Skip to main content

Thank you for visiting 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.

Primary carbonatite melt from deeply subducted oceanic crust


Partial melting in the Earth’s mantle plays an important part in generating the geochemical and isotopic diversity observed in volcanic rocks at the surface1. Identifying the composition of these primary melts in the mantle is crucial for establishing links between mantle geochemical ‘reservoirs’ and fundamental geodynamic processes2. Mineral inclusions in natural diamonds have provided a unique window into such deep mantle processes3,4,5,6,7,8. Here we provide experimental and geochemical evidence that silicate mineral inclusions in diamonds from Juina, Brazil, crystallized from primary and evolved carbonatite melts in the mantle transition zone and deep upper mantle. The incompatible trace element abundances calculated for a melt coexisting with a calcium-titanium-silicate perovskite inclusion indicate deep melting of carbonated oceanic crust, probably at transition-zone depths. Further to perovskite, calcic-majorite garnet inclusions record crystallization in the deep upper mantle from an evolved melt that closely resembles estimates of primitive carbonatite on the basis of volcanic rocks. Small-degree melts of subducted crust can be viewed as agents of chemical mass-transfer in the upper mantle and transition zone, leaving a chemical imprint of ocean crust that can possibly endure for billions of years.

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

Relevant articles

Open Access articles citing this article.

Access options

Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1: Mineral chemistry and geobarometry of perovskite and garnet mineral inclusions in Juina diamonds.
Figure 2: Subsolidus and melting phase relations in the compositional join CaTiO3–CaSiO3–MgSiO3.
Figure 3: Relative compatibility diagrams showing trace element abundances of mineral inclusions and calculated coexisting melts.
Figure 4: Relative compatibility diagrams showing trace element abundances of model primitive carbonatites normalized to primitive mantle.


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

    ADS  CAS  Article  Google Scholar 

  2. Zindler, A. & Hart, S. R. Chemical geodynamics. Annu. Rev. Earth Planet. Sci. 14, 493–571 (1986)

    ADS  CAS  Article  Google Scholar 

  3. Haggerty, S. E. in Mantle Petrology: Field Observations and High Pressure Experimentation (eds Fei, Y., Bertka, C. M. & Mysen, B. O.) 105–123 (Geochemical Society Special Publications, 1999)

    Google Scholar 

  4. Harte, B. & Harris, J. W. Lower mantle mineral association preserved in diamonds. Miner. Mag. A 58, 384–385 (1994)

    Article  Google Scholar 

  5. Harte, B., Harris, J. W., Hutchison, M. T., Watt, G. R. & Wilding, M. C. in Mantle Petrology: Field observations and High Pressure Experimentation (eds Fei, Y., Bertka, C. M. & Mysen, B. O.) 125–153 (Geochemical Society Special Publications, Houston, 1999)

    Google Scholar 

  6. Kaminsky, F. et al. Superdeep diamonds from the Juina area, Mato Grosso State, Brazil. Contrib. Mineral. Petrol. 140, 734–753 (2001)

    ADS  CAS  Article  Google Scholar 

  7. Stachel, T. Diamonds from the asthenosphere and the transition zone. Eur. J. Mineral. 13, 883–892 (2001)

    ADS  CAS  Article  Google Scholar 

  8. Tappert, R. et al. Subducting oceanic crust: The source of deep diamonds. Geology 33, 565–568 (2005)

    ADS  CAS  Article  Google Scholar 

  9. Brenker, F. E. et al. Detection of a Ca-rich lithology in the Earth’s deep (>300 km) convecting mantle. Earth Planet. Sci. Lett. 236, 579–587 (2005)

    ADS  CAS  Article  Google Scholar 

  10. Hayman, P. C., Kopylova, M. G. & Kaminsky, F. V. Lower mantle diamonds from Rio Soriso (Juina area, Mato Grosso, Brazil). Contrib. Mineral. Petrol. 149, 430–445 (2005)

    ADS  CAS  Article  Google Scholar 

  11. Bulanova, G. P. The formation of diamond. J. Geochem. Exp. 53, 1–23 (1995)

    CAS  Article  Google Scholar 

  12. Brenker, F. E. et al. Carbonates from the lower part of transition zone or even the lower mantle. Earth Planet. Sci. Lett. 260, 1–9 (2007)

