L. E. Nyquist

TL;DR: The decay constants used in geo- and cosmochronology usually are assigned uncertainties of ca. 1% but there are very much larger unaccounted discrepancies between decay constants reported by different "counting groups" as well as differences between results derived from counting experiments and from the comparison of ages obtained on the same samples by utilizing different radioactive clocks.

TL;DR: In this article, isotope dilution data of the shergottite meteorite QUE 94201 has been used to identify a leachable crustal component in the meteorite, which can affect the isochrons by selectively altering the isotopic systematics of the leachates and some of the mineral fractions.

TL;DR: In this paper, a crystallization age of 474 ± 11 Ma and an initial eNd143 value of +36.6 ± 0.8 were derived from a source region that had a slightly greater incompatible enrichment than the QUE94201 source region.

TL;DR: The carbonate formation age is contemporaneous with a period in martian history when the surface is thought to have had flowing water, but also was undergoing heavy bombardment by meteorites, therefore, this age does not distinguish between aqueous and impact origins for the carbonates.

TL;DR: In this article, Neodymium, stontium, and chromium isotopic studies of the LEW86010 angrite were conducted to establish its absolute age and the formation interval between its crystallization and condensation of Allende CAIs from the solar nebula.