Reexamination of 2.5-Ga "whiff" of oxygen interval points to anoxic ocean before GOE

Sarah P. Slotznick, Jena E. Johnson, Birger Rasmussen, Timothy D. Raub, Samuel M. Webb, Jian Wei Zi, Joseph L. Kirschvink, Woodward W. Fischer

Research output: Contribution to journalArticlepeer-review

37 Citations (Scopus)


Transient appearances of oxygen have been inferred before the Great Oxygenation Event (GOE) [∼2.3 billion years (Ga) ago] based on redox-sensitive elements such as Mo and S-most prominently from the ∼2.5-Ga Mount McRae Shale in Western Australia. We present new spatially resolved data including synchrotron-based x-ray spectroscopy and secondary ion mass spectrometry to characterize the petrogenesis of the Mount McRae Shale. Sediments were primarily composed of organic matter and volcanic ash (a potential source of Mo), with U-Pb ages revealing extremely low sedimentation rates. Catagenesis created bedding-parallel microfractures, which subsequently acted as fluid pathways for metasomatic alteration and recent oxidative weathering. Our collective observations suggest that the bulk chemical datasets pointing toward a "whiff"of oxygen developed during postdepositional events. Nonzero Δ33S in trace-metal-poor, early diagenetic pyrite and the unusually enriched organic carbon at low sedimentation rates instead suggest that environmental oxygen levels were negligible ∼150 million years before the GOE.

Original languageEnglish
Article numberabj7190
Number of pages10
JournalScience Advances
Issue number1
Publication statusPublished - 5 Jan 2022


Dive into the research topics of 'Reexamination of 2.5-Ga "whiff" of oxygen interval points to anoxic ocean before GOE'. Together they form a unique fingerprint.

Cite this