Letter | Published:

Geochemical evidence for magmatic water within Mars from pyroxenes in the Shergotty meteorite

Nature volume 409, pages 487490 (25 January 2001) | Download Citation

Subjects

Abstract

Observations of martian surface morphology have been used to argue that an ancient ocean once existed on Mars1. It has been thought that significant quantities of such water could have been supplied to the martian surface through volcanic outgassing, but this suggestion is contradicted by the low magmatic water content that is generally inferred from chemical analyses of igneous martian meteorites2. Here, however, we report the distributions of trace elements within pyroxenes of the Shergotty meteorite—a basalt body ejected 175 million years ago from Mars3—as well as hydrous and anhydrous crystallization experiments that, together, imply that water contents of pre-eruptive magma on Mars could have been up to 1.8%. We found that in the Shergotty meteorite, the inner cores of pyroxene minerals (which formed at depth in the martian crust) are enriched in soluble trace elements when compared to the outer rims (which crystallized on or near to the martian surface). This implies that water was present in pyroxenes at depth but was largely lost as pyroxenes were carried to the surface during magma ascent. We conclude that ascending magmas possibly delivered significant quantities of water to the martian surface in recent times, reconciling geologic and petrologic constraints on the outgassing history of Mars.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

References

  1. 1.

    et al. Possible ancient oceans on Mars: Evidence from Mars Orbiter laser altimeter data. Science 286, 2134– 2137 (1999).

  2. 2.

    & Chemistry and accretion history of Mars. Phil. Trans. R. Soc. Lond. A 349, 285–293 (1994).

  3. 3.

    What we have learned about Mars from SNC meteorites. Meteoritics 29, 757–779 ( 1994).

  4. 4.

    , , & Water in SNC meteorites: Evidence for a martian hydrosphere. Science 255, 1409–1411 (1992).

  5. 5.

    & Petrology and origin of the shergottite meteorites. Geochim. Cosmochim. Acta 43, 1475–1498 ( 1979).

  6. 6.

    & Outgassed water on Mars: Constraints from melt inclusions in SNC meteorites. Science 259, 1890–1892 ( 1993).

  7. 7.

    , , & Water on Mars: Clues from deuterium/hydrogen and water contents of hydrous phases in SNC meteorites. Science 265, 86 –90 (1994).

  8. 8.

    , , & The role of H2O in martian magmatic systems. Am. Mineral. 83, 942–946 (1998).

  9. 9.

    , , , & Oxy-substitution and dehydrogenation in mantle-derived amphibole megacrysts. Geochim. Cosmochim. Acta 63, 3635–3651 (1999).

  10. 10.

    , & Alteration of the oceanic crust: implications for geochemical cycles of lithium and boron. Geochim. Cosmochim. Acta 48, 557–569 (1984).

  11. 11.

    , & The role of aqueous fluids in the slab-to-mantle transfer of boron, beryllium, and lithium during subduction: Experiments and models. Geochim. Cosmochim. Acta 62, 33337 –3347 (1998).

  12. 12.

    & A negative Ce anomaly in a peridotite xenolith: Evidence for crustal recycling into the mantle or mantle metasomatism? Geochim. Cosmochim. Acta 53, 1035– 1040 (1989).

  13. 13.

    , & Re-evaluation of intercumulus liquid composition and oxidation state for the Shergotty meteorite. Geochim. Cosmochim. Acta 63, 1459–1470 (1999).

  14. 14.

    , , , & The Shergotty paradox: An experimental perspective on intercumulus melt compositions. Lunar Planet. Sci. [CD-ROM] 31 (2000).

  15. 15.

    & Crystallization of the Zagami shergottite: An experimental study. Earth Planet. Sci. Lett. 173, 397–411 (1999).

  16. 16.

    , & QUILF: A Pascal program to assess equilibria among Fe-Mg-Mn-Ti oxides, pyroxenes, olivine, and quartz. Comput. Geosci. 19, 1333–1350 ( 1993).

  17. 17.

    , & The solubility of water and effects of oxygen fugacity and water content on crystallization in mafic magmas. J. Petrol. 5, 21–39 (1964 ).

  18. 18.

    & Experimental investigations of the role of H2O in calc-alkaline differentiation and subduction zone magmatism. Contrib. Mineral. Petrol. 113, 143–166 (1993).

  19. 19.

    , & An empirical model for the solubility of H 2O in magmas to 3 kilobars. Am. Mineral. 83, 36–42 (1998).

  20. 20.

    , & Chassigny petrogenesis: Melt compositions, intensive parameters, and water contents of martian(?) magmas. Geochim. Cosmochim. Acta 55, 349–366 ( 1991).

  21. 21.

    & Genesis of the Mars Pathfinder “sulfur-free” rock from SNC parental liquids. Geochim. Cosmochim. Acta 64, 2535– 2547 (2000).

  22. 22.

    & Ascent and eruption of basaltic magma on the Earth and Moon. J. Geophys. Res. 86, 2971–3001 (1981).

  23. 23.

    , & in Mars (eds Kieffer, H. H., Jakosky, B. M., Snyder, C. W. & Matthews, M. S.) 424–452 (Univ. Arizona Press, Tucson, 1992).

  24. 24.

    , & Water, carbon dioxide, and hydrogen isotopes in glasses from the ca. 1340 A. D. eruption of the Mono Craters, California: Constraints on degassing phenomena and initial volatile content. J. Volcanol. Geotherm. Res. 35, 75–96 (1988).

  25. 25.

    , , & In situ compositions of Martian volcanics: Implications for the mantle. J. Geophys. Res. 102, 25605–25615 ( 1997).

  26. 26.

    , & A global view of martian surface compositions from MGS-TES. Science 287, 1626– 1630 (2000).

  27. 27.

    & Jr An oxygen isotope model for the composition of Mars. Icarus 126, 373– 394 (1997).

  28. 28.

    Isotopic relationships among the shergottites, the nakhlites and Chassigny. Proc. Lunar Planet. Sci. Conf. 19, 465– 474 (1989).

  29. 29.

    Complex magmatic processes on Mars: Inferences from the SNC meteorites. Proc. Lunar Planet. Sci. Conf. 21, 695– 709 (1991).

  30. 30.

    & Oxygen fugacity of the martian basalts from analysis of iron-titanium oxides: Implications for mantle-crust interaction on Mars. Met. Planet. Sci. 35, A70 (2000).

Download references

Acknowledgements

This work was partly supported by NASA.

Author information

Affiliations

  1. *Department of Geological Sciences, University of Tennessee, Knoxville, Tennessee 37996, USA

    • Harry Y. McSween Jr
    •  & Rachel C. F. Lentz
  2. †Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge , Massachusetts 02139, USA

    • Timothy L. Grove
    • , Jesse C. Dann
    •  & Astrid H. Holzheid
  3. ‡Chemical and Analytical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA

    • Lee R. Riciputi
  4. §Department of Geology, University of South Florida, Tampa, Florida 33620, USA

    • Jeffrey G. Ryan

Authors

  1. Search for Harry Y. McSween in:

  2. Search for Timothy L. Grove in:

  3. Search for Rachel C. F. Lentz in:

  4. Search for Jesse C. Dann in:

  5. Search for Astrid H. Holzheid in:

  6. Search for Lee R. Riciputi in:

  7. Search for Jeffrey G. Ryan in:

Corresponding author

Correspondence to Harry Y. McSween Jr.

Supplementary information

About this article

Publication history

Received

Accepted

Published

DOI

https://doi.org/10.1038/35054011

Further reading

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.