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.

  • Letter
  • Published:

Water and its influence on the lithosphere–asthenosphere boundary

An Addendum to this article was published on 27 April 2011

Abstract

The Earth has distinctive convective behaviour, described by the plate tectonics model, in which lateral motion of the oceanic lithosphere of basaltic crust and peridotitic uppermost mantle is decoupled from the underlying mechanically weaker upper mantle (asthenosphere). The reason for differentiation at the lithosphere–asthenosphere boundary is currently being debated with relevant observations from geophysics (including seismology) and geochemistry (including experimental petrology). Water is thought to have an important effect on mantle rheology, either by weakening the crystal structure of olivine and pyroxenes by dilute solid solution1, or by causing low-temperature partial melting2. Here we present a novel experimental approach to clarify the role of water in the uppermost mantle at pressures up to 6 GPa, equivalent to a depth of 190 km. We found that for lherzolite in which a water-rich vapour is present, the temperature at which a silicate melt first appears (the vapour-saturated solidus) increases from a minimum of 970 °C at 1.5 GPa to 1,350 °C at 6 GPa. We have measured the water content in lherzolite to be approximately 180 parts per million, retained in nominally anhydrous minerals at 2.5 and 4 GPa at temperatures above and below the vapour-saturated solidus. The hydrous mineral pargasite is the main water-storage site in the uppermost mantle, and the instability of pargasite at pressures greater than 3 GPa (equivalent to more than about 90 km depth) causes a sharp drop in both the water-storage capacity and the solidus temperature of fertile upper-mantle lherzolite. The presence of interstitial melt in mantle with more than 180 parts per million of water at pressures greater than 3 GPa alters mantle rheology and defines the lithosphere–asthenosphere boundary. Modern asthenospheric mantle acting as the source for mid-oceanic ridge basalts has a water content of 50–200 parts per million (refs 3–5). We show that this matches the water content of residual nominally anhydrous minerals after incipient melting of lherzolite at the vapour-saturated solidus at high pressure.

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

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Figure 1: The vapour-saturated solidus and the water-storage capacity of HZ1 lherzolite.
Figure 2: Phase stability fields with different water contents in HZ1 and HZ2 lherzolite compositions at 2.5 GPa.
Figure 3: Examples of FTIR spectra from lherzolite layer or from monomineralic olivine or pyroxene layers.

Similar content being viewed by others

References

  1. Hirth, G. & Kohlstedt, D. L. Water in the oceanic upper mantle: implications for rheology, melt extraction and the evolution of the lithosphere. Earth Planet. Sci. Lett. 144, 93–108 (1996)

    Article  ADS  CAS  Google Scholar 

  2. Green, D. H. & Falloon, T. J. in The Earth's Mantle (ed. Jackson, I.) 311–378 (Cambridge Univ. Press, 1998)

    Google Scholar 

  3. Michael, P. J. Regionally distinctive sources of depleted MORB: evidence from trace elements and H2O. Earth Planet. Sci. Lett. 170, 215–239 (1995)

    Google Scholar 

  4. Danyushevsky, L. V., Eggins, S. M., Falloon, T. J. & Christie, D. M. H2O abundance in depleted to moderately enriched mid-ocean ridge magmas; Part I: incompatible behaviour, implications for mantle storage, and origin of regional variations. J. Petrol. 41, 1329–1364 (2000)

    Article  ADS  CAS  Google Scholar 

  5. Sobolev, A. V. & Chaussidon, M. H2O concentrations in primary melts from supra-subduction zones and mid-ocean ridges: implications for water storage and recycling in the mantle. Earth Planet. Sci. Lett. 137, 45–55 (1996)

    Article  ADS  CAS  Google Scholar 

  6. Wyllie, P. J. Mantle fluid compositions buffered in peridotite–CO2–H2O by carbonates, amphibole, and phlogopite. J. Geol. 86, 687–713 (1978)

