Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Gradual and sustained carbon dioxide release during Aptian Oceanic Anoxic Event 1a

Abstract

During the Aptian Oceanic Anoxic Event 1a, about 120 million years ago, black shales were deposited in all the main ocean basins1. The event was also associated with elevated sea surface temperatures2,3 and a calcification crisis in calcareous nannoplankton4. These environmental changes have been attributed to variations in atmospheric CO2 concentrations2,3,5,6, but the evolution of the carbon cycle during this event is poorly constrained. Here we present records of atmospheric CO2 concentrations across Oceanic Anoxic Event 1a derived from bulk and compound-specific δ13C from marine rock outcrops in southern Spain and Tunisia. We find that CO2 concentrations doubled in two steps during the oceanic anoxic event and remained above background values for approximately 1.5–2 million years before declining. The rise of CO2 concentrations occurred over several tens to hundreds of thousand years, and thus was unlikely to have resulted in any prolonged surface ocean acidification, suggesting that CO2 emissions were not the primary cause of the nannoplankton calcification crisis. We find that the period of elevated CO2 concentrations coincides with a shift in the oceanic osmium-isotope inventory7 associated with emplacement of the Ontong Java Plateau flood basalts, and conclude that sustained volcanic outgassing was the primary source of carbon dioxide during Oceanic Anoxic Event 1a.

This is a preview of subscription content, access via your institution

Relevant articles

Open Access articles citing this article.

Access options

Buy article

Get time limited or full article access on ReadCube.

$32.00

All prices are NET prices.

Figure 1: Study area.
Figure 2: Carbon-isotope records from Cau across OAE 1a.
Figure 3: Estimates of atmospheric CO2 across OAE 1a.

References

  1. Jenkyns, H. C. Geochemistry of oceanic anoxic events. Geochem. Geophys. Geosyst. 11, Q03004 (2010).

    Article  Google Scholar 

  2. Mutterlose, J., Bottini, C., Schouten, S. & Sinninghe Damsté, J. S. High sea-surface temperatures during the early Aptian Oceanic Anoxic Event 1a in the boreal realm. Geology 42, 439–442 (2014).

    Article  Google Scholar 

  3. Ando, A., Kaiho, K., Kawahata, H. & Kakegawa, T. Timing and magnitude of early Aptian extreme warming: unraveling primary δ18O variation in indurated pelagic carbonates at Deep Sea Drilling Project Site 463, central Pacific Ocean. Palaeogeogr. Palaeoclimatol. Palaeoecol. 260, 463–476 (2008).

    Article  Google Scholar 

  4. Erba, E. Nannofossils and superplumes: the early Aptian ‘nannoconid crisis’. Paleoceanography 9, 483–501 (1994).

    Article  Google Scholar 

  5. Erba, E., Bottini, C., Weissert, H. J. & Keller, C. E. Calcareous nannoplankton response to surface-water acidification around Oceanic Anoxic Event 1a. Science 329, 428–432 (2010).

    Article  Google Scholar 

  6. Méhay, S. et al. A volcanic CO2 pulse triggered the Cretaceous Oceanic Anoxic Event 1a and a biocalcification crisis. Geology 37, 819–822 (2009).

    Article  Google Scholar 

  7. Bottini, C., Cohen, A. S., Erba, E., Jenkyns, H. C. & Coe, A. L. Osmium-isotope evidence for volcanism, weathering, and ocean mixing during the early Aptian OAE 1a. Geology 40, 583–586 (2012).

    Article  Google Scholar 

  8. Kump, L. R., Bralower, T. J. & Ridgwell, A. Ocean acidification in deep time. Oceanography 22, 94–107 (2009).

    Article  Google Scholar 

  9. Gibbs, S. J., Robinson, S. A., Bown, P. R., Jones, T. D. & Henderiks, J. Comment on ‘Calcareous nannoplankton response to surface-water acidification around Oceanic Anoxic Event 1a’. Science 332, 175 (2011).

