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Consistent CO2 release by pyrite oxidation on continental shelves prior to glacial terminations

This article has been updated


Previous evidence suggests enhanced pyrite oxidation on exposed continental shelves during glacial phases of low sea level. While pyrite oxidation directly consumes atmospheric oxygen, acid generated by this reaction should increase the release of CO2 through carbonate dissolution. This scenario represents a climate control loop that could temper or even prevent glacials because increasing CO2 triggers warming and rising sea level. However, the amplitudes of sea-level changes increased over the Quaternary, and CO2 concentrations co-varied with sea level throughout most of the past 800,000 years. Only during peak glacial conditions did CO2 levels reach an apparent lower threshold independent of falling sea level. Here we suggest that during the last nine glacial–interglacial cycles, pyrite-oxidation-driven release of CO2 and consumption of O2 occurred during 10 kyr to 40 kyr periods preceding glacial terminations. We demonstrate that repeated sea-level lowstands force pyrite oxidation to ever-greater depths in exposed shelf sediments and cause CO2 release that could explain the glacial CO2 threshold. When the duration of interglacials with high sea level is insufficient to restock the shelf pyrite inventory, this CO2-releasing process represents a discharging ‘acid capacitor’.

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Fig. 1: Sea levels and atmospheric CO2 during the past 800 kyr.
Fig. 2: Interglacial pyrite burial and glacial pyrite oxidation on continental shelves.
Fig. 3: Sea level, atmospheric CO2 and O2, and pyrite oxidation during the past 800 kyr.
Fig. 4: Sea level, obliquity, modelled pyrite oxidation rates and position of the pyrite oxidation front.

Data availability

The data created in this paper are available through, the original composite CO2 dataset16 is available through and the original sea-level dataset1 is available through

Code availability

The model code is available through

Change history

  • 03 December 2019

    The Supplementary Information data file ‘Reference run results’ has been updated to include the data contained in Figs. 1, 3 and 4 of the main text.


  1. 1.

    Bintanja, R. & van de Wal, R. S. W. North American ice-sheet dynamics and the onset of 100,000-year glacial cycles. Nature 454, 869–872 (2008).

    Google Scholar 

  2. 2.

    Berner, R. A. Burial of organic carbon and pyrite sulfur in the modern ocean: its geochemical and environmental significance. Am. J. Sci. 282, 451–473 (1982).

    Google Scholar 

  3. 3.

    Sinninghe Damsté, J. S., Rijpstra, W. I. C., Kock-van Dalen, A. C., De Leeuw, J. W. & Schenck, P. A. Quenching of labile functionalised lipids by inorganic sulphur species: evidence for the formation of sedimentary organic sulphur compounds at the early stages of diagenesis. Geochim. Cosmochim. Acta 53, 1343–1355 (1989).

    Google Scholar 

  4. 4.

    Jørgensen, B. B. & Kasten, S. in Marine Geochemistry (eds Schulz, H. D. & Zabel, M.) 271–309 (Springer-Verlag, 2006).

  5. 5.

    Blowes, D. W., Ptacek, C. J., Jambor, J. L. & Weisener, C. G. in Treatise on Geochemistry Vol. 9 (eds Holland, H. D., Turekian, K. K. & Lollar B. S.) 149–204 (Elsevier, 2003).

  6. 6.

    Nordstrom, D. K. & Alpers, C. N. Negative pH, efflorescent mineralogy, and consequences for environmental restoration at the Iron Mountain Superfund site, California. Proc. Natl Acad. Sci. USA 96, 3455–3462 (1999).

    Google Scholar 

  7. 7.

    Nordstrom, D. K. & Ball, J. W. The geochemical behavior of aluminum in acidified surface waters. Science 232, 54–56 (1986).

    Google Scholar 

  8. 8.

    Hecht, H. & Kölling, M. Investigation of pyrite-weathering processes in the vadose zone using optical oxygen sensors. Environ. Geol. 42, 800–809 (2002).

    Google Scholar 

  9. 9.

    Markovic, S., Paytan, A. & Wortmann, U. G. Pleistocene sediment offloading and the global sulfur cycle. Biogeosciences 12, 3043–3060 (2015).

    Google Scholar 

  10. 10.

    Torres, M. A., Moosdorf, N., Hartmann, J., Adkins, J. F. & West, A. J. Glacial weathering, sulfide oxidation, and global carbon cycle feedbacks. Proc. Natl Acad. Sci. USA 114, 8716–8721 (2017).

    Google Scholar 

  11. 11.

    Burke, A. et al. Sulfur isotopes in rivers: insights into global weathering budgets, pyrite oxidation, and the modern sulfur cycle. Earth Planet. Sci. Lett. 496, 168–177 (2018).

    Google Scholar 

  12. 12.

