Figure 3: Linking nuclide concentrations to exposure history.

(a) Plot of ²⁶Al/¹⁰Be ratio against ¹⁰Be concentration for all samples used in the MCMC-based quantification of complex exposure histories. The upper black line marks the development of the ratio under constant exposure and the lower black line marks the end points of an infinite number of different steady-state erosion rate scenarios with constant exposure. Error bars are based on uncertainties of the ²⁶Al and ¹⁰Be concentrations. (b) Sample altitude plotted against percentage of time exposed over the last 1 Myr for each sample. (c) Plot of ²⁶Al/¹⁰Be ratio against percentage of time exposed over the last 1 Myr for each sample. There is a clear correlation between ²⁶Al/¹⁰Be ratios and the percentage of exposure over the last 1 Myr based on the MCMC-modelled exposure history. The horizontal dashed line marks the production ratio of ²⁶Al/¹⁰Be and the vertical dashed line marks 87% of exposure in 1 Myr, which corresponds to 15 kyr of ice cover during the LGM. Error bars are defined as the first and third quartiles of the 200,000 iterations per sample.