    Article  Google Scholar 

  10. Heimhofer, U., Hochuli, P. A., Herrle, J. O., Andersen, N. & Weissert, H. Absence of major vegetation and palaeoatmospheric p CO 2 changes associated with Oceanic Anoxic Event 1a (Early Aptian, SE France). Earth Planet. Sci. Lett. 223, 303–318 (2004).

    Article  Google Scholar 

  11. van Breugel, Y. et al. Synchronous negative carbon isotope shifts in marine and terrestrial biomarkers at the onset of the early Aptian oceanic anoxic event 1a: evidence for the release of 13C-depleted carbon into the atmosphere. Paleoceanography 22, PA1210 (2007).

    Article  Google Scholar 

  12. Beerling, D. J., Lomas, M. R. & Gröcke, D. R. On the nature of methane gas-hydrate dissociation during the Toarcian and Aptian Oceanic anoxic events. Am. J. Sci. 302, 28–49 (2002).

    Article  Google Scholar 

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

    Article  Google Scholar 

  14. Li, Y.-X. et al. Toward an orbital chronology for the early Aptian Oceanic Anoxic Event (OAE1a, 120 Ma). Earth Planet. Sci. Lett. 271, 88–100 (2008).

    Article  Google Scholar 

  15. Malinverno, A., Erba, E. & Herbert, T. D. Orbital tuning as an inverse problem: chronology of the early Aptian Oceanic Anoxic Event 1a (Selli Level) in the Cismon APTICORE. Paleoceanography 25, PA2203 (2010).

    Article  Google Scholar 

  16. Kuhnt, W., Holbourn, A. & Moullade, M. Transient global cooling at the onset of early Aptian Oceanic Anoxic Event (OAE) 1a. Geology 39, 323–326 (2011).

    Article  Google Scholar 

  17. Lorenzen, J. et al. A new sediment core from the Bedoulian (Lower Aptian) stratotype at Roquefort-La Bédoule, SE France. Cretac. Res. 39, 6–16 (2013).

    Article  Google Scholar 

  18. de Gea, G. A., Castro, J. M., Aguado, R., Ruiz-Ortiz, P. A. & Company, M. Lower Aptian carbon isotope stratigraphy from a distal carbonate shelf setting: the Cau section, Prebetic zone, SE Spain. Palaeogeogr. Palaeoclimatol. Palaeoecol. 200, 207–219 (2003).

    Article  Google Scholar 

  19. Aguado, R., Castro, J. M., Company, M. & Alfonso De Gea, G. Aptian bio-events—an integrated biostratigraphic analysis of the Almadich Formation, Inner Prebetic Domain, SE Spain. Cretac. Res. 20, 663–683 (1999).

    Article  Google Scholar 

  20. Quijano, M. L. et al. Organic geochemistry, stable isotopes, and facies analysis of the Early Aptian OAE—New records from Spain (Western Tethys). Palaeogeogr. Palaeoclimatol. Palaeoecol. 365–366, 276–293 (2012).

    Article  Google Scholar 

  21. Kump, L. R. & Arthur, M. A. Interpreting carbon-isotope excursions: carbonates and organic matter. Chem. Geol. 161, 181–198 (1999).

    Article  Google Scholar 

  22. Jarvis, I., Lignum, J. S., Gröcke, D. R., Jenkyns, H. C. & Pearce, M. A. Black shale deposition, atmospheric CO2 drawdown, and cooling during the Cenomanian–Turonian Oceanic Anoxic Event. Paleoceanography 26, PA3201 (2011).

    Article  Google Scholar 

  23. Menegatti, A. P. et al. High-resolution δ13C stratigraphy through the Early Aptian ‘Livello Selli’ of the Alpine Tethys. Paleoceanography 13, 530–545 (1998).

