17 18 All samples except 502067 and 406042 19 Each sample
20ic, and hand picking techniques at the University of Houston. Analyzed muscovite grains 21 passed through a 60 mesh 250 μm sieve but were retained in an 80 mesh 177 μm sieve. For 22 convenience, in the main text we refer to this grain size as approximately 200 μm. Our samples 23 were separated, irradiated, and analyzed as part of a batch that included the samples discussed in



