    Article  ADS  CAS  Google Scholar 

  7. Green, D. H. Compositions of basaltic magmas as indicators of conditions of origin: application to oceanic volcanism. Phil. Trans. R. Soc. Lond. A 268, 707–725 (1971)

    Article  ADS  CAS  Google Scholar 

  8. Green, D. H. Experimental melting studies on a model upper mantle composition at high pressures under water-saturated and water-undersaturated conditions. Earth Planet. Sci. Lett. 19, 37–53 (1973)

    Article  ADS  CAS  Google Scholar 

  9. Hirschmann, M. M. Water, melting, and the deep Earth H2O cycle. Annu. Rev. Earth Planet. Sci. 34, 629–653 (2006)

    Article  ADS  CAS  Google Scholar 

  10. Asimow, P. D., Dixon, J. E. & Langmuir, C. H. A hydrous melting and fractionation model for mid-ocean ridge basalts: application to the Mid-Atlantic Ridge near the Azores. Geochem. Geophys. Geosyst. 5, 1–24 (2004)

    Article  Google Scholar 

  11. Tenner, T. J., Hirschmann, M. M., Withers, A. C. & Hervig, R. L. Hydrogen partitioning between nominally anhydrous upper mantle minerals and melt between 3 and 5 GPa and applications to hydrous peridotite partial melting. Chem. Geol. 262, 42–56 (2009)

    Article  ADS  CAS  Google Scholar 

  12. McKenzie, D. & Bickle, M. J. The volume and composition of melt generated by extension of the lithosphere. J. Petrol. 29, 625–679 (1988)

    Article  ADS  CAS  Google Scholar 

  13. Artemieva, I. M. The continental lithosphere: reconciling thermal, seismic and petrologic data. Lithos 109, 23–44 (2009)

    Article  ADS  CAS  Google Scholar 

  14. Thybo, H. The heterogeneous upper mantle low velocity zone. Tectonophysics 416, 53–79 (2006)

    Article  ADS  Google Scholar 

  15. Grove, T. L., Chatterjee, N., Parman, S. W. & Medard, E. The influence of H2O on mantle wedge melting. Earth Planet. Sci. Lett. 249, 74–89 (2006)

    Article  ADS  CAS  Google Scholar 

  16. Milhollen, G., Irving, A. J. & Wyllie, P. J. Melting interval of peridotite with 5.7 per cent water to 30 kilobars. J. Geol. 82, 575–587 (1974)

    Article  ADS  Google Scholar 

  17. Niida, K. & Green, D. H. Stability and chemical composition of pargasitic amphibole in MORB pyrolite under upper mantle conditions. Contrib. Mineral. Petrol. 135, 18–40 (1999)

    Article  ADS  CAS  Google Scholar 

  18. Bowen, N. L. & Tuttle, O. F. The system MgO–SiO2–H2O. Bull. Geol. Soc. Am. 60, 439–460 (1949)

    Article  CAS  Google Scholar 

  19. Asahara, Y. & Ohtani, E. Melting relations of the hydrous primitive mantle in the CMAS–H2O system at high pressures and temperatures, and implications for the generation of komatiites. Phys. Earth Planet. Inter. 125, 31–44 (2001)

    Article  ADS  CAS  Google Scholar 

  20. Green, D. H. Conditions of melting of basanite magma from garnet peridotite. Earth Planet. Sci. Lett. 17, 456–465 (1973)

    Article  ADS  CAS  Google Scholar 

  21. Brey, G. & Green, D. H. Systematic study of liquidus phase relations in olivine melilitite + H2O + CO2 at high pressures and petrogenesis of an olivine melilitite magma. Contrib. Mineral. Petrol. 61, 141–162 (1977)

    Article  ADS  CAS  Google Scholar 

  22. Green, D., Nicholls, I., Viljoen, M. & Viljoen, R. Experimental demonstration of the existence of periditic liquids in earliest Archean magmatism. Geology 3, 11–14 (1975)