    Article  Google Scholar 

  24. Sinninghe Damsté, J. S., Kuypers, M. M. M., Pancost, R. D. & Schouten, S. The carbon isotopic response of algae, (cyano)bacteria, archaea and higher plants to the late Cenomanian perturbation of the global carbon cycle: insights from biomarkers in black shales from the Cape Verde Basin (DSDP Site 367). Org. Geochem. 39, 1703–1718 (2008).

    Article  Google Scholar 

  25. Royer, D. L., Pagani, M. & Beerling, D. J. Geobiological constraints on Earth system sensitivity to CO2 during the Cretaceous and Cenozoic. Geobiology 10, 298–310 (2012).

    Article  Google Scholar 

  26. Heldt, M., Bachmann, M. & Lehmann, J. Microfacies, biostratigraphy, and geochemistry of the hemipelagic Barremian–Aptian in north-central Tunisia: influence of the OAE 1a on the southern Tethys margin. Palaeogeogr. Palaeoclimatol. Palaeoecol. 261, 246–260 (2008).

    Article  Google Scholar 

  27. Tejada, M. L. G. et al. Ontong Java Plateau eruption as a trigger for the early Aptian oceanic anoxic event. Geology 37, 855–858 (2009).

    Article  Google Scholar 

  28. Ridgwell, A. & Schmidt, D. N. Past constraints on the vulnerability of marine calcifiers to massive carbon dioxide release. Nature Geosci. 3, 196–200 (2010).

    Article  Google Scholar 

  29. Uchikawa, J. & Zeebe, R. E. Examining possible effects of seawater pH decline on foraminiferal stable isotopes during the Paleocene–Eocene Thermal Maximum. Paleoceanography 25, PA2216 (2010).

    Article  Google Scholar 

  30. Popp, B. N., Takigiku, R., Hayes, J. M., Louda, J. W. & Baker, E. W. The post-Paleozoic chronology and mechanism of 13C depletion in primary marine organic matter. Am. J. Sci. 289, 436–454 (1989).

    Article  Google Scholar 

  31. Popp, B. N. et al. Effect of Phytoplankton cell geometry on carbon isotopic fractionation. Geochim. Cosmochim. Acta 62, 69–77 (1998).

    Article  Google Scholar 

  32. Laws, E. A., Popp, B. N., Cassar, N. & Tanimoto, J. 13C discrimination patterns in oceanic phytoplankton: likely influence of CO2 concentrating mechanisms, and implications for palaeoreconstructions. Funct. Plant Biol. 29, 323–333 (2002).

    Article  Google Scholar 

  33. Bidigare, R. R. et al. Consistent fractionation of 13C in nature and in the laboratory: growth-rate effects in some haptophyte algae. Glob. Biogeochem. Cycles 11, 279–292 (1997).

    Article  Google Scholar 

  34. Weiss, R. F. Carbon dioxide in water and seawater: the solubility of a non-ideal gas. Mar. Chem. 2, 203–215 (1974).

    Article  Google Scholar 

  35. Pagani, M., Zachos, J. C., Freeman, K. H., Tipple, B. & Bohaty, S. Marked decline in atmospheric carbon dioxide concentrations during the Paleogene. Science 309, 600–603 (2005).

    Article  Google Scholar 

  36. Schoon, P. L., Sluijs, A., Sinninghe Damsté, J. S. & Schouten, S. Stable carbon isotope patterns of marine biomarker lipids in the Arctic Ocean during Eocene Thermal Maximum 2. Paleoceanography 26, PA3215 (2011).

    Article  Google Scholar 

  37. Seki, O. et al. Alkenone and boron-based Pliocene p CO 2 records. Earth Planet. Sci. Lett. 292, 201–211 (2010).

    Article  Google Scholar 

  38. Badger, M. P. S. et al. CO2 drawdown following the middle Miocene expansion of the Antarctic Ice Sheet. Paleoceanography 28, 42–53 (2013).

