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Redox freezing and melting in the Earth’s deep mantle resulting from carbon–iron redox coupling

Abstract

Very low seismic velocity anomalies in the Earth’s mantle1,2 may reflect small amounts of melt present in the peridotite matrix, and the onset of melting in the Earth’s upper mantle is likely to be triggered by the presence of small amounts of carbonate3. Such carbonates stem from subducted oceanic lithosphere in part buried to depths below the 660-kilometre discontinuity and remixed into the mantle. Here we demonstrate that carbonate-induced melting may occur in deeply subducted lithosphere at near-adiabatic temperatures in the Earth’s transition zone and lower mantle. We show experimentally that these carbonatite melts are unstable when infiltrating ambient mantle and are reduced to immobile diamond when recycled at depths greater than 250 kilometres, where mantle redox conditions are determined by the presence of an (Fe,Ni) metal phase4,5,6. This ‘redox freezing’ process leads to diamond-enriched mantle domains in which the Fe0, resulting from Fe2+ disproportionation in perovskites and garnet, is consumed but the Fe3+ preserved. When such carbon-enriched mantle heterogeneities become part of the upwelling mantle, diamond will inevitably react with the Fe3+ leading to true carbonatite redox melting at 660 and 250 kilometres depth to form deep-seated melts in the Earth’s mantle.

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Figure 1: The solidus of carbonated peridotite.
Figure 2: Carbon speciation in natural mantle as a function of pressure, temperature and .
Figure 3: Carbonatitic redox freezing and redox melting caused by redox capacity changes in Earth’s mantle.

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References

  1. Forsyth, D. W. et al. Imaging the deep seismic structure beneath a mid-ocean ridge: the MELT experiment. Science 280, 1215–1218 (1998)

    Article  ADS  Google Scholar 

  2. Gu, Y. J., Lerner–Lamb, A. L., Dziewonskic, A. M. & Ekström, G. Deep structure and seismic anisotropy beneath the East Pacific Rise. Earth Planet. Sci. Lett. 232, 259–272 (2005)

    Article  ADS  CAS  Google Scholar 

  3. Dasgupta, R. & Hirschmann, M. M. Melting in the Earth's deep upper mantle caused by carbon dioxide. Nature 440, 659–662 (2006)

    Article  ADS  CAS  PubMed  Google Scholar 

  4. Ballhaus, C. Is the upper mantle metal-saturated? Earth Planet. Sci. Lett. 132, 75–86 (1995)

    Article  ADS  CAS  Google Scholar 

  5. Frost, D. J. et al. Experimental evidence for the existence of iron-rich metal in the Earth’s lower mantle. Nature 428, 409–412 (2004)

    Article  ADS  CAS  PubMed  Google Scholar 

  6. Rohrbach, A. et al. Metal saturation in the upper mantle. Nature 449, 456–458 (2007)

    Article  ADS  CAS  PubMed  Google Scholar 

  7. Allègre, C. J. & Turcotte, D. L. Implications of a two-component marble-cake mantle. Nature 323, 123–127 (1986)

    Article  ADS  Google Scholar 

  8. Hofmann, A. W. Mantle geochemistry: the message from oceanic volcanism. Nature 385, 219–229 (1997)

    Article  ADS  CAS  Google Scholar 

  9. Dalton, J. A. & Presnall, D. C. Carbonatitic melts along the solidus of model lherzolite in the system CaO–MgO–Al2O3–SiO2–CO2 from 3 to 7 GPa. Contrib. Mineral. Petrol. 131, 123–135 (1998)

    Article  ADS  CAS  Google Scholar 

  10. Ghosh, S., Ohtani, E., Litasov, K. D. & Terasaki, H. Solidus of carbonated peridotite from 10 to 20 GPa and origin of magnesiocarbonatite melt in the Earth’s deep mantle. Chem. Geol. 262, 17–28 (2009)

