Production of sulphate-rich vapour during the Chicxulub impact and implications for ocean acidification

Journal name:
Nature Geoscience
Volume:
7,
Pages:
279–282
Year published:
DOI:
doi:10.1038/ngeo2095
Received
Accepted
Published online

The mass extinction event at the Cretaceous/Palaeogene boundary 65.5 Myr ago has been widely attributed to the Chicxulub impact1, 2, but the mechanisms of extinction remain debated1, 3, 4, 5, 6. In the oceans, near-surface planktonic foraminifera suffered severe declines, in contrast to the relatively high survival rates of bottom-dwelling benthic foraminifera7. The vapour produced by an impact into Chicxulub’s target rocks, which include sulphate-rich anhydrite, could have led to global acid rain, which can explain the pattern of oceanic extinctions4, 5. However, it has been suggested that most of the sulphur in the target rocks would have been released as sulphur dioxide and would have stayed in the stratosphere for a long time6. Here we show, from impact experiments into anhydrite at velocities exceeding 10 km s−1, that sulphur trioxide dominates over sulphur dioxide in the resulting vapour cloud. Our experiments suggest that the Chicxulub impact released a huge quantity of sulphur trioxide into the atmosphere, where it would have rapidly combined with water vapour to form sulphuric acid aerosol particles. We also find, using a theoretical model of aerosol coagulation following the Chicxulub impact, that larger silicate particles ejected during the impact efficiently scavenge sulphuric acid aerosol particles and deliver the sulphuric acid to the surface within a few days. The rapid surface deposition of sulphuric acid would cause severe ocean acidification and account for preferential extinction of planktonic over benthic foraminifera.

At a glance

Figures

  1. Schematic diagram of the experimental set-up.
    Figure 1: Schematic diagram of the experimental set-up.

    A tantalum flyer and anhydrite target were placed in a large vacuum chamber. A laser-irradiated plastic ablator was attached to the front surface of the Ta flyer. The laser energy was absorbed by the ablator and the generated ablation plasma acted to accelerate the flyer. The chemical composition of the impact-induced vapour plume was measured directly using a quadrupole mass spectrometer (QMS). The vapour was introduced to the QMS using an inhalation tube. A hollow aluminium sphere was used to prevent the dispersal of the impact-induced gas.

  2. The SO3/SO2 ratios of impact-induced vapours as a function of impact velocities and peak shock pressures for impacts involving Murchison meteorite and anhydrite, obtained from the mass spectra of vapours using a QMS.
    Figure 2: The SO3/SO2 ratios of impact-induced vapours as a function of impact velocities and peak shock pressures for impacts involving Murchison meteorite and anhydrite, obtained from the mass spectra of vapours using a QMS.

    The data show that SO3 is the dominant sulphur oxide species in the impact vapours at impact velocities of a few tens of kilometres per second. The error bars are related to the sensitivity error of the QMS. Variance between the experiments is related to the adhesion of SOx gases to the wall of the vacuum system.

  3. Modelled temporal trends in the oceanic CO32- concentrations at a water depth of 60 m, following the impact.
    Figure 3: Modelled temporal trends in the oceanic CO32− concentrations at a water depth of 60 m, following the impact.

    The red curve shows CO32− concentrations calculated using the mass flux of sulphuric acid on the surface of the ocean. The green curve shows the CO32− concentrations in the case of dissolution equilibria processes between CO2 in the oceans and atmosphere. The dashed lines indicate the saturation levels of aragonite and calcite. The yellow shading indicates undersaturation of the ocean with respect to CaCO3.

