Figure 20. Plot showing the same data and lowest RMSE model fit for Sands of Forvie as shown in Figure 18, together with the SSA spectra for endmembers used to model the data. The weight abundances and grain sizes are provided in the caption on the plot.
Violin plots for model runs discussed above are shown in Figure 21 for the two endmember spectra. Only model runs with RMSE ≤ 0.005 and R2 ≥ 0.96 are included in the violin plots, which amounts to 83 model runs using the MDI deposit endmember spectrum and 46 model results using the SoF deposit endmember spectrum. These plots show a wide range of results, as expected from the nonunique nature of the model. We do note that the trends in the data follow what we described for the two best fits. This leads us to conclude that the GMS glass and labradorite are the most abundant phases and primarily responsible for controlling the overall albedo of the MDI and SoF spectral endmembers. Spectral differences at longer wavelengths are likely controlled by the relative proportions of the two pyroxenes in each deposit. Further, the grain sizes are generally larger for the SoF as opposed to the MDI deposits.