    ADS  CAS  Article  Google Scholar 

  13. Kubo, A., Suzuki, T. & Akaogi, M. High pressure phase equilibria in the system CaTiO3-CaSiO3: stability of perovskite solid solutions. Phys. Chem. Mineral. 24, 488–494 (1997)

    ADS  CAS  Article  Google Scholar 

  14. Stachel, T., Harris, J. W., Brey, G. & Joswig, W. Kankan diamonds (Guinea) II: lower mantle inclusion paragenesis. Contrib. Mineral. Petrol. 140, 16–27 (2000)

    ADS  CAS  Article  Google Scholar 

  15. Hirose, K. & Fei, Y. Subsolidus and melting phase relations of basaltic composition in the uppermost lower mantle. Geochim. Cosmochim. Acta 66, 2099–2108 (2002)

    ADS  CAS  Article  Google Scholar 

  16. Hirose, K., Shimizu, N., vanWestrenan, W. & Fei, Y. Trace element partitioning in Earth’s lower mantle and implications for geochemical consequences of partial melting at the core–mantle boundary. Phys. Earth Planet. Inter. 146, 249–260 (2004)

    ADS  CAS  Article  Google Scholar 

  17. Irifune, T. & Ringwood, A. E. Phase transformations in subducted oceanic crust and buoyancy relationships at depths of 600–800 km in the mantle. Earth Planet. Sci. Lett. 117, 101–110 (1993)

    ADS  CAS  Article  Google Scholar 

  18. McDonough, W. F. & Sun, S.-s. The composition of the Earth. Chem. Geol. 120, 223–253 (1995)

    ADS  CAS  Article  Google Scholar 

  19. Safonov, O. G., Perchuk, L. L. & Litvin, Y. A. Melting relations in the chloride–carbonate–silicate systems at high-pressure and the model for formation of alkalic diamond–forming liquids in the upper mantle. Earth Planet. Sci. Lett. 253, 112–128 (2007)

    ADS  CAS  Article  Google Scholar 

  20. Arima, M., Kozai, Y. & Akaishi, M. Diamond nucleation and growth by reduction of carbonate melts under high-pressure and high-temperature conditions. Geology 30, 691–694 (2002)

    ADS  CAS  Article  Google Scholar 

  21. Keshav, S., Gudfinnsson, G. & Presnall, D. Majoritic-garnets and clinopyroxenes in cratonic diamonds: Precipitates from CO2-rich melts. Proc. 11th Int. Conf. EMPG abstr. 36 (2006)

  22. Corgne, A. & Wood, B. J. CaSiO3 and CaTiO3 perovskite–melt partitioning of trace elements: implications for gross mantle differentiation. Geophys. Res. Lett. 29 10.1029/2001GL014398 (2002)

  23. Brenan, J. M., Shaw, H. F., Ryerson, F. J. & Phinney, D. L. Mineral-aqueous fluid partitioning of trace elements at 900°C and 2.0 GPa: Constraints on the trace element chemistry of mantle and deep crustal fluids. Geochim. Cosmochim. Acta 59, 3331–3350 (1995)

    ADS  CAS  Article  Google Scholar 

  24. Kessel, R., Schmidt, M., Ulmer, P. & Pettke, T. Trace element signature of subduction-zone fluids, melts and supercritical liquids at 120–180 km depth. Nature 437, 724–727 (2005)

    ADS  CAS  Article  Google Scholar 

  25. Manning, C. E. The chemistry of subduction-zone fluids. Earth Planet. Sci. Lett. 223, 1–16 (2004)

    ADS  CAS  Article  Google Scholar 

  26. Coltorti, M., Bonadiman, C., Hinton, R. W., Siena, F. & Upton, B. G. J. Carbonatite metasomatism of the oceanic upper mantle: Evidence from clinopyroxenes and glasses in ultramafic xenoliths of Grande Comore, Indian Ocean. J. Petrol. 40, 133–165 (1999)

