An Improved Geochemical Model of Atmospheric CO2 Fluctuations Over the Past 100 Million Years

  1. E.T. Sundquist and
  2. W.S. Broecker
  1. Antonio C. Lasaga1,
  2. Robert A. Berner2 and
  3. Robert M. Garrels3

Published Online: 18 MAR 2013

DOI: 10.1029/GM032p0397

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

Lasaga, A. C., Berner, R. A. and Garrels, R. M. (2013) An Improved Geochemical Model of Atmospheric CO2 Fluctuations Over the Past 100 Million Years, 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/GM032p0397

Author Information

  1. 1

    Department of Geosciences, the Pennsylvania State University, University Park, Pennsylvania 16802

  2. 2

    Kline Geology Laboratory, Yale University, New Haven, Connecticut 06511

  3. 3

    Department of Marine Science, University of South Florida, St. Petersburg, Florida 33701

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

The carbonate-silicate geochemical cycle of Berner, Lasaga and Garrels [Berner et al., 1983] is extended to include reactions involving organic carbon and sulfur. To study the effect of the extended cycle on atmospheric CO2, new reservoirs are added for organic carbon, pyrite, gypsum, and atmospheric oxygen. The present-day cycle is constructed taking into account oxidation of pyrite, diagenetic pyrite formation, sulfate reduction at mid-ocean ridges, organic carbon weathering and organic carbon burial, in addition to the fluxes included by Berner et al. [1983]. The organic carbon and reduced sulfur fluxes over the last 100 million years are obtained from a generalized isotope model and data on δ13C and δ34S. The augmented model modifies the results of BLAG, Berner et al. [1983], while retaining the basic conclusions, specifically the link between CO2, paleoclimate, and tectonism.