Mean [Mg/Fe] abundance vs. mean metallicity, ⟨[Mg/Fe]⟩−⟨[Fe/H]⟩, for the merger debris (filled symbols) and surviving satellites (empty symbols). In both panels, the symbols are colour-coded according to the total stellar mass. The left panel, similarly to Fig. 1, shows the relation for the SNd-like selection, while the right panel shows the values averaged over the entire system.