Top panel: the general [α/Fe] vs. age distribution for stars in the sample, for all stars having an absolute magnitude M_v < 4.75. Open circles indicate stars which have alpha enhancements consistent with the thick disk but have ages indicative of the thin disk and also lie on the thick disk sequence in the [α/Fe]–[Fe/H] plane. The line divides the thick and thin disk populations. Bottom panel: same stars, the color coding the absolute magnitude of stars is described by the vertical scale.