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Extreme redox variations in a superdeep diamond from a subducted slab

Nature volume 613, pages 85–89 (2023)Cite this article

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Abstract

The introduction of volatile-rich subducting slabs to the mantle may locally generate large redox gradients, affecting phase stability, element partitioning and volatile speciation1. Here we investigate the redox conditions of the deep mantle recorded in inclusions in a diamond from Kankan, Guinea. Enstatite (former bridgmanite), ferropericlase and a uniquely Mg-rich olivine (Mg# 99.9) inclusion indicate formation in highly variable redox conditions near the 660 km seismic discontinuity. We propose a model involving dehydration, rehydration and dehydration in the underside of a warming slab at the transition zone–lower mantle boundary. Fluid liberated by dehydration in a crumpled slab, driven by heating from the lower mantle, ascends into the cooler interior of the slab, where the H2O is sequestered in new hydrous minerals. Consequent fractionation of the remaining fluid produces extremely reducing conditions, forming Mg-end-member ringwoodite. This fractionating fluid also precipitates the host diamond. With continued heating, ringwoodite in the slab surrounding the diamond forms bridgmanite and ferropericlase, which is trapped as the diamond grows in hydrous fluids produced by dehydration of the warming slab.

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Fig. 1: Room temperature Mössbauer spectrum of the ferropericlase inclusion in diamond KK203 showing that its Fe3+/ΣFe is negligible and indicating fO2 conditions near the IW buffer.
Fig. 2: Schematic pressure–temperature plot illustrating processes in a warming, hydrated, subducted slab over time and the relationships between ringwoodite, ferropericlase and bridgmanite.
Fig. 3: Diamond growth events through a schematic cross-section of Earth.

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Data availability

The original reflection data for olivine in KK203 diamond and Supplementary Tables 1–3 have been deposited at EarthChem  (https://doi.org/10.26022/IEDA/112541).

References

  1. Palot, M., Pearson, D. G., Stern, R. A., Stachel, T. & Harris, J. W. Isotopic constraints on the nature and circulation of deep mantle C–H–O–N fluids: carbon and nitrogen systematics within ultra-deep diamonds from Kankan (Guinea). Geochim. Cosmochim. Acta 139, 26–46 (2014).

    Article  ADS  CAS  Google Scholar 

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

    Article  CAS  Google Scholar 

  3. Walter, M. J. et al. Primary carbonatite melt from deeply subducted oceanic crust. Nature 454, 622–625 (2008).

    Article  ADS  CAS  Google Scholar 

  4. Harte, B., Harris, J. W., Hutchison, M. T., Watt, G. R. & Wilding, M. C. 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.) 125–153 (The Geochemical Society, 1999).

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

    Article  ADS  CAS  Google Scholar 

  6. Smith, E. M. et al. Blue boron-bearing diamonds from Earth’s lower mantle. Nature 560, 84–87 (2018).

    Article  ADS  CAS  Google Scholar 

  7. Stachel, T., Harris, J. W., Aulbach, S. & Deines, P. Kankan diamonds (Guinea) III: δ13C and nitrogen characteristics of deep diamonds. Contrib. Mineral. Petrol. 142, 465–475 (2002).

    Article  ADS  CAS  Google Scholar 

  8. Regier, M. E. et al. The lithospheric-to-lower-mantle carbon cycle recorded in superdeep diamonds. Nature 585, 234–238 (2020).

    Article  CAS  Google Scholar 

  9. Thomson, A. R., Walter, M. J., Kohn, S. C. & Brooker, R. A. Slab melting as a barrier to deep carbon subduction. Nature 529, 76–79 (2016).

    Article  ADS  CAS  Google Scholar 

  10. 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 

  11. Ringwood, A. E. Phase transformations and differentiation in subducted lithosphere: implications for mantle dynamics, basalt petrogenesis, and crustal evolution. J. Geol. 90, 611–643 (1982).

    Article  ADS  CAS  Google Scholar 

  12. Brey, G. P., Bulatov, V., Girnis, A., Harris, J. W. & Stachel, T. Ferropericlase—a lower mantle phase in the upper mantle. Lithos 77, 655–663 (2004).

    Article  ADS  CAS  Google Scholar 

  13. Nestola, F. et al. New accurate elastic parameters for the forsterite-fayalite solid solution. Am. Mineral. 96, 1742–1747 (2011).

