Position in the T_eff – log g plane of the GES targets in the direction of the CoRoT center and anti-center fields that were analyzed in iDR4, colored according to their [Fe/H]. The GES iDR4 analysis is not the final result because the GES-CoRoT project is still ongoing (see text for more details). The whole GES iDR4 sample is reported in the background as smaller gray squares.