Geochemical evidence for suppression of pelagic marine productivity at the Cretaceous/Tertiary boundary

  title={Geochemical evidence for suppression of pelagic marine productivity at the Cretaceous/Tertiary boundary},
  author={James C. Zachos and Michael A. Arthur and Walter E. Dean},
The normal, biologically productive ocean is characterized by a gradient of the 13C/12C ratio from surface to deep waters. Here we present stable isotope data from planktonic and benthic micro-fossils across the Cretaceous/Tertiary boundary in the North pacific, which reveal a rapid and complete breakdown in this biologically mediated gradient. The fluxes of barium (a proxy for organic carbon) and CaCO3 also decrease significantly at the time of the major marine plankton extinctions. The… 

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