    Article  ADS  CAS  Google Scholar 

  14. Poe, B. T., Romano, C., Nestola, F. & Smyth, J. R. Electrical conductivity anisotropy of dry and hydrous olivine at 8 GPa. Phys. Earth Planet. In. 181, 103–111 (2010).

    Article  ADS  CAS  Google Scholar 

  15. Nestola, F. et al. First crystal structure determination of olivine in diamond: composition and implications for provenance in the Earth’s mantle. Earth Planet. Sci. Lett. 305, 249–255 (2011).

    Article  ADS  CAS  Google Scholar 

  16. Angel, R. J., Alvaro, M. & Nestola, F. 40 years of mineral elasticity: a critical review and a new parameterisation of equations of state for mantle olivines and diamond inclusions. Phys. Chem. Mineral. 45, 95–113 (2018).

    Article  ADS  CAS  Google Scholar 

  17. Angel, R. J., Alvaro, M., Nestola, F. & Mazzucchelli, M. L. Diamond thermoelastic properties and implications for determining the pressure of formation of diamond–inclusion systems. Russian Geol. Geophys. 56, 211–220 (2015).

    Article  Google Scholar 

  18. Angel, R. J., Mazzucchelli, M. L., Alvaro, M. & Nestola, F. EosFit-Pinc: a simple GUI for host–inclusion elastic thermobarometry. Am. Mineral. 102, 1957–1960 (2017).

    Article  ADS  Google Scholar 

  19. Katsura, T., Yoneda, A., Yamazaki, D., Yoshino, T. & Ito, E. Adiabatic temperature profile in the mantle. Phys. Earth Planet. Int. 183, 212–218 (2010).

    Article  ADS  CAS  Google Scholar 

  20. Hasterok, D. & Chapman, D. S. Heat production and geotherms for the continental lithosphere. Earth Planet. Sci. Lett. 307, 59–70 (2011).

    Article  ADS  CAS  Google Scholar 

  21. Cayzer, N. J., Odake, S., Harte, B. & Kagi, H. Plastic deformation of lower mantle diamonds by inclusion phase transformations. Eur. J. Mineral. 20, 333–339 (2008).

    Article  ADS  CAS  Google Scholar 

  22. Wood, B. J. Phase transformations and partitioning relations in peridotite under lower mantle conditions. Earth Planet. Sci. Lett. 174, 341–354 (2000).

    Article  ADS  CAS  Google Scholar 

  23. Davies, R. M., Griffin, W. L., O’Reilly, S. Y. & Doyle, B. J. Mineral inclusions and geochemical characteristics of microdiamonds from the DO27, A154, A21, A418, DO18, DD17 and Ranch Lake kimberlites at Lac de Gras, Slave Craton, Canada. Lithos 77, 39–55 (2004).

    Article  ADS  CAS  Google Scholar 

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

  25. Tappert, R., Stachel, T., Harris, J. W., Shimizu, N. & Brey, G. P. Mineral inclusions in diamonds from the Panda kimberlite, Slave province, Canada. Eur. J. Miner. 17, 423–440 (2005).

    Article  CAS  Google Scholar 

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

  27. Regier, M. E. et al. An oxygen isotope test for the origin of Archean mantle roots. Geochemical Perspect. Lett. 9, 6–10 (2018).

    Article  Google Scholar 

  28. Vance, J. A. & Dungan, M. A. Formation of peridotites by deserpentinization in the Darrington and Sultan areas, Cascade Mountains, Washington. Bull. Geol. Soc. Am. 88, 1497–1508 (1977).

    Article  CAS  Google Scholar 

  29. Kitamura, M., Shen, B., Banno, S. & Morimoto, N. Fine textures of laihunite, a nonstoichiometric distorted olivine-type mineral. Am. Mineral. 69, 154–160 (1984).

    CAS  Google Scholar 

  30. Blondes, M. S., Brandon, M. T., Reiners, P. W., Page, F. Z. & Kita, N. T. Generation of forsteritic olivine (Fo99·8) by subsolidus oxidation in basaltic flows. J. Petrol. 53, 971–984 (2012).

    Article  ADS  CAS  Google Scholar 

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

    Article  ADS  CAS  Google Scholar 

  32. Shahar, A. et al. High-temperature Si isotope fractionation between iron metal and silicate. Geochim. Cosmochim. Acta 75, 7688–7697 (2011).

