Comparison between model predictions of magnesium (Minchev et al. 2013, 2014) and observations for clusters younger than 1.5 Gyr. The red and the blue lines are simulations from the MCM models for |z|< 0.3 kpc and 0.3 <  |z|< 0.8 kpc respectively. The color in the symbol indicates the distance from the Galactic midplane. All clusters are within 0.6 kpc from the Galactic plane, and SPA clusters are all within 0.5 kpc. The open “diamond” in the first panel is ASCC 123 (Frasca et al. 2019) and the “triangle” symbol in the 0.3−0.6 Gyr range is NGC 2632 (D’Orazi et al. 2020), for clusters between 1.5 and 4.5 Gyr. Only one SPA cluster is older than 4 Gyr: Ruprecth 171, from Casali et al. (2020).