Letter | Published:

Primordial clays on Mars formed beneath a steam or supercritical atmosphere

Nature volume 552, pages 8891 (07 December 2017) | Download Citation


On Mars, clay minerals are widespread in terrains that date back to the Noachian period (4.1 billion to 3.7 billion years ago)1,2,3,4,5. It is thought that the Martian basaltic crust reacted with liquid water during this time to form hydrated clay minerals3,6. Here we propose, however, that a substantial proportion of these clays was formed when Mars’ primary crust reacted with a dense steam or supercritical atmosphere of water and carbon dioxide that was outgassed during magma ocean cooling7,8,9. We present experimental evidence that shows rapid clay formation under conditions that would have been present at the base of such an atmosphere and also deeper in the porous crust. Furthermore, we explore the fate of a primordial clay-rich layer with the help of a parameterized crustal evolution model; we find that the primordial clay is locally disrupted by impacts and buried by impact-ejected material and by erupted volcanic material, but that it survives as a mostly coherent layer at depth, with limited surface exposures. These exposures are similar to those observed in remotely sensed orbital data from Mars1,2,3,4,5. Our results can explain the present distribution of many clays on Mars, and the anomalously low density of the Martian crust in comparison with expectations.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.


  1. 1.

    et al. Mars surface diversity as revealed by the OMEGA/Mars Express observations. Science 307, 1576–1581 (2005)

  2. 2.

    et al. Hydrated silicate minerals on Mars observed by the Mars Reconnaissance Orbiter CRISM instrument. Nature 454, 305–309 (2008)

  3. 3.

    et al. Subsurface water and clay mineral formation during the early history of Mars. Nature 479, 53–60 (2011)

  4. 4.

    , , , & Hydrous minerals on Mars as seen by the CRISM and OMEGA imaging spectrometers: updated global view. J. Geophys. Res. Planets 118, 831–858 (2013)

  5. 5.

    & Ancient and recent clay formation on Mars as revealed from a global survey of hydrous minerals in crater central peaks. J. Geophys. Res. Planets 120, 2293–2332 (2015)

  6. 6.

    , , , & Widespread surface weathering on early Mars: a case for a warmer and wetter climate. Icarus 248, 373–382 (2015)

  7. 7.

    Linked magma ocean solidification and atmospheric growth for Earth and Mars. Earth Planet. Sci. Lett. 271, 181–191 (2008)

  8. 8.

    Physical state of the very early Earth. Lithos 30, 223–235 (1993)

  9. 9.

    et al. Outgassing history and escape of the Martian atmosphere and water inventory. Space Sci. Rev. 174, 113–154 (2013)

  10. 10.

    & Hf–W–Th evidence for rapid growth of Mars and its status as a planetary embryo. Nature 473, 489–492 (2011)

  11. 11.

    , , , & The age of Dar al Gani 476 and the differentiation history of the martian meteorites inferred from their radiogenic isotopic systematics. Geochim. Cosmochim. Acta 67, 3519–3536 (2003)

  12. 12.

    & Early plate tectonics versus single-plate tectonics on Mars: evidence from magnetic field history and crust evolution. J. Geophys. Res. Planets 108, 5072 (2003)

  13. 13.

    et al. Constraints on the crystal-chemistry of Fe/Mg-rich smectitic clays on Mars and links to global alteration trends. Earth Planet. Sci. Lett. 427, 215–225 (2015)

  14. 14.

    et al. Oxidative alteration of ferrous smectites: a formation pathway for Martian nontronite? Lunar Planet. Sci. Conf. XLVII, abstract 2520 (2017)

  15. 15.

    et al. The crust of the Moon as seen by GRAIL. Science 339, 671–675 (2013)

  16. 16.

    Controls on primary porosity and permeability development in igneous rocks. Geol. Soc. Spec. Pub. 214, 93–107 (2003)

  17. 17.

    A model for the hydrologic and climatic behavior of water on Mars. J. Geophys. Res. Planets 98, 10973–11016 (1993)

  18. 18.

    , & Mega-impact formation of the Mars hemispheric dichotomy. Nature 453, 1216–1219 (2008)

  19. 19.

    et al. The early differentiation of Mars inferred from Hf–W chronometry. Earth Planet. Sci. Lett. 474, 345–354 (2017)

  20. 20.