    Article  ADS  CAS  Google Scholar 

  33. Schmidt, M. W., Gao, C., Golubkova, A., Rohrbach, A. & Connolly, J. A. Natural moissanite (SiC) – a low temperature mineral formed from highly fractionated ultra-reducing COH-fluids. Prog. Earth Planet. Sci. 1, 27 (2014).

    Article  Google Scholar 

  34. Rohrbach, A. & Schmidt, M. W. Redox freezing and melting in the Earth’s deep mantle resulting from carbon–iron redox coupling. Nature 472, 209–212 (2011).

    Article  ADS  CAS  Google Scholar 

  35. Ryabchikov, I. D. & Kaminsky, F. V. Oxygen potential of diamond formation in the lower mantle. Geol. Ore Depos. 55, 1–12 (2013).

    Article  ADS  Google Scholar 

  36. McCammon, C. A., Stachel, T. & Harris, J. W. Iron oxidation state in lower mantle mineral assemblages II. Inclusions in diamonds from Kankan, Guinea. Earth Planet. Sci. Lett. 222, 423–434 (2004).

    Article  ADS  CAS  Google Scholar 

  37. Otsuka, K., Longo, M., McCammon, C. A. & Karato, S. Ferric iron content of ferropericlase as a function of composition, oxygen fugacity, temperature and pressure: implications for redox conditions during diamond formation in the lower mantle. Earth Planet. Sci. Lett. 365, 7–16 (2013).

    Article  ADS  CAS  Google Scholar 

  38. Shirey, S. B., Wagner, L. S., Walter, M. J., Pearson, D. G. & van Keken, P. E. Slab transport of fluids to deep focus earthquake depths – thermal modeling constraints and evidence from diamonds. AGU Adv. 2, e2020AV000304 (2021).

    Article  ADS  Google Scholar 

  39. Van der Hist, R., Engdahl, R., Spakman, W. & Nolet, G. Tomographic imaging of subducted lithosphere below northwest Pacific island arcs. Nature 353, 37–43 (1991).

    Article  ADS  Google Scholar 

  40. Billen, M. I. Deep slab seismicity limited by rate of deformation in the transition zone. Sci. Adv. 6, eaaz7692 (2020).

    Article  ADS  Google Scholar 

  41. Pearson, D. G. et al. Hydrous mantle transition zone indicated by ringwoodite included within diamond. Nature 507, 221–224 (2014).

    Article  ADS  CAS  Google Scholar 

  42. Zhu, F., Li, J., Liu, J., Dong, J. & Liu, Z. Metallic iron limits silicate hydration in Earth’s transition zone. Proc. Natl Acad. Sci. 116, 22526–22530 (2019).

    Article  ADS  CAS  Google Scholar 

  43. Van der Meer, D. G., van Hinsbergen, D. J. J. & Spakman, W. Atlas of the underworld: slab remnants in the mantle, their sinking history, and a new outlook on lower mantle viscosity. Tectonophysics 723, 309–448 (2018).

    Article  ADS  Google Scholar 

  44. Harte, B. Diamond formation in the deep mantle: the record of mineral inclusions and their distribution in relation to mantle dehydration zones. Miner. Mag. 74, 189–215 (2010).

    Article  CAS  Google Scholar 

  45. Moussallam, Y. et al. Mantle plumes are oxidised. Earth Planet. Sci. Lett. 527, 115798 (2019).

    Article  CAS  Google Scholar 

  46. Kaminsky, F. V. et al. Oxidation potential in the Earth’s lower mantle as recorded by ferropericlase inclusions in diamond. Earth Planet. Sci. Lett. 417, 49–56 (2015).

    Article  ADS  CAS  Google Scholar 

  47. Kiseeva, E. S. et al. Oxidized iron in garnets from the mantle transition zone. Nat. Geosci. 11, 144–147 (2018).

    Article  ADS  CAS  Google Scholar 

  48. Kawamoto, T. Hydrous phase stability and partial melt chemistry in H2O-saturated KLB-1 peridotite up to the uppermost lower mantle conditions. Phys. Earth Planet. Inter. 143, 387–395 (2004).

    Article  ADS  Google Scholar 

  49. Wenz, M. D. et al. Fast identification of mineral inclusions in diamond at GSECARS using synchrotron X-ray microtomography, radiography and diffraction. J. Synchrotron Radiat. 26, 1763–1768 (2019).

