Final clean GES dataset of 1725 stars in the [Mg/Fe] vs. [Fe/H] plane. A red dashed line marks the separation between α-rich and α-poor (thick and thin disks) estimated as the minimum of the [Mg/Fe] distributions in several intervals of metallicity (as made in Recio-Blanco et al.2014 and Mikolaitis et al.2014 in the [α/Fe] vs. [M/H] plane). The four panels around the central panel display the marginalized distributions in metallicity and Mg abundance corresponding to these two disk sequences. Bar histograms stand for the thick disk and step histograms for the thin disk. A p-value, derived from the Anderson-Darling test for Gaussianity, is quoted in each panel.