    Article  ADS  CAS  Google Scholar 

  11. Brey, G. P., Bulatov, V. K., Girnis, A. V. & Lahaye, Y. Experimental melting of carbonated peridotite at 6–10 GPa. J. Petrol. 49, 797–821 (2008)

    Article  ADS  CAS  Google Scholar 

  12. Litasov, K. D. & Ohtani, E. Solidus and phase relations of carbonated peridotite in the system CaO–Al2O3–MgO–SiO2–Na2O–CO2 to the lower mantle depths. Phys. Earth Planet. Inter. 177, 46–58 (2009)

    Article  ADS  Google Scholar 

  13. Woodland, A. B. & Koch, M. Variation in oxygen fugacity with depth in the upper mantle beneath the Kaapvaal craton, South Africa. Earth Planet. Sci. Lett. 214, 295–310 (2003)

    Article  ADS  CAS  Google Scholar 

  14. Frost, D. J. & McCammon, C. A. The redox state of the Earth's mantle. Annu. Rev. Earth Planet. Sci. 36, 389–420 (2008)

    Article  ADS  CAS  Google Scholar 

  15. Stagno, V. & Frost, D. J. Carbon speciation in the asthenosphere: experimental measurements of the redox conditions at which carbonate-bearing melts coexist with graphite or diamond in peridotite assemblages. Earth Planet. Sci. Lett. 300, 72–84 (2010)

    Article  ADS  CAS  Google Scholar 

  16. Gudmundsson, G. & Wood, B. J. Experimental tests of garnet peridotite oxygen barometry. Contrib. Mineral. Petrol. 119, 56–67 (1995)

    Article  ADS  CAS  Google Scholar 

  17. Eggler, D. H. & Baker, D. R. in High Pressure Research in Geophysics (eds Akimoto, S. & Manghnani, M. H.) 237–250 (Centre for Academic Publishing, 1982)

    Book  Google Scholar 

  18. O’Neill, H. et al. in Evolution of the Earth and Planets (eds Takahashi, E., Jeanloz, R. & Rubie, D. C.) 73–88 (Geophys. Monogr. 74, Int. Union Geol. Geophys./Am. Geophys. Union, 1993)

  19. Taylor, W. R. & Green, D. H. in Magmatic Processes and Physiochemical Principles (ed. Mysen, B. O.) 121–138 (Spec. Publ. No. 1, Geochem. Soc. USA, 1987)

    Google Scholar 

  20. Kohn, S. C. Solubility of H2O in nominally anhydrous mantle minerals using 1H MAS NMR. Am. Mineral. 81, 1523–1526 (1996)

    Article  ADS  CAS  Google Scholar 

  21. Keppler, H. & Bolfan–Casanova, N. in Water in Nominally Anhydrous Minerals (eds Keppler, H. & Smyth, J. R.) 193–230 (Reviews in Mineralogy and Geochemistry 62, Min. Soc. Am., 2006)

    Book  Google Scholar 

  22. Luth, R. W. in Mantle Petrology: Field Observations and High Pressure Experimentation: A Tribute to Francis R. (Joe) Boyd (eds Fei, Y., Bertka, C. M. & Mysen, B. O.) 297–316 (Geochemical Society, 1999)

    Google Scholar 

  23. Ringwood, A. E. The pyroxene–garnet transformation in the Earth's mantle. Earth Planet. Sci. Lett. 2, 255–263 (1967)

    Article  ADS  CAS  Google Scholar 

  24. Woodland, A. B. & O’Neill, H. Thermodynamic data for Fe-bearing phases obtained using noble metal alloys as redox sensors. Geochim. Cosmochim. Acta 61, 4359–4366 (1997)

    Article  ADS  CAS  Google Scholar 

  25. Dasgupta, R. & Hirschmann, M. M. The deep carbon cycle and melting in Earth's interior. Earth Planet. Sci. Lett. 298, 1–13 (2010)