    , , & A sawtooth-like timeline for the first billion years of lunar bombardment. Earth Planet. Sci. Lett. 355, 144–151 (2012)

  21. 21.

    & A post-accretionary lull in large impacts on early Mars. Nat. Geosci. 10, 344–348 (2017)

  22. 22.

    et al. X-ray diffraction results from Mars science laboratory: mineralogy of rocknest at Gale Crater. Science 341, 1238932 (2013)

  23. 23.

    et al. Geologic history of Martian regolith breccia Northwest Africa 7034: evidence for hydrothermal activity and lithologic diversity in the Martian crust. J. Geophys. Res. Planets 121, 2120–2149 (2016)

  24. 24.

    , & Evidence for a widespread basaltic breccia component in the martian low-albedo regions from the reflectance spectrum of Northwest Africa 7034. Icarus 252, 150–153 (2015)

  25. 25.

    , , & Compositional and structural constraints on the geologic history of eastern Tharsis Rise, Mars. Icarus 284, 43–58 (2017)

  26. 26.

    et al. An impact origin for hydrated silicates on Mars: a synthesis. J. Geophys. Res. Planets 118, 994–1012 (2013)

  27. 27.

    et al. Magmatic precipitation as a possible origin of Noachian clays on Mars. Nat. Geosci. 5, 739–743 (2012)

  28. 28.

    , , , & Comparison of “warm and wet” and “cold and icy” scenarios for early Mars in a 3-D climate model. J. Geophys. Res. Planets 120, 1201–1219 (2015)

  29. 29.

    in Volatiles in the Martian Crust (Elsevier, 2017)

  30. 30.

    et al. Petrological constraints on the density of the Martian crust. J. Geophys. Res. Planets 119, 1707–1727 (2014)

  31. 31.

    et al. Unique meteorite from early Amazonian Mars: water-rich basaltic breccia Northwest Africa 7034. Science 339, 780–785 (2013)

  32. 32.

    Strength of mineral absorption features in the transmitted component of near-infrared reflected light: first results from RELAB. J. Geophys. Res. 88, 9534–9544 (1983)

  33. 33.

    ., ., ., & The USGS digital spectral library 93–592 (US Geol. Surv. Open File Rep., 1993)

  34. 34.

    Martian cratering 8: isochron refinement and the chronology of Mars. Icarus 174, 294–320 (2005)

  35. 35.

    , , & Large impact crater histories of Mars: the effect of different model crater age techniques. Icarus 225, 173–184 (2013)

  36. 36.

    The scaling of complex craters. J. Geophys. Res. Solid Earth 90, C828–C842 (1985)

  37. 37.

    , , & North polar region craterforms on Mars: geometric characteristics from the Mars orbiter laser altimeter. Icarus 144, 329–352 (2000)

  38. 38.

    , & Differential melt scaling for oblique impacts on terrestrial planets. Icarus 218, 906–916 (2012)

  39. 39.

    & A new global database of Mars impact craters ≥1 km: 2. Global crater properties and regional variations of the simple-to-complex transition diameter. J. Geophys. Res. Planet. 117, E06001 (2012)

  40. 40.

    , & Crustal recycling, mantle dehydration, and the thermal evolution of Mars. Icarus 212, 541–558 (2011)

Download references


Thanks to M. Rutherford, T. Hiroi and J. Bosenberg for assistance with experiments and instrumental measurements. Discussions with R. Milliken were helpful in identifying clay minerals in the altered samples.

Author information


  1. Department of Earth, Environmental and Planetary Sciences, Brown University, Providence, Rhode Island 02912, USA

    • Kevin M. Cannon
    • , Stephen W. Parman
    •  & John F. Mustard
  2. Department of Physics, University of Central Florida, Orlando, Florida 32816, USA

    • Kevin M. Cannon


  1. Search for Kevin M. Cannon in:

  2. Search for Stephen W. Parman in:

  3. Search for John F. Mustard in:


K.M.C. and S.W.P. conceived the study; K.M.C. undertook the alteration experiments and interpreted the results along with J.F.M.; K.M.C. developed the crustal evolution model and wrote the paper; all authors read the paper and contributed comments.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to Kevin M. Cannon.

Reviewer Information Nature thanks F. McCubbin, L. Schaefer and the other anonymous reviewer(s) for their contribution to the peer review of this work.

Publisher's note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Extended data

About this article

Publication history






Further reading


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.