    Article  ADS  CAS  Google Scholar 

  23. Mibe, K. et al. Second critical endpoint in the peridotite–H2O system. J. Geophys. Res. 112 B03201 10.1029/2005JB004125 (2007)

    Article  ADS  Google Scholar 

  24. Kessel, R., Ulmer, P., Pettke, T., Schmidt, M. W. & Thompson, A. B. The water–basalt system at 4 to 6 GPa: phase relations and second critical endpoint in a K-free eclogite at 700 to 1400 °C. Earth Planet. Sci. Lett. 237, 873–892 (2005)

    Article  ADS  CAS  Google Scholar 

  25. Kovács, I. et al. Quantitative absorbance spectroscopy with unpolarized light, part II: experimental evaluation and development of a protocol for quantitative analysis of mineral IR spectra. Am. Mineral. 93, 765–778 (2008)

    Article  ADS  Google Scholar 

  26. Bell, D. R., Ihinger, P. D. & Rossman, G. R. Quantitative analysis of trace OH in garnet and pyroxenes. Am. Mineral. 80, 465–474 (1995)

    Article  ADS  CAS  Google Scholar 

  27. Bell, D. R., Rossman, G. R., Maldener, J., Endisch, D. & Rauch, F. Hydroxide in olivine: a quantitative determination of the absolute amount and calibration of the IR spectrum. J. Geophys. Res. B 108 2105 10.1029/2001JB000679 (2003)

    Article  ADS  CAS  Google Scholar 

  28. Niida, K., Green, D. H., Yoshikawa, M. & Eggins, S. M. Dunite channels in the Horoman peridotites, Japan: textural and geochemical constraints on melt/fluid transport through the lithosphere. Geochim. Cosmochim. Acta 70, A445 (2006)

    Article  ADS  Google Scholar 

  29. Faul, U. H. & Jackson, I. N. S. Diffusion creep of dry, melt-free olivine. J. Geophys. Res. 112 B04204 10.1029/2006JB004586 (2007)

    Article  ADS  CAS  Google Scholar 

  30. Faul, U. H. Melt retention and segregation beneath mid-ocean ridges. Nature 410, 920–923 (2001)

    Article  ADS  CAS  Google Scholar 

Download references

Acknowledgements

We thank H. St C. O’Neill, J. Hermann and G. M. Yaxley for discussions, and F. Brink for comprehensive support at scanning electron microscopy (SEM) facilities. We appreciate the help of J. Blundy in the revision of the original manuscript. This research was supported by Australian Research Council grants to D.H.G., and to G. M. Yaxley and D.H.G. I.K. was supported by an A. E. Ringwood Memorial Scholarship, an Australian International Postgraduate Research Scholarship and a Marie Curie International Reintegration Grant (NAMS-230937). A.R. was supported by an Australian National University PhD Scholarship.

Author information

Authors and Affiliations

Authors

Contributions

D.H.G. initiated and planned the project, and made most of the SEM micro-analyses. W.O.H. carried out the high-pressure experimental work and prepared the experimental charges for SEM analysis. A.R. did some 6 GPa experiments, assisted in SEM analyses and compiled all the analyses. I.K. prepared the thin sections for FTIR analyses, performed the FTIR spectroscopy and processed the data. All authors contributed to the writing of the manuscript.

Corresponding author

Correspondence to David H. Green.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Information

This file contains Supplementary Figures 1-2 with legends and Supplementary Tables 3-4. (PDF 1023 kb)

PowerPoint slides

Rights and permissions

Reprints and permissions

About this article

Cite this article

Green, D., Hibberson, W., Kovács, I. et al. Water and its influence on the lithosphere–asthenosphere boundary. Nature 467, 448–451 (2010). https://doi.org/10.1038/nature09369

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nature09369

This article is cited by

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.

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