    ADS  CAS  Article  Google Scholar 

  27. Harmer, R. E. & Gittins, J. The case for primary, mantle-derived carbonatite magma. J. Petrol. 39, 1895–1903 (1998)

    ADS  CAS  Article  Google Scholar 

  28. Hauri, E., Shimizu, N., Dieu, J. J. & Hart, S. R. Evidence for hotspot-related carbonatite metasomatism in the oceanic upper mantle. Nature 365, 221–227 (1993)

    ADS  CAS  Article  Google Scholar 

  29. Ionov, D. A. Trace element composition of mantle-derived carbonates and coexisting phases in peridotite xenoliths from alkali basalts. J. Petrol. 39, 1931–1941 (1998)

    ADS  CAS  Article  Google Scholar 

  30. Kogarko, L. N. Geochemical characteristics of oceanic carbonatites from Cape Verde Islands. S. Afr. J. Geol. 96, 119–125 (1993)

    CAS  Google Scholar 

  31. Stachel, T., Brey, G. & Harris, J. W. Kankan diamonds (Guinea) I: from the lithosphere down to the transition zone. Contrib. Mineral. Petrol. 140, 1–15 (2000)

    ADS  CAS  Article  Google Scholar 

  32. Dasgupta, R., Hirschmann, M. M. & Withers, A. C. Deep global cycling of carbon constrained by the solidus of anhydrous, carbonated eclogite under upper mantle conditions. Earth Planet. Sci. Lett. 227, 73–85 (2004)

    ADS  CAS  Article  Google Scholar 

  33. Hirose, K., Fei, Y., Ma, Y. & Mao, H.-K. The fate of subducted basaltic crust in the Earth’s lower mantle. Nature 397, 53–56 (1999)

    ADS  CAS  Article  Google Scholar 

  34. Walter, M. J. et al. Subsolidus phase relations and perovskite compressibility in the system MgO-AlO1. 5-SiO2 with implications for Earth’s lower mantle. Earth Planet. Sci. Lett. 248, 77–89 (2006)

    ADS  CAS  Article  Google Scholar 

  35. Walter, M. J. & Koga, K. T. The effects of chromatic dispersion on temperature measurement in the laser-heated diamond anvil cell. Phys. Earth Planet. Inter. 143–144, 541–558 (2004)

    ADS  Article  Google Scholar 

Download references


Diamond samples from Collier 4 were collected by Rio Tinto (Rio Tinto Desenvolvimentos Minerais Ltda) in 1994. We thank Rio Tinto for access to the collection and J. Pickles for technical assistance. This work was supported by an NERC grant to M.J.W. Experiments by L.S.A. at Bayerisches Geoinstitut were supported by the Marie Curie 6th Framework Programme. Synchrotron experiments at Synchrotron Radiation Source, Daresbury Laboratory, UK, and at the Advanced Light Source, Berkeley, USA, were supported by awards to M.J.W. Trace element analyses at the NERC Edinburgh Ion Microprobe Facility were supported by an award to M.J.W.

Author Contributions M.J.W., G.P.B, J.D.B. and C.B.S. formulated the project. M.J.W., L.S.A., S.K., G.G., O.T.L., A.R.L. and S.M.C. were responsible for experimental and analytical data collection. G.P.B. was responsible for diamond sample preparation. L.G. processed the kimberlite to recover diamonds and selected inclusion-bearing stones for the project. M.J.W. wrote the manuscript with assistance from G.P.B., L.S.A., S.K., J.D.B., A.R.L. and C.B.S.

Author information

Authors and Affiliations


Corresponding author

Correspondence to M. J. Walter.

Supplementary information

Supplementary information

The file contains Supplementary Tables 1 and 2. Supplementary Table 1 provides major and trace element analyses of perovskite and majorite mineral inclusions in diamonds J1, J9 and J10 from Juina, Brazil. Supplementary Table 2 provides the trace element abundances of calculated melts that can coexist with the mineral inclusions based on the data in Supplemental Table 1. Also provided are mineral/melt partition coefficients used in the calculations and a description of the sources of the coefficients. (PDF 183 kb)

PowerPoint slides

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Walter, M., Bulanova, G., Armstrong, L. et al. Primary carbonatite melt from deeply subducted oceanic crust. Nature 454, 622–625 (2008).

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI:

This article is cited by


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.


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