Extended Data Fig. 4: Comparison of N concentrations with K2O concentrations of the studied BIF samples.
From: A seawater oxygen oscillation recorded by iron formations prior to the Great Oxidation Event

Note that the two samples with exceptional high Al2O3 contents (>2 wt.%) are not included. 2σ error bars of the data are smaller than the symbols and thus not shown. WWF = Weeli Wolli Formation; JM = Joffre Member; DGM = Dales Gorge Member; MMF = Marra Mamba Formation.