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Magnesium sulphate salts and the history of water on Mars

Nature volume 431, pages 663–665 (2004)Cite this article

Abstract

Recent reports of ∼30 wt% of sulphate within saline sediments on Mars1,2—probably occurring in hydrated form3—suggest a role for sulphates in accounting for equatorial H2O observed in a global survey by the Odyssey spacecraft4. Among salt hydrates likely to be present3, those of the MgSO4·nH2O series have many hydration states. Here we report the exposure of several of these phases to varied temperature, pressure and humidity to constrain their possible H2O contents under martian surface conditions. We found that crystalline structure and H2O content are dependent on temperature–pressure history, that an amorphous hydrated phase with slow dehydration kinetics forms at <1% relative humidity, and that equilibrium calculations may not reflect the true H2O-bearing potential of martian soils. Mg sulphate salts can retain sufficient H2O to explain a portion of the Odyssey observations5. Because phases in the MgSO4·nH2O system are sensitive to temperature and humidity, they can reveal much about the history of water on Mars. However, their ease of transformation implies that salt hydrates collected on Mars will not be returned to Earth unmodified, and that accurate in situ analysis is imperative.

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Figure 1: Dehydration experiment in an environmental cell.
Figure 2: Rehydration experiment in an environmental cell.
Figure 3: Results of controlled-humidity XRD experiments at 298 K plotted against stability fields for epsomite, hexahydrite and kieserite, modified from ref. 19.

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References

  1. MER Rover web site. 〈http://www.jpl.nasa.gov/mer2004/rover-images/mar-02-2004/images-3-2-04.html〉 (March 2004).

  2. Brueckner, J. Determination of chemical composition of soils and rocks at the MER landing sites Gusev crater and Meridiani Planum using the APXS. Eos 85(17, Jt. Assem. Suppl.), abstract V11A–05 (2004)

  3. Clark, B. C. Implications of abundant hygroscopic minerals in the martian regolith. Icarus 34, 645–665 (1978)

    Article  ADS  CAS  Google Scholar 

  4. Feldman, W. C. et al. The global distribution of near-surface hydrogen on Mars. J. Geophys. Res. 109, doi:10.1029/2003JE002160 (2004)

  5. Feldman, W. C. et al. Hydrated states of MgSO4 at equatorial latitudes on Mars. Geophys. Res. Lett. 31, doi:10.1029/2004GL020181 (2004)

  6. Clark, B. C. et al. Inorganic analyses of martian surface samples at the Viking landing sites. Science 194, 1283–1288 (1976)

    Article  ADS  CAS  Google Scholar 

  7. Toulmin, P. III et al. Geochemical and mineralogical interpretation of the Viking inorganic chemical results. J. Geophys. Res. 82, 4625–4634 (1977)

    Article  ADS  CAS  Google Scholar 

  8. Wänke, H., Brückner, J., Dreibus, G., Rieder, R. & Ryabchikov, I. Chemical composition of rocks and soils at the Pathfinder site. Space Sci. Rev. 96, 317–330 (2001)

    Article  ADS  Google Scholar 

  9. Foley, C. N., Economou, T. & Clayton, R. N. Final chemical results from the Mars Pathfinder alpha proton X-ray spectrometer. J. Geophys. Res. 108, doi:10.1029/2002JE002019 (2003)

  10. McSween, H. Y. et al. Basaltic rocks analyzed by the Spirit Rover in Gusev Crater. Science 305, 842–845 (2004)

    Article  ADS  CAS  Google Scholar 

  11. Christensen, P. R. Martian dust mantling and surface composition: Interpretation of thermophysical properties. J. Geophys. Res. 87, 9985–9998 (1982)

    Article  ADS  Google Scholar 

  12. Gendrin, A. & Mustard, J. F. Sulfate-cemented soils detected in TES data through the application of an automatic band detection algorithm. Lunar Planet. Sci. XXXV, abstract 1205 (2004)

