Kiel diagram with the stars divided into the different stellar populations. The symbols are color-coded according to metallicity as indicated in the scale on the right side. The symbol size is proportional to the stellar age. Stars belonging to Gaia-Enceladus are highlighted by dark contours and have age precision better than 1.2 Gyr. Stars belonging to the Splash and Erebus have age precision better than 1.5 Gyr and 2.0 Gyr, respectively. Isochrones are overplotted for reference. The isochrone corresponding to the youngest Gaia-Enceladus population discussed in Sect. 7 is highlighted in red. These stars are the same shown in Figs. 7 and 8.