    Article  Google Scholar 

  39. Raymo, M. E., Grant, B., Horowitz, M. & Rau, G. H. Mid-Pliocene warmth: stronger greenhouse and stronger conveyor. Mar. Micropaleontol. 27, 313–326 (1996).

    Article  Google Scholar 

  40. Freeman, K. H. & Hayes, J. M. Fractionation of carbon isotopes by phytoplankton and estimates of ancient CO2 levels. Glob. Biogeochem. Cycles 6, 185–198 (1992).

    Article  Google Scholar 

  41. Bice, K. L. et al. A multiple proxy and model study of Cretaceous upper ocean temperatures and atmospheric CO2 concentrations. Paleoceanography 21, PA2002 (2006).

    Article  Google Scholar 

  42. Schouten, S. et al. Biosynthetic effects on the stable carbon isotopic compositions of algal lipids: implications for deciphering the carbon isotopic biomarker record. Geochim. Cosmochim. Acta 62, 1397–1406 (1998).

    Article  Google Scholar 

  43. van Bentum, E. C., Reichart, G. J., Forster, A. & Sinninghe Damsté, J. S. Latitudinal differences in the amplitude of the OAE-2 carbon isotopic excursion: p CO 2 and paleo productivity. Biogeosciences 9, 717–731 (2012).

    Article  Google Scholar 

  44. Schouten, S., van Kaam-Peters, H. M. E., Rijpstra, W. I. C., Schoell, M. & Sinninghe Damsté, J. S. Effects of an oceanic anoxic event on the stable carbon isotopic composition of early Toarcian carbon. Am. J. Sci. 300, 1–22 (2000).

    Article  Google Scholar 

  45. Romanek, C. S., Grossman, E. L. & Morse, J. W. Carbon isotopic fractionation in synthetic aragonite and calcite: effects of temperature and precipitation rate. Geochim. Cosmochim. Acta 56, 419–430 (1992).

    Article  Google Scholar 

  46. Mook, W. G., Bommerson, J. C. & Staverman, W. H. Carbon isotope fractionation between dissolved bicarbonate and gaseous carbon dioxide. Earth Planet. Sci. Lett. 22, 169–176 (1974).

    Article  Google Scholar 

  47. Halverson, G. P., Hoffman, P. F., Schrag, D. P., Maloof, A. C. & Rice, A. H. N. Toward a Neoproterozoic composite carbon-isotope record. Geol. Soc. Am. Bull. 117, 1181–1207 (2005).

    Article  Google Scholar 

  48. Jenkyns, H. C. in Proceedings of the Ocean Drilling Program, Scientific Results Vol. 143 (eds Winterer, E. L., Sager, W. W., Firth, J. V. & Sinton, J. M.) 99–104 (Ocean Drilling Program, 1995).

    Google Scholar 

  49. Stoll, H. M. Limited range of interspecific vital effects in coccolith stable isotopic records during the Paleocene–Eocene thermal maximum. Paleoceanography 20, PA1007 (2005).

    Article  Google Scholar 

  50. Dumitrescu, M. & Brassell, S. C. Compositional and isotopic characteristics of organic matter for the early Aptian Oceanic Anoxic Event at Shatsky Rise, ODP Leg 198. Palaeogeogr. Palaeoclimatol. Palaeoecol. 235, 168–191 (2006).

    Article  Google Scholar 

  51. Grantham, P. J. & Wakefield, L. L. Variations in the sterane carbon number distributions of marine source rock derived crude oils through geological time. Org. Geochem. 12, 61–73 (1988).

    Article  Google Scholar 

  52. Schwark, L. & Empt, P. Sterane biomarkers as indicators of palaeozoic algal evolution and extinction events. Palaeogeogr. Palaeoclimatol. Palaeoecol. 240, 225–236 (2006).

    Article  Google Scholar 

  53. Volkman, J. Sterols in microorganisms. Appl. Microbiol. Biotechnol. 60, 495–506 (2003).

    Article  Google Scholar 

  54. Brassell, S. C. & Dumitrescu, M. Recognition of alkenones in a lower Aptian porcellanite from the west-central Pacific. Org. Geochem. 35, 181–188 (2004).

