Run of [Na/Fe] and α-element abundance ratios ([Ti/Fe], [Ca/Fe], [Si/Fe], [Mg/Fe] from top to bottom) versus [Fe/H] for E3 (filled red squares) and Galactic stars. The large black open circle with error bars indicates the mean cluster abundance and Gaussian dispersion. Gray filled circles are halo stars from Gratton et al. (2003, their dissipative component) and Venn et al. (2004, halo probability greater than 0.8). Open magenta triangles are thick disk stars from Reddy et al. (2006), while cyan crosses are thin disk stars from Reddy et al. (2003).