    Article  ADS  CAS  Google Scholar 

  26. Lord, O. T., Walter, M. J., Dasgupta, R., Walker, D. & Clark, S. M. Melting in the Fe–C system to 70 GPa. Earth Planet. Sci. Lett. 284, 157–167 (2009)

    Article  ADS  CAS  Google Scholar 

  27. Minarik, W. G. & Watson, E. B. Interconnectivity of carbonate melt at low melt fraction. Earth Planet. Sci. Lett. 133, 423–437 (1995)

    Article  ADS  Google Scholar 

  28. Hunter, R. H. & McKenzie, D. The equilibrium geometry of carbonate melts in rocks of mantle composition. Earth Planet. Sci. Lett. 92, 347–356 (1989)

    Article  ADS  CAS  Google Scholar 

  29. Stachel, T., Brey, G. P. & Harris, J. W. Inclusions in sublithospheric diamonds: glimpses of deep earth. Elements 1, 73–78 (2005)

    Article  CAS  Google Scholar 

  30. Bagdassarov, N., Solferino, G., Golabek, G. J. & Schmidt, M. W. Centrifuge assisted percolation of Fe–S melts in partially molten peridotite: time constraints for planetary core formation. Earth Planet. Sci. Lett. 288, 84–95 (2009)

    Article  ADS  CAS  Google Scholar 

  31. Connolly, J. A. D., Schmidt, M. W., Solferino, G. & Bagdassarov, N. Permeability of asthenospheric mantle and melt extraction rates at mid-ocean ridges. Nature 462, 209–212 (2009)

    Article  ADS  CAS  PubMed  Google Scholar 

  32. Stixrude, L. & Lithgow-Bertelloni, C. Influence of phase transformations on lateral heterogeneity and dynamics in Earth's mantle. Earth Planet. Sci. Lett. 263, 45–55 (2007)

    Article  ADS  CAS  Google Scholar 

  33. Campbell, A. J. et al. High pressure effects on the iron–iron oxide and nickel–nickel oxide oxygen fugacity buffers. Earth Planet. Sci. Lett. 286, 556–564 (2009)

    Article  ADS  CAS  Google Scholar 

  34. Palme, H. & O’Neill, H. in The Mantle and The Core Vol 2. (ed. Carlson, R. W.) 1–38 (Elsevier-Pergamon, 2003)

    Google Scholar 

  35. Stewart, A. J., van Westrenen, W., Schmidt, M. W. & Melekhova, E. Effect of gasketing and assembly design: a novel 10/3.5 mm multi-anvil assembly reaching perovskite pressures. High Press. Res. 26, 293–299 (2006)

    Article  ADS  CAS  Google Scholar 

  36. Campbell, A. J . et al. Pressure–volume–temperature studies of metal–oxide pairs. In COMPRES Annual Meeting (2007); 〈www.geol.umd.edu/ajc/Posters/CampbellCOMPRES2007poster.pdf〉.

    Google Scholar 

  37. Predel, B . Fe–Ni in The Landolt–Börnstein Database (ed. Madelung, O.) (Springer Materials, 1995); doi:10.1007/10474837_1321.

  38. Wang, J., Lu, X.-G., Sundman, B. & Su, X. Thermodynamic assessment of the Au–Ni system. Comput. Coupling Phase Diagr. Thermochem. 29, 263–268 (2005)

    Article  CAS  Google Scholar 

  39. Frost, D. J. Fe2+–Mg partitioning between garnet, magnesiowüstite and (Mg,Fe)2SiO4 phases of the transition zone. Am. Mineral. 88, 387–397 (2003)

    Article  ADS  CAS  Google Scholar 

  40. McCammon, C. A., Peyronneau, J. & Poirier, J.-P. Low ferric iron content of (Mg,Fe)O at high pressures and temperatures. Geophys. Res. Lett. 25, 1589–1592 (1998)