    Torres, M. A., West, A. J. & Li, G. Sulphide oxidation and carbonate dissolution as a source of CO2 over geological timescales. Nature 507, 346–349 (2014).

    Google Scholar 

  13. 13.

    Broecker, W. S. Ocean chemistry during glacial time. Geochim. Cosmochim. Acta 46, 1689–1705 (1982).

    Google Scholar 

  14. 14.

    Milliman, J. D. Production and accumulation of calcium carbonate in the ocean: budget of a nonsteady state. Glob. Biogeochem. Cycles 7, 927–957 (1993).

    Google Scholar 

  15. 15.

    Turchyn, A. V. & Schrag, D. P. Oxygen isotope constraints on the sulfur cycle over the past 10 million years. Science 303, 2004–2007 (2004).

    Google Scholar 

  16. 16.

    Bereiter, B. et al. Revision of the EPICA Dome C CO2 record from 800 to 600 kyr before present. Geophys. Res. Lett. 42, 542–549 (2015).

    Google Scholar 

  17. 17.

    Lüthi, D. et al. High-resolution carbon dioxide concentration record 650,000–800,000 years before present. Nature 453, 379–382 (2008).

    Google Scholar 

  18. 18.

    Foster, G. L. & Rohling, E. J. Relationship between sea level and climate forcing by CO2 on geological timescales. Proc. Natl Acad. Sci. USA 110, 1209–1214 (2013).

    Google Scholar 

  19. 19.

    Berger, W. H., Yasuda, M. K., Bickert, T. & Wefer, G. Reconstruction of atmospheric CO2 from ice-core data and the deep-sea record of Ontong Java plateau: the Milankovitch chron. Geol. Rundsch. 85, 466–495 (1996).

    Google Scholar 

  20. 20.

    Galbraith, E. D. & Eggleston, S. A lower limit to atmospheric CO2 concentrations over the past 800,000 years. Nat. Geosci. 10, 295–298 (2017).

    Google Scholar 

  21. 21.

    Skinner, L. C., Fallon, S., Waelbroeck, C., Michel, E. & Barker, S. Ventilation of the deep Southern Ocean and deglacial CO2 rise. Science 328, 1147–1151 (2010).

    Google Scholar 

  22. 22.

    Martínez-Botí, M. A. et al. Boron isotope evidence for oceanic carbon dioxide leakage during the last deglaciation. Nature 518, 219–222 (2015).

    Google Scholar 

  23. 23.

    Jaccard, S. L., Galbraith, E. D., Martinez-Garcia, A. & Anderson, R. F. Covariation of deep Southern Ocean oxygenation and atmospheric CO2 through the last ice age. Nature 530, 207–210 (2016).

    Google Scholar 

  24. 24.

    Sikes, E. L., Samson, C. R., Guilderson, T. P. & Howard, W. R. Old radiocarbon ages in the southwest Pacific Ocean during the last glacial period and deglaciation. Nature 405, 555–559 (2000).

    Google Scholar 

  25. 25.

    Ridgwell, A. J., Watson, A. J., Maslin, M. A. & Kaplan, J. O. Implications of coral reef buildup for the controls on atmospheric CO2 since the Last Glacial Maximum. Paleoceanography 18, 1083 (2003).

    Google Scholar 

  26. 26.

    Berger, W. H. Increase of carbon dioxide in the atmosphere during deglaciation: the coral reef hypothesis. Naturwissenschaften 69, 87–88 (1982).

    Google Scholar 

  27. 27.

    Horan, K. et al. Mountain glaciation drives rapid oxidation of rock-bound organic carbon. Sci. Adv. 3, e1701107 (2017).

    Google Scholar 

  28. 28.

    Georg, R. B., West, A. J., Vance, D., Newman, K. & Halliday, A. N. Is the marine osmium isotope record a probe for CO2 release from sedimentary rocks? Earth Planet. Sci. Lett. 367, 28–38 (2013).

    Google Scholar 

  29. 29.

    Indermuhle, A. et al. Holocene carbon-cycle dynamics based on CO2 trapped in ice at Taylor Dome, Antarctica. Nature 398, 121–126 (1999).

    Google Scholar 

  30. 30.

    Hallmann, N. et al. Ice volume and climate changes from a 6,000 year sea-level record in French Polynesia. Nat. Commun. 9, 285 (2018).

    Google Scholar 

  31. 31.

    Stolper, D. A., Bender, M. L., Dreyfus, G. B., Yan, Y. & Higgins, J. A. A Pleistocene ice core record of atmospheric O2 concentrations. Science 353, 1427–1430 (2016).

    Google Scholar 

  32. 32.

    Hönisch, B. et al. The geological record of ocean acidification. Science 335, 1058–1063 (2012).

    Google Scholar 

  33. 33.

