Fig. 3: Fo-δ18O covariations diagrams for olivine grains.

a Binary diagram of δ18O value and Fo content in olivine from the Weltevreden komatiites. Blue symbols represent low δ18O olivines from five samples; red symbols represent normal δ18O olivine from the other six samples. b Average δ18O values versus average Fo values in olivine from each sample. “Error bars” represent one standard deviation (1 SD) of δ18O and Fo content of olivines in each sample, respectively. There is no overlap of δ18O-Fo systematics between the two groups.