Left: overlaid normalized metallicity distributions at different distances from the Galactic center (all solid-black histograms in bottom row of Fig. 5). The peak of the total distribution for each radial bin is always centered on [Fe/H] ≈ −0.15 ± 0.06 dex and the metal-poor wings are nearly identical, extending to [Fe/H] ≈ −1.3 dex. In contrast, the metal-rich tail of the distribution decreases with increasing radius, giving rise to the expected decrease in mean metallicity with radius. Right: as on the left but for [Mg/Fe]. Similarly to [Fe/H], the peak does not vary significantly as a function of Galactic radius, being situated at [Mg/Fe] ≈ 0.15 ± 0.08 dex. Unlike the metallicity distribution, the α-poor tail is lost as radius increases, while the α-rich tail always ends at [Mg/Fe] ≈ 0.45 dex. However, the correspondence between [Fe/H] and [Mg/Fe] is not symmetric: for [Mg/Fe] both wings of the distribution are affected and the width decreases with increasing radius. See Fig. 9 for variation with distance from the disk plane.