Stability of the nitrogen cycle in the redox-stratified late Paleoproterozoic Ocean

Posted By News On July 28, 2013 - 4:44pm

Around 1,840 million years ago, a widespread transition to euxinia occurred along productive continental margins.

Anoxic sulfidic conditions extended outward from near-shore to the mid-shelf, and were overlain by oxic surface waters and underlain by anoxic and Fe-rich (ferruginous) water maintaining the redox stratification of the ocean, which developed with the evolution of oxygenic photosynthesis. Widespread sulfidic conditions throughout the Mesoproterozoic have been implicated in the protracted oxygenation of the atmosphere and slow rates of eukaryotic evolution. However, the continuation of ferruginous deep water conditions through the Mesoproterozoic, with sulfidic conditions limited to areas of high organic carbon production, highlights that the controls on productivity, and oxygenic productivity in particular, remain poorly understood.

Linda Godfrey and colleagues report new nitrogen and carbon isotope data for sediments from six drill cores that provide a 350-km-long oblique transect to the paleo-coastline of the Animikie Basin on the margin of Superior Province, North America.

Linda V. Godfrey et al., DOI: 10.1130/G33930.1.

Post new comment

The content of this field is kept private and will not be shown publicly.
  • Allowed HTML tags: <em> <strong> <cite><p><br><i><b><center><ul><li><div><html5:figure><html5:figcaption>
  • Lines and paragraphs break automatically.

More information about formatting options

CAPTCHA
Sorry, we know you're not a spambot, but they're out there