    Article  ADS  CAS  Google Scholar 

  41. Frost, D. J., Langenhorst, F. & van Aken, P. Fe–Mg partitioning between ringwoodite and magnesiowüstite and the effect of pressure, temperature and oxygen fugacity. Phys. Chem. Miner. 28, 455–470 (2001)

    Article  ADS  CAS  Google Scholar 

  42. Frost, D. J. & Langenhorst, F. The effect of Al2O3 on Fe–Mg partitioning between magnesiowüstite and magnesium silicate perovskite. Earth Planet. Sci. Lett. 199, 227–241 (2002)

    Article  ADS  CAS  Google Scholar 

  43. Seifert, S. & O’Neill, H. Experimental determination of activity–composition relations in Ni2SiO4–Mg2SiO4 and Co2SiO4–Mg2SiO4 olivine solid solutions at 1200 K and 0.1 MPa and 1573 K and 0.5 GPa. Geochim. Cosmochim. Acta 51, 97–104 (1987)

    Article  ADS  CAS  Google Scholar 

  44. O’Neill, H., St. C, Canil, D. & Rubie, D. C. Oxide metal equilibria to 2500 °C and 25 GPa: implications for core formation and the light component in the Earth’s core. J. Geophys. Res. 103, 12239–12260 (1998)

    Article  ADS  Google Scholar 

  45. Frost, D. J. The structure and sharpness of (Mg,Fe)2SiO4 phase transformations in the transition zone. Earth Planet. Sci. Lett. 216, 313–328 (2003b)

    Article  ADS  CAS  Google Scholar 

  46. Hirschmann, M. Thermodynamics of multicomponent olivines and the solution properties of (Ni,Mg,Fe)2SiO4 and (Ca,Mg,Fe)2SiO4 olivines. Am. Mineral. 76, 1232–1248 (1991)

    CAS  Google Scholar 

  47. Hirschmann, M. M. & Ghiorso, M. S. Activities of nickel, cobalt and manganese silicate in magmatic liquids and application to olivine/liquid and to silicate/melt partitioning. Geochim. Cosmochim. Acta 58, 4109–4126 (1994)

    Article  ADS  CAS  Google Scholar 

  48. O’Neill, H. S. C. & Wall, V. J. The olivine-orthopyroxene-spinel oxygen geobarometer, the nickel precipitation curve, and the oxygen fugacity of the Earth's upper mantle. J. Petrol. 28, 1169–1191 (1987)

    Article  ADS  Google Scholar 

  49. Barin, I., Sauert, F., Schultze-Rhonhof, E. & Sheng, W. S. Thermochemical Data of Pure Substances Parts I and II (Weinheim, 1989)

    Google Scholar 

  50. Wood, B. J. & Fraser, D. G. Elementary Thermodynamics for Geologists (Oxford Univ. Press, 1976)

    Google Scholar 

  51. Mukhopadhyay, B., Basu, S. & Holdaway, M. J. A discussion of Margules-type formulations for multicomponent solutions with a generalized approach. Geochim. Cosmochim. Acta 57, 277–283 (1993)

    Article  ADS  CAS  Google Scholar 

  52. Swartzendruber, L. J. The Fe–Ir (iron–iridium) system. Bull. Alloy Phase Diagrams 5, 48–52 (1984)

    Article  CAS  Google Scholar 

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Acknowledgements

Discussions with P. Ulmer, U. Mann and C. Ballhaus stimulated this work. Comments and suggestions from T. Stachel improved the manuscript. Financial support by Swiss National Science Foundation (SNSF) grant 2-777-86-06 is acknowledged.

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M.W.S. and A.R. designed this project and M.W.S. obtained its funding. Experiments, analytical work and f O 2 calculations were done by A.R.; both authors contributed equally to all other parts.

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Correspondence to Arno Rohrbach.

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The authors declare no competing financial interests.

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Rohrbach, A., Schmidt, M. Redox freezing and melting in the Earth’s deep mantle resulting from carbon–iron redox coupling. Nature 472, 209–212 (2011). https://doi.org/10.1038/nature09899

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