The evolution of the marine phosphate reservoir Journal Article


Authors: Planavsky, Noah J.; Rouxel, Olivier J.; Bekker, Andrey; Lalonde, Stefan V.; Konhauser, Kurt O.; Reinhard, Christopher T.; Lyons, Timothy W.
Article Title: The evolution of the marine phosphate reservoir
Abstract: Phosphorus is a biolimiting nutrient that has an important role in regulating the burial of organic matter and the redox state of the ocean-atmosphere system(1). 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(2-5). 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 data suggest that phosphate concentrations have been relatively constant over the Phanerozoic eon, the past 542 million years (Myr) of Earth's history. In contrast, phosphate concentrations seem to have been elevated in Precambrian oceans. 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. 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. The snowball Earth glaciations and Neoproterozoic oxidation are both suggested as triggers for the evolution and radiation of metazoans(6,7). 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.
Keywords: Multidisciplinary Sciences; Sediments; phosphorus; IRON; Oceans; depletion; SILICA CYCLE
Journal Title: Nature
Volume: 467
Issue: 7319
ISSN: 0028-0836
Publisher: Nature Publishing Group  
Publication Place: LONDON; MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
Date Published: 2010-01-01
Start Page: 1088
End Page: 1090
Language: English
DOI/URL:
Notes: PT: J; NR: 30; TC: 1; J9: NATURE; PG: 3; GA: 671XW