Extended Data Fig. 1: La-Ce isotope data evaluated with respect to theoretical evolution from CHUR and as a function of Ce concentrations.

(a) ¹³⁸La-¹³⁸Ce isotope systematics of the combined dataset from the three studied Archean carbonate platforms, superimposed on the theoretical ¹³⁸La-¹³⁸Ce evolution trajectories drawn for 0.1 Ga, 1 Ga, 2 Ga, and 3 Ga from a CHUR-like initial precursor. For clarity, data points are enlarged relative to the measured analytical uncertainties. (b) Plots of measured Ce isotope compositions and (c) initial Ce isotope composition versus 1/Ce concentrations (in ppm) reveal no systematic correlations that might indicate that the reported isochrons are the result of disturbance or mixing of different Ce sources.