    Kelemen, P. B. & Manning, C. E. Reevaluating carbon fluxes in subduction zones, what goes down, mostly comes up. Proc. Natl Acad. Sci. USA 112, E3997–E4006 (2015).

    Google Scholar 

  34. 34.

    Sweeney, C. et al. Constraining global air–sea gas exchange for CO2 with recent bomb 14C measurements. Glob. Biogeochem. Cycles 21, GB2015 (2007).

    Google Scholar 

  35. 35.

    Zeebe, R. E. & Caldeira, K. Close mass balance of long-term carbon fluxes from ice-core CO2 and ocean chemistry records. Nat. Geosci. 1, 312–315 (2008).

    Google Scholar 

  36. 36.

    Brovkin, V., Ganopolski, A., Archer, D. & Munhoven, G. Glacial CO2 cycle as a succession of key physical and biogeochemical processes. Clim 8, 251–264 (2012).

    Google Scholar 

  37. 37.

    Shakun, J. D. et al. Global warming preceded by increasing carbon dioxide concentrations during the last deglaciation. Nature 484, 49–54 (2012).

    Google Scholar 

  38. 38.

    Ronge, T. A. et al. Radiocarbon constraints on the extent and evolution of the South Pacific glacial carbon pool. Nat. Commun. 7, 11487 (2016).

    Google Scholar 

  39. 39.

    Maslin, M. A. & Brierley, C. M. The role of orbital forcing in the Early Middle Pleistocene Transition. Quat. Int. 389, 47–55 (2015).

    Google Scholar 

  40. 40.

    Hays, J. D., Imbrie, J. & Shackleton, N. J. Variations in the Earth’s orbit: pacemaker of the ice ages. Science 194, 1121–1132 (1976).

    Google Scholar 

  41. 41.

    Eakins, B. W. & Sharman, G. F. Hypsographic curve of Earth’s surface from ETOPO1. NOAA National Centers for Environmental Information (2012).

  42. 42.

    Paillard, D., Labeyrie, L. & Yiou, P. Macintosh program performs time-series analysis. Eos 77, 379 (1996).

    Google Scholar 

  43. 43.

    Laskar, J. et al. A long-term numerical solution for the insolation quantities of the Earth. Astron. Astrophys. 428, 261–285 (2004).

    Google Scholar 

  44. 44.

    Koelling, M. et al. SEALEX—internal reef chronology and virtual drill logs from a spreadsheet-based reef growth model. Glob. Planet. Change 66, 149–159 (2009).

    Google Scholar 

  45. 45.

    Kölling, M. & Schüring, J. Pyrite weathering in coal mine tailings. In Water Down Under 94, Groundwater Papers, National Conference Papers 94/14 Vol. 2, Pt. B 545–550 (Institution of Engineers, 1994).

  46. 46.

    Bowles, M. W., Mogollón, J. M., Kasten, S., Zabel, M. & Hinrichs, K.-U. Global rates of marine sulfate reduction and implications for sub-sea-floor metabolic activities. Science 344, 889–891 (2014).

    Google Scholar 

  47. 47.

    Goldhaber, M. B. in Treatise on Geochemistry Vol. 7 (eds Holland, H. D., Turekian, K. K. & Mackenzie, F. T.) 257–288 (Pergamon, 2003).

  48. 48.

    Gatland, J. R., Santos, I. R., Maher, D. T., Duncan, T. M. & Erler, D. V. Carbon dioxide and methane emissions from an artificially drained coastal wetland during a flood: implications for wetland global warming potential. J. Geophys. Res. Biogeosci. 119, 1698–1716 (2014).

    Google Scholar 

  49. 49.

    Lowson, R. T. Aqueous oxidation of pyrite by molecular oxygen. Chem. Rev. 82, 461–497 (1982).

    Google Scholar 

  50. 50.

    Berner, R. A. Sedimentary pyrite formation: an update. Geochim. Cosmochim. Acta 48, 605–615 (1984).

    Google Scholar 

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This work was funded by the DFG under Germany’s Excellence Strategy, no. EXC-2077–390741603.

Author information




M.K. designed the model and drafted the manuscript with input from I.B., M.W.B., T.F., T.G., K.-U.H., M.S. and M.Z.

Corresponding author

Correspondence to Martin Kölling.

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The authors declare no competing interests.

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Peer review information Primary Handling Editor(s): James Super, Rebecca Neely.

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Supplementary information

Supplementary Information

Supplementary text and Figs. 1–10.

Reference run results

Supplementary dataset

PYREX Model worksheet

Supplementary dataset

PYREX model run

Supplementary video.

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Kölling, M., Bouimetarhan, I., Bowles, M.W. et al. Consistent CO2 release by pyrite oxidation on continental shelves prior to glacial terminations. Nat. Geosci. 12, 929–934 (2019).

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