U pb dating of zircon
From a creationist perspective, the 1997–2005 RATE (Radioisotopes and the Age of The Earth) project successfully made progress in documenting some of the pitfalls in the radioisotope dating methods, and especially in demonstrating that radioisotope decay rates may not have always been constant at today’s measured rates (Vardiman, Snelling, and Chaffin 2000, 2005).
Yet much research effort remains to be done to make further inroads into not only uncovering the flaws intrinsic to these long-age dating methods, but towards a thorough understanding of radioisotopes and their decay during the earth’s history within a biblical creationist framework.
The stunning improvements in the performance of mass spectrometers during the past four or so decades, starting with the landmark paper by Wasserburg et al.
Subsequently new crustal rocks formed via partial melts from the mantle.
2001; Steiger and Jäger 1977), in spite of ongoing attempts (Miller 2012).
The uncertainties associated with direct half-life determinations are, in most cases, still at the 1% level, which is still significantly better than any radioisotope method for determining the ages of rock formations.
These new rocks rapidly accumulated more Pb isotopes due to the concurrent accelerated radioactive decay of U and Th in them during the Flood.
Thus, without being able to unequivocally distinguish the daughter Pb atoms produced by in situ U and Th decay from the initial Pb atoms in a mineral or rock, it is impossible to determine their absolute U-Pb ages.