Intercalibration of U-Pb and Ar-Ar chronometers -- 238U and 235U decay constants, and the electron capture and beta- 40K decay constants, and the eruption age (more precisely, kappa = 40Ar*/40K) of the Fish Canyon tuff.

First pass: weighted least squares, Renne et al. (2010-2011) data to start. These comprise

1. Jaffey et al. (1971) measurements of the 238U and 235U decay constants
2. Several measurements of kappaFCs
3. Min et al. (2000) value of beta 40K decay constant, compiled and re-calculated from literature
4. Min et al. (2000) value for electron capture 40K decay constant, compiled and re-calculated from literature
5. Total 40K decay constant from liquid scintillation counting of 40K (see Renne et al. 2011 reply)
6. U/Pb - Ar/Ar data pairs, starting with Table 2 of Renne et al. (2010-2011).
7. U-Pb and/or Ar-Ar dates with independent constraints (historical eruptions like Vesuvius or astrochronologically tuned).