Organic Carbon Preservation in Marine Sediments

  1. E.T. Sundquist and
  2. W.S. Broecker
  1. Steven Emerson

Published Online: 18 MAR 2013

DOI: 10.1029/GM032p0078

The Carbon Cycle and Atmospheric CO: Natural Variations Archean to Present

The Carbon Cycle and Atmospheric CO: Natural Variations Archean to Present

How to Cite

Emerson, S. (1985) Organic Carbon Preservation in Marine Sediments, in The Carbon Cycle and Atmospheric CO: Natural Variations Archean to Present (eds E.T. Sundquist and W.S. Broecker), American Geophysical Union, Washington, D. C.. doi: 10.1029/GM032p0078

Author Information

  1. School of Oceanography, University of Washington, Seattle, Washington 98195

Publication History

  1. Published Online: 18 MAR 2013
  2. Published Print: 1 JAN 1985

ISBN Information

Print ISBN: 9780875900605

Online ISBN: 9781118664322

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Keywords:

  • Carbon cycle (Biogeochemistry)—Congresses;
  • Atmospheric carbon dioxide—Congresses;
  • Geological time—Congresses;
  • Paleothermometry—Congresses;
  • Geology, Stratigraphic—Congresses

Summary

Mechanisms that control the preservation of organic carbon in the ocean are the key to interpreting the paleoceanographic carbon signal. This process is investigated here utilizing published data from sediment trap experiments in a model that couples organic carbon and oxygen reactions in marine sediments. The carbon content of sediments is most strongly influenced by the particulate organic carbon flux to the bottom, the bottom water oxygen content, and the organic matter degradation rate constant. The familiar correlation between sediment organic carbon content and sedimentation rate is likely a result of the direct relationship between the total particulate flux and organic carbon flux rather than a preservation effect of rapid sedimentation. The data indicate that the degradation rate “constant” for organic material oxidation in marine sediments increases with increasing particulate organic carbon flux to the bottom. The positive correlation of these parameters enhances the relative importance of the bottom water oxygen concentration to organic matter preservation. Cycles of the carbon concentration over the past 100,000 years in marine sediments may be influenced by changes in bottom oxygen concentration. Recent arguments that organic carbon burial on the continental slope is an effective sink for anthropogenic fossil fuel CO2 require 50% of the particulate algal carbon raining from the photic zone of the continental shelves to escape degradation and undergo burial. Calculations presented here suggest that the organic matter degradation rate is much too rapid for this amount to be buried and that the potential sink is overestimated by roughly a factor of 5.