    Article  Google Scholar 

  55. Dumitrescu, M. & Brassell, S. C. Biogeochemical assessment of sources of organic matter and paleoproductivity during the early Aptian Oceanic Anoxic Event at Shatsky Rise, ODP Leg 198. Org. Geochem. 36, 1002–1022 (2005).

    Article  Google Scholar 

  56. Bottini, C. et al. Climate variability and ocean fertility during the Aptian Stage. Clim. Past 11, 383–402 (2015).

    Article  Google Scholar 

  57. Andersen, N., Müller, P. J., Kirst, G. & Schneider, R. R. in Use of Proxies in Paleoceanography (eds Fischer, G. & Wefer, G.) Ch. 19, 469–488 (Springer, 1999).

    Book  Google Scholar 

  58. Schulte, S., Benthien, A., Andersen, N., Müller, P. J. & Schneider, R. in The South Atlantic in the Late Quaternary: Reconstruction of Material Budget and Current Systems (eds Wefer, G., Mulitza, S. & Ratmeyer, V.) 195–211 (Springer, 2003).

    Book  Google Scholar 

  59. Pagani, M. The alkenone-CO2 Proxy and ancient atmospheric carbon dioxide. Phil. Trans. R. Soc. Lond. A 360, 609–632 (2002).

    Article  Google Scholar 

  60. Kuypers, M. M. M., van Breugel, Y., Schouten, S., Erba, E. & Sinninghe Damsté, J. S. N2-fixing cyanobacteria supplied nutrient N for Cretaceous oceanic anoxic events. Geology 32, 853–856 (2004).

    Article  Google Scholar 

  61. Pancost, R. D. et al. Reconstructing Late Ordovician carbon cycle variations. Geochim. Cosmochim. Acta 105, 433–454 (2013).

    Article  Google Scholar 

  62. Schouten, S., Hopmans, E. C., Schefuss, E. & Sinninghe Damsté, J. S. Distributional variations in marine crenarchaeotal membrane lipids: a new tool for reconstructing ancient sea water temperatures? Earth Planet. Sci. Lett. 204, 265–274 (2002).

    Article  Google Scholar 

  63. Schouten, S. et al. Extremely high sea-surface temperatures at low latitudes during the middle Cretaceous as revealed by archaeal membrane lipids. Geology 31, 1069–1072 (2003).

    Article  Google Scholar 

  64. Schouten, S., Hopmans, E. C. & Sinninghe Damsté, J. S. The effect of maturity and depositional redox conditions on archaeal tetraether lipid palaeothermometry. Org. Geochem. 35, 567–571 (2004).

    Article  Google Scholar 

  65. Schouten, S., Hopmans, E. C. & Sinninghe Damsté, J. S. The organic geochemistry of glycerol dialkyl glycerol tetraether lipids: a review. Org. Geochem. 54, 19–61 (2013).

    Article  Google Scholar 

  66. Kim, J.-H. et al. New indices and calibrations derived from the distribution of crenarchaeal isoprenoid tetraether lipids: implications for past sea surface temperature reconstructions. Geochim. Cosmochim. Acta 74, 4639–4654 (2010).

    Article  Google Scholar 

  67. Littler, K., Robinson, S. A., Bown, P. R., Nederbragt, A. J. & Pancost, R. D. High sea-surface temperatures during the Early Cretaceous Epoch. Nature Geosci. 4, 169–172 (2011).

    Article  Google Scholar 

  68. Jenkyns, H. C., Forster, A., Schouten, S. & Sinninghe Damsté, J. S. High temperatures in the Late Cretaceous Arctic Ocean. Nature 432, 888–892 (2004).