References

  1. Alvarez, L. W., Alvarez, W., Asaro, F. & Michel, H. V. Extraterrestrial cause for the Cretaceous–Tertiary extinction. Science 208, 10851108 (1980).
  2. Schulte, P. et al. The Chicxulub asteroid impact and mass extinction at the Cretaceous–Paleogene boundary. Science 327, 12141218 (2010).
  3. Wolbach, W. S. et al. Global fire at the Cretaceous–Tertiary boundary. Nature 334, 665669 (1988).
  4. Pope, K. O., Baines, K. H., Ocampo, A. C. & Ivanov, B. A. Impact winter at the Cretaceous/Tertiary extinctions: Results of a Chicxulub asteroid impact model. Earth Plant. Sci. Lett. 128, 719725 (1994).
  5. Pierazzo, E., Hahmann, A. N. & Sloan, L. C. Chicxulub and climate: Radiative perturbations of impact-produced S-bearing gases. Astrobiology 3, 99118 (2003).
  6. D’Hondt, S. et al. Surface-water acidification and extinction at the Cretaceous–Tertiary boundary. Geology 22, 983986 (1994).
  7. Sigurdsson, H. et al. Geochemical constraints on source region of Cretaceous/Tertiary impact glasses. Nature 353, 839842 (1991).
  8. Maruoka, T. & Koeberl, C. Acid-neutralizing scenario after the Cretaceous–Tertiary impact event. Geology 31, 489492 (2003).
  9. Vajda, V. et al. Indication of global deforestation at the Cretaceous– Tertiary boundary by New Zealand Fern Spike. Science 294, 17001702 (2001).
  10. Pope, K. O., Baines, K. H., Ocampo, A. C. & Ivanov, B. A. Energy, volatile production and climate effects of the Chicxulub Cretaceous/Tertiary impact. J. Geophys. Res. 102, 2164521664 (1997).
  11. Ohno, S. et al. Sulfur chemistry in laser-simulated impact vapor clouds: Implications for the K/T impact event. Earth Planet. Sci. Lett. 218, 347361 (2004).
  12. Kadono, T. et al. Impact experiments with a new technique for acceleration of projectiles to velocities higher than Earth’s escape velocity of 11.2 km/s. J. Geophys. Res. 115, E04003 (2010).
  13. Ohno, S. et al. Direct measurements of impact devolatilization of calcite using a laser gun. Geophys. Res. Lett. 35, L13202 (2008).
  14. Kadono, T. et al. in Proc. Shock Compression of Condensed Matter—2011 (eds Elert, M. L., Buttler, W. T., Borg, J. P., Jordan, J. L. & Vogler, T. J.) Flyer acceleration by high-power laser and impact experiments at velocities higher than 10 km/s. 847850 (American Institute of Physics, 2012).
  15. Ohno, S. et al. in Proc. Shock Compression of Condensed Matter—2011 (eds Elert, M. L., Buttler, W. T., Borg, J. P., Jordan, J. L. & Vogler, T. J.) Direct measurement of chemical composition of SOx in impact vapor using a laser gun. 851854 (American Institute of Physics, 2012).
  16. Yang, W. & Ahrens, T. J. Shock vaporization of anhydrite and global effects of the K/T bolide. Earth Plant. Sci. Lett. 156, 125140 (1998).
  17. Trinquier, A., Birck, J-L. & Allégre, C. J. The nature of the K/T impactor. A 54Cr reappraisal. Earth Plant. Sci. Lett. 241, 780788 (2006).
  18. Anderson, W. W. & Ahrens, T. J. in Proc. Shock Compression of Condensed Matter—1997 (eds Schmidt, S. C., Dandekar, D. P. & Forbes, J. W.) Shock wave equations of state of chondritic meteorites. 115118 (American Institute of Physics, 1998).
  19. Ivanov, B. A. et al. Degassing of sedimentary rocks due to Chicxulub impact: Hydrocode and physical simulations. Geol. Soc. Am. Special Paper 307, 125139 (1996).
  20. Toon, O. B. et al. Environmental perturbations caused by the impacts of asteroids and comets. Rev. Geophys. 35, 4178 (1997).
  21. Pope, K. O. Impact dust not the cause of the Cretaceous–Tertiary mass extinction. Geology 30, 99102 (2002).
  22. Pierazzo, E., Kring, D. A. & Melosh, H. J. Hydrocode simulations of the Chicxulub impact event and the production of climatically active gases. J. Geophys. Res. 103, 2860628625 (1998).
  23. Smit, J. The global stratigraphy of the Cretaceous–Tertiary boundary impact ejecta. Annu. Rev. Earth Planet. Sci. 27, 75113 (1999).
  24. Seinfeld, J. H. & Pandis, S. N. Atmospheric Chemistry and Physics: From Air Pollution to Climate Change (Wiley, (1998).
  25. Alegret, L., Thomas, E. & Lohmann, K. C. End-Cretaceous marine mass extinction not caused by productivity collapse. Proc. Natl Acad. Sci. USA 109, 728732 (2012).
  26. Brett, R. The Cretaceous-Tertiary extinction: A lethal mechanism involving anhydrite target rocks. Geochim. Cosmochim. Acta. 56, 36033606 (1992).
  27. Lyons, J. R. & Ahrens, T. J. in High-Pressure Shock Compression of Solids V (eds Davison, L., Horie, Y. & Sekine, T.) Terrestrial acidification at the K/T boundary. 181197 (Springer, (2003).
  28. Misra, S. & Froelich, P. N. Lithium isotope history of Cenozoic seawater: Changes in silicate weathering and reverse weathering. Science 335, 818823 (2012).
  29. Oliver, L. et al. Silicate weathering rates decoupled from the 87Sr/86Sr ratio of the dissolved load during Himalayan erosion. Chem. Geol. 201, 119139 (2003).
  30. Preisinger, A. et al. Cretaceous–Tertiary profile, rhythmic deposition, and geomagnetic polarity reversals of marine sediments near Bjala, Bulgaria. Geol. Soc. Am. Special Paper 356, 213229 (2002).

Download references

Author information

Affiliations

  1. Planetary Exploration Research Center, Chiba Institute of Technology, Chiba 275-0016, Japan

    • Sohsuke Ohno,
    • Kosuke Kurosawa,
    • Takafumi Matsui &
    • Seiji Sugita
  2. University of Occupational and Environmental Health, Kitakyushu 807-8555, Japan

    • Toshihiko Kadono
  3. Department of Complexity Science and Engineering, University of Tokyo, Kashiwa 277-8561, Japan

    • Taiga Hamura &
    • Seiji Sugita
  4. Department of Earth and Space Science, Graduate School of Science, Osaka University, Osaka 560-0043, Japan

    • Tatsuhiro Sakaiya
  5. Institute of Laser Engineering, Osaka University, Osaka 565-0871, Japan

    • Keisuke Shigemori,
    • Yoichiro Hironaka,
    • Takayoshi Sano &
    • Takeshi Watari
  6. Institut national de la recherche scientifique—Énergie Matériaux Télécommunications, Varennes J3X 1S2, Canada

    • Kazuto Otani

Contributions

S.O., T.K., T.M. and S.S. conceived the study and wrote the paper. S.O., T.K., K.K., T.H., T. Sakaiya, K.S., Y.H., T. Sano, T.W., K.O. and S.S. carried out the experimental work using the GXII and analysed the results. S.O. and S.S. created the sweeping out model and carried out the calculations.

Competing financial interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to:

Author details

Supplementary information

PDF files

  1. Supplementary Information (489 KB)

    Supplementary Information

Additional data