Relationships between [Fe/H], the α elements (including [α/Fe] defined as the average of Mg, Ca, Si, and Ti indexed against Fe), Na, and Al, colored by log (Age) and sized by R_gc; the larger one is the sample with the longer R_gc. The small dots are for the HARPS-GTO samples. The O abundances are not available for the HARPS-GTO sample. The relationships between [Fe/H] and [Na/Fe] and [Al/Fe] are colored by log (Age). The small dots are for the HARPS-GTO samples.