Time evolution of [M/H] (upper panel) and [α/Fe] (lower panel) ratios for the stellar sample presented by VSA18, compared with our chemical evolution model predictions (black solid line). Purple filled circles depict the high-α population, whereas green filled circles represent the low-α one. In the upper panel, light blue symbols indicate median age uncertainties for 3 and 11 Gyr old stars of the VSA18 sample.