Extended Data Fig. 2: Probability distributions of La-Ce closure ages.

La-Ce closure age probabilities for (a) the isochron fits as reported in the main text, (b) the same isochron fits for which ages are calculated using the upper 2 s uncertainty limits of the ¹³⁸La decay constants (see Methods), (c) isochron fits obtained if a student t-test expansion is applied to the analytical uncertainty determined in our study for the ¹³⁸La/¹³⁸Ce ratios, and (d) isochron fits for the case where 2 s uncertainties on the ¹³⁸La/¹³⁸Ce ratios are expanded artificially from 3.85% to 10% (see Supplementary Information). For (d), the joint probability of all three La-Ce closure ages versus time (dotted line) is provided on the second y-axis, demonstrating that even if analytical uncertainties were underestimated in this study, the joint probability that all three La-Ce isochrons may represent oxidation that occurred during the GOE is effectively excluded. The minimum depositional ages for each site as determined by zircon U-Pb geochronology are presented as vertical bars, with the width of each bar representing the 2 s uncertainty; in the case of Steep Rock, the uncertainty on the U-Pb minimum depositional age has been artificially expanded by a factor of 4 for visibility. See Supplementary Information for additional details.