, and to measured variations of the U ratio in terrestrial rocks, ores, and minerals, and in meteorites. Both of these factors are so critical to the U-Pb method, as well as the additional factor of knowing the initial concentrations of the daughter and index isotopes, so it should not be used as a standard to determine other decay constants. “Decay Constant Errors in U-Pb Concordia-Intercept Ages.” Chemical Geology 166 (3–4): 315–318.
There is also evidence decay rates of the radioisotopes used for rock dating have not been constant in the past, as well as the possibility of a slight decline in the measured values of the total K decay half-life during the 78 years of determinations.
This only serves to emphasize that if the K-Ar and Ar-Ar dating methods have been calibrated against the U-Pb “gold standard” with all its attendant uncertainties, then they cannot be absolute, and therefore they cannot be used to reject the young-earth creationist timescale.