    Article  Google Scholar 

  69. Jenkyns, H. C., Schouten-Huibers, L., Schouten, S. & Sinninghe Damsté, J. S. Warm Middle Jurassic–Early Cretaceous high-latitude sea-surface temperatures from the Southern Ocean. Clim. Past 8, 215–226 (2012).

    Article  Google Scholar 

  70. Tarduno, J. A. et al. Evidence for extreme climatic warmth from Late Cretaceous Arctic vertebrates. Science 282, 2241–2243 (1998).

    Article  Google Scholar 

  71. Dumitrescu, M., Brassell, S. C., Schouten, S., Hopmans, E. C. & Sinninghe Damsté, J. S. Instability in tropical Pacific sea-surface temperatures during the early Aptian. Geology 34, 833–836 (2006).

    Article  Google Scholar 

  72. Hopmans, E. C. et al. A novel proxy for terrestrial organic matter in sediments based on branched and isoprenoid tetraether lipids. Earth Planet. Sci. Lett. 224, 107–116 (2004).

    Article  Google Scholar 

  73. Pearson, P. N. et al. Stable warm tropical climate through the Eocene Epoch. Geology 35, 211–214 (2007).

    Article  Google Scholar 

  74. Hu, X., Zhao, K., Yilmaz, I. O. & Li, Y. Stratigraphic transition and palaeoenvironmental changes from the Aptian Oceanic Anoxic Event 1a (OAE1a) to the Oceanic Red Bed 1 (ORB1) in the Yenicesihlar section, central Turkey. Cretac. Res. 38, 40–51 (2012).

    Article  Google Scholar 

  75. Huck, S., Heimhofer, U., Rameil, N., Bodin, S. & Immenhauser, A. Strontium and carbon-isotope chronostratigraphy of Barremian–Aptian shoal-water carbonates: northern Tethyan platform drowning predates OAE 1a. Earth Planet. Sci. Lett. 304, 547–558 (2011).

    Article  Google Scholar 

Download references

Acknowledgements

B.D.A.N. received funding through a Rubicon fellowship, awarded by the Netherlands Organisation for Scientific Research (NWO). Additional funding came from the advanced ERC grant ‘The greenhouse earth system’ (T-GRES). J.M.C. and M.L.Q. were funded by University of Jaén fellowships. D.N.S. was funded by a Royal Society URF. R.D.P. and D.N.S. acknowledge the Royal Society Wolfson Research Merit Award. We wish to thank the University of Jaén (CICT) for the use of analytical facilities and NERC for partial funding of the mass spectrometry facilities at the University of Bristol (contract no. R8/H10/63; www.lsmsf.co.uk). M. Heldt is thanked for providing the samples from Djebel Serdj. This work is a contribution of the research projects CGL2009-10329 and CGL2014-55274-P (Spanish Ministry of Science and Technology), ‘Episodios de Cambio Climático Global’ (Instituto de Estudios Giennenses) and RNM-200 (Junta de Andalucía).

Author information

Authors and Affiliations

Authors

Contributions

B.D.A.N., D.N.S. and R.D.P. designed the study. J.M.C. and G.A.D.G. generated the stratigraphy, gathered the samples in the field and prepared the samples for bulk stable isotope analyses. M.L.Q. and J.M.C. conducted the biomarker extraction and characterization of samples from Cau. B.D.A.N. performed the biomarker extraction of samples from Djebel Serdj, measured all compound-specific isotope data for Cau and Djebel Serdj, and wrote the manuscript with contributions from all authors.

Corresponding author

Correspondence to B. D. A. Naafs.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Information

Supplementary Information (PDF 1500 kb)

Supplementary Information

Supplementary Information (XLSX 75 kb)

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Naafs, B., Castro, J., De Gea, G. et al. Gradual and sustained carbon dioxide release during Aptian Oceanic Anoxic Event 1a. Nature Geosci 9, 135–139 (2016). https://doi.org/10.1038/ngeo2627

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/ngeo2627

Further reading

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing