(Table 2) Surface exposure ages of samples near the head of Reedy Glacier

Be-10 concentrations are based on Be isotopic measurements normalized to pre-2007 values of the KNSTD standard series. Multiply by 1.106 for values compatible with post-2007 normalization. See Nishiizumi et al. (2007, doi:10.1016/j.nimb.2007.01.297). Simple exposure ages assume a steady production rate; altitude corrections per Lal (1991, doi:10.1016/0012-821X(91)90220-C) as implemented in the CRONUS calculator (http://hess.ess.washington.edu/math/). Standard deviation = external errors including all known analytical and production rate contributions propagated at the ±1sigma level. Internal errors do not include contributions to uncertainty in the final exposure ages common to all samples, such as production rate and scaling errors. External errors should be used when comparing these ages to ages obtained with other dating methods. Internal errors should be used to assess the consistency of exposure ages at a given site. Range of exposure ages returned by the four paleomagnetically corrected production rate scaling methods implemented in the CRONUS calculator. As noted before, these ranges are appropriate for external comparisons with other dating methods, and should not be used to assess the internal consistency of ages from a given site.