Left column: overlaid normalized metallicity distributions for different distances from the Galactic center for stars with | z | < 0.5 kpc (top) and 0.5 < | z | < 3 kpc (bottom). This shows that variations in the metal-rich end seen in Fig. 7 come mostly from stars close to the disk midplane. Right column: as on the left but for [Mg/Fe]. Similarly to [Fe/H], strong variations with radius are seen mostly for stars close to the disk midplane. The reason for this is that migrating stars stay with cool kinematics (both in the radial and vertical directions), i.e., do not contribute to thick disk formation.