(Top panel) Distribution of measured ionic column densities N_ion in the GRS 1915+105 outflow of observations 23435+24663, each plotted at its ξ of maximal formation. This outlines the overall distribution of N_H with ξ, showing a gradual increase, and then a turnover. The dashed lines represent the local slopes from H-like and He-like ion pairs, which are used to reconstruct the continuous AMD (see text), plotted in the bottom panel. Since there is no H in the spectrum, f_ion(ξ) and A_Z of H-like Fe are used to scale the absolute AMD values in terms of N_H (Equation (3)).