  13. Clark, B. C. & Baird, A. K. Is the martian lithosphere sulphur rich? J. Geophys. Res. 84, 8395–8403 (1979)

    Article  ADS  CAS  Google Scholar 

  14. Banin, A., Han, F. X. & Cicelsky, A. Acidic volatiles and the Mars soil. J. Geophys. Res. 102, 13341–13356 (1997)

    Article  ADS  CAS  Google Scholar 

  15. Mellon, M. T. & Jakosky, B. M. The distribution and behavior of martian ground ice during past and present epochs. J. Geophys. Res. 100, 11781–11799 (1995)

    Article  ADS  Google Scholar 

  16. Bish, D. L., Carey, J. W., Vaniman, D. T. & Chipera, S. J. Stability of hydrous minerals on the martian surface. Icarus 164, 96–103 (2003)

    Article  ADS  CAS  Google Scholar 

  17. Bish, D. L., Vaniman, D. T., Fialips, C., Carey, J. W. & Feldman, W. C. Can hydrous minerals account for the observed mid-latitude water on Mars? Sixth Int. Conf. on Mars, abstract 3066 (2003)

    Google Scholar 

  18. Clark, B. C. & Van Hart, D. C. The salts of Mars. Icarus 45, 370–378 (1981)

    Article  ADS  CAS  Google Scholar 

  19. Chou, I.-M. & Seal, R. R. II Determination of epsomite-hexahydrite equilibria by the humidity-buffer technique at 0.1 MPa with implications for phase equilibria in the system MgSO4-H2O. Astrobiology 3, 619–630 (2003)

    Article  ADS  CAS  Google Scholar 

  20. Hawthorne, F. C., Krivovichev, S. V. & Burns, P. C. in Sulfate Minerals: Crystallography, Geochemistry, and Environmental Significance (eds Alpers, C. N., Jambor, J. L. & Nordstrom, D. K.) 1–112 (Min. Soc. Am., Washington DC, 2000)

    Google Scholar 

  21. Chipera, S. J., Carey, J. W. & Bish, D. L. Controlled-humidity XRD analyses: Application to the study of smectite expansion/contraction. Adv. X-ray Anal. 39, 713–722 (1997)

    CAS  Google Scholar 

  22. Savijarvi, H. Mars boundary layer modeling: Diurnal moisture cycle and soil properties at the Viking Lander 1 site. Icarus 117, 120–127 (1995)

    Article  ADS  Google Scholar 

  23. Gounelle, M. & Zolensky, M. E. A terrestrial origin for sulfate veins in CI1 chondrites. Meteorit. Planet. Sci. 36, 1321–1329 (2001)

    Article  ADS  CAS  Google Scholar 

  24. Taylor, L. A., Mao, H. K. & Bell, P. M. “Rust” in the Apollo 16 rocks. Proc. 4th Lunar Sci. Conf. 829–839 (1973)

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Acknowledgements

This research was supported by Los Alamos National Laboratory – Directed Research and Development Funding and by a NASA Mars Fundamental Research Program grant. Comments and suggestions by J. F. Bell and B. C. Clark helped to improve this Letter.

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Authors and Affiliations

  1. Los Alamos National Laboratory (LANL), MS D462, Los Alamos, New Mexico, 87545, USA

    David T. Vaniman, Steve J. Chipera, Claire I. Fialips & J. William Carey

  2. Indiana University, 1001 E 10th St, Bloomington, Indiana, 47405, USA

    David L. Bish

  3. Los Alamos National Laboratory (LANL), MS D466, Los Alamos, New Mexico, 87545, USA

    William C. Feldman

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Correspondence to David T. Vaniman.

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Vaniman, D., Bish, D., Chipera, S. et al. Magnesium sulphate salts and the history of water on Mars. Nature 431, 663–665 (2004). https://doi.org/10.1038/nature02973

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