“…The presence of transient authigenic enrichments or isotopic fractionation of redox‐sensitive elements has been reported within Archaean‐aged rocks deposited up to 600–800 Myr prior to the GOE amidst a backdrop of evidence for an otherwise anoxic atmosphere (e.g. Anbar et al., ; Crowe et al., ; Eroglu, Schoenberg, Wille, Beukes, & Taubald, ; Frei, Gaucher, Poulton, & Canfield, ; Kurzweil, Wille, Schoenberg, Taubald, & Van Kranendonk, ; Olson, Kump, & Kasting, ; Reinhard, Raiswell, Scott, Anbar, & Lyons, ; Riding, Fralick, & Liang, ; Satkoski, Beukes, Li, Beard, & Johnson, ; Wille et al., ). Some of these signatures are attributed to localised oxygenation in restricted shallow marine oxygen “oases,” whereas others call for atmospheric O 2 in terrestrial environments at levels high enough to oxidise reduced minerals (e.g.…”