Top left panel: age versus [Fe/H] for different radii, resulting from our input chemical model. Top middle panel: stellar density contours of the resulting relation after fusing with dynamics, for the “solar” radius (7 < r < 9 kpc). The overlaid curves indicate the input chemistry for some of the radii shown in the left panel. The pink dashed curve plots the mean, seen to closely follow the input r₀ = 8 kpc line (cyan). Top right panel: the metallicity distributions for different age bins. Bottom row: same as above, but for the [Fe/H]–[O/Fe] relation.