Carbon, oxygen, magnesium, and silicon abundances for the stars in the GALAH sample (Buder et al. 2018). Black dots mark the data from the detailed survey of Bensby et al. (2014), which does not include carbon. This plot illustrates that the trends of the GALAH survey agree with previous studies and that there is some variations within the sample. The black vertical lines at [Fe/H] = −0.45 and 0.45 indicate the [Fe/H] span used in Fig. 1, while the lines at [Fe/H] = 0 and [X/H] = 0 mark the solar value.