The 10Be data set includes the geographic position and elevation of the analyzed samples and the detailed analytical results including the blank correction, the correction for geological inheritance, and the final 10Be concentrations (atoms/gram) used to calculate the 10Be exposure ages.

Comments:1) 10Be concentrations were measured at the Cologne AMS, Germany (Dewald et al., 2013), and are normalised to the standards KN01-6-2 and KN01-5-3 with nominal 10Be/9Be ratios of 5.349 x 10-13 and 6.320 x 10-12, respectively. We also analysed two aliquots of the quartz reference material CoQtz-N with a 10Be concentration of 2.53±0.09 × 106 at/g (Binnie et al., 2019), for which we obtained 10Be concentrations of 2.40±0.09 and 2.61±0.09 × 106 at/g, respectively. The uncertainties of the 10Be concentrations (1σ) include the analytical uncertainty and the error of the blank correction. The analytical uncertainty includes the error based on the counting statistics, the scatter of repeated measurements of the same sample, and the uncertainty of the standard normalisation. Note that the 10Be concentrations reported for the terrace samples were corrected for an inherited 10Be component of 20±10 x 104 at/g, based on the 10Be concentration of the amalgamated sample 16C28 from an active stream channel.2) 10Be exposure ages were calculated with the CRONUS-Earth 10Be – 26Al online calculators (http://hess.ess.washington.edu/, version 3), using the time-dependent scaling model of Lifton et al. (2014), referred to as LSDn in the online calculator. All ages were calculated assuming a rock density of 2.65 g cm-3 and zero erosion.