Molybdenum and total organic carbon data from black shales is used to gain insights into the redox state of the ocean. The data suggests mild oxidative weathering of the continents before ∼2,200 Myr ago, but weathering becomes more persistent and vigorous at ∼2,150 Myr ago, 200 million years after the initial rise in atmospheric oxygen. Limited availability of molybdenum after 1,800 Myr ago may have acted as a negative nutrient feedback limiting the spatial and temporal extent of sulphidic conditions.
- C. Scott
- T. W. Lyons
- A. D. Anbar
