[Fe/H], [Mg/H], and [Mg/Fe] at a fixed stellar mass (M _* = 10¹¹ M _⊙) as a function of formation time for the LEGA-C (gray circles), Heavy Metal (blue triangles and green stars), SDSS (black diamonds), and various other z > 1 studies (refer to the legend in Figure 2). Abundances at fixed stellar mass are calculated from the M _*–abundance relations at z ∼ 0 shown in Figure 4. We assess the strength of the correlation between the elemental abundances and formation time using the Pearson correlation test (results listed in each panel). Galaxies that form at later cosmic epochs have higher [Fe/H] and [Mg/H] and slightly lower [Mg/Fe]. At a fixed t _form, the Heavy Metal galaxies exhibit similar abundances to the SDSS and LEGA-C populations.