MAGic: a Phanerozoic model for the geochemical cycling of major rock-forming components. Radiolarian palaeoecology and radiolarites: is the present the key to the past? Earth Sci.
Oceanic nickel depletion and a methanogen famine before the Great Oxidation Event. Was there really an Archean phosphate crisis? Science 315, 1234 (2007) The oxygenation of the atmosphere and oceans. The relative influences of nitrogen and phosphorus on oceanic primary production. Nutrient limitation of net primary production in marine ecosystems. Early animal evolution: emerging views from comparative biology and geology. The snowball Earth hypothesis: testing the limits of global change. Co-diagenesis of iron and phosphorus in hydrothermal sediments from the southern East Pacific Rise: implications for the evaluation of paleoseawater phosphate concentrations. The relationship between P/Fe and V/Fe ratios in hydrothermal precipitates and dissolved phosphate in seawater. Particle geochemistry in the Rainbow hydrothermal plume, Mid-Atlantic Ridge. Ocean productivity before about 1.9 Gyr ago limited by phosphorus adsorption onto iron oxides. The Chemical Evolution of the Atmosphere and Oceans 598 (Princeton Univ. We propose that these two factors are intimately linked a glacially induced nutrient surplus could have led to an increase in atmospheric oxygen, paving the way for the rise of metazoan life.
The snowball Earth glaciations and Neoproterozoic oxidation are both suggested as triggers for the evolution and radiation of metazoans 6, 7. An enhanced postglacial phosphate flux would have caused high rates of primary productivity and organic carbon burial and a transition to more oxidizing conditions in the ocean and atmosphere. Specifically, there is a peak in phosphorus-to-iron ratios in Neoproterozoic iron formations dating from ∼750 to ∼635 Myr ago, indicating unusually high dissolved phosphate concentrations in the aftermath of widespread, low-latitude ‘snowball Earth’ glaciations. In contrast, phosphate concentrations seem to have been elevated in Precambrian oceans. The data suggest that phosphate concentrations have been relatively constant over the Phanerozoic eon, the past 542 million years (Myr) of Earth’s history. Here we present iron and phosphorus concentration ratios from distal hydrothermal sediments and iron formations through time to study the evolution of the marine phosphate reservoir.
The ratio of phosphorus to iron in iron-oxide-rich sedimentary rocks can be used to track dissolved phosphate concentrations if the dissolved silica concentration of sea water is estimated 2, 3, 4, 5.
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