    Article  CAS  Google Scholar 

  50. Golubkova, A., Schmidt, M. W. & Connolly, J. A. D. Ultra-reducing conditions in average mantle peridotites and in podiform chromitites: a thermodynamic model for moissanite (SiC) formation. Contrib. Mineral. Petrol. 171, 41 (2016).

  51. Holland, T. J. B. & Powell, R. An improved and extended internally consistent thermodynamic dataset for phases of petrological interest, involving a new equation of state for solids. J. Metamorph. Geol. 29, 333–383 (2011).

    Article  ADS  CAS  Google Scholar 

  52. Smith, E. M. et al. Heavy iron in large gem diamonds traces deep subduction of serpentinized ocean floor. Sci. Adv. 7, eabe9773 (2021).

    Article  ADS  CAS  Google Scholar 

  53. Fichtner, C. E., Schmidt, M. W., Liebske, C., Bouvier, A. S. & Baumgartner, L. P. Carbon partitioning between metal and silicate melts during Earth accretion. Earth Planet. Sci. Lett. 554, 116659 (2021).

  54. Wade, J. & Wood, B. J. Core formation and the oxidation state of the Earth. Earth Planet. Sci. Lett. 236, 78–95 (2005).

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Acknowledgements

This research used resources of the Advanced Photon Source, a US Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357. We acknowledge the support of GeoSoilEnviroCARS (Sector 13), which is supported by the US National Science Foundation (NSF) – Earth Sciences (EAR-1128799), and the Department of Energy, Geosciences (DE-FG02-94ER14466), and staff scientists M. Newville, T. Lanzirotti and M. Rivers. S.D.J. acknowledges support from NSF grant no. EAR-1853521. NSERC Discovery grants to R.W.L., D.G.P. and T.S. funded aspects of this research. The authors acknowledge A. Rohrbach and K. Kiseeva for very valuable comments that prompted a re-think of our fO2 estimate and formation model.

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Authors and Affiliations

  1. Department of Geosciences, University of Padova, Padova, Italy

    Fabrizio Nestola

  2. Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, Canada

    Margo E. Regier, Robert W. Luth, D. Graham Pearson, Thomas Stachel & Chiara Anzolini

  3. Bayerisches Geoinstitüt, University of Bayreuth, Bayreuth, Germany

    Catherine McCammon

  4. Department of Earth and Planetary Sciences, Northwestern University, Evanston, IL, USA

    Michelle D. Wenz & Steven D. Jacobsen

  5. Department of Earth Sciences, University of Firenze, Firenze, Italy

    Luca Bindi

  6. School of Geographical and Earth Sciences, University of Glasgow, Glasgow, UK

    Jeffrey W. Harris

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Contributions

M.E.R., C.A. and F.N. collected and interpreted the XRD data. M.E.R. characterized the inclusions by EPMA and Raman spectroscopy. F.N. and M.E.R. wrote the original manuscript. R.W.L. and T.S. developed the diamond growth model. F.N. and L.B performed the geobarometric calculations on olivine. C.M. characterized the inclusions by Mössbauer spectroscopy. M.D.W., M.E.R. and S.D.J. conducted tomographic image collection and analyses. R.W.L. and M.E.R. did the fO2 calculations. J.W.H. provided the diamond and helped describe and break the sample. F.N., M.R. and D.G.P. wrote the original manuscript. All coauthors improved interpretations and provided editing.

Corresponding author

Correspondence to Fabrizio Nestola.

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Nature thanks Kate Kiseeva and Arno Rohrbach for their contribution to the peer review of this work.

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Extended data figures and tables

Extended Data Fig. 1 Raman spectrum of enstatite measured in diamond KK203 (in blue solid line).

Reference spectrum of enstatite is in solid red line (RRUFF ID: R070641). The data reduction software is OMNIC 9 (Thermo Fisher Scientific Inc.).

Extended Data Fig. 2 X-ray tomographic image of KK203, collected at GSECARS, showing no cracks leading to inclusions.

The entire diamond could not fit into the field of view.

Extended Data Fig. 3 Calculated values of log fO2 relative to the IW buffer at 10, 15, and 20 GPa and 1,200, 1,400, and 1,800 °C necessary to stabilize a (Mg,Fe)2SiO4 polymorph with Mg# = 99.9.

The different values at each condition reflect the range of assumed activities of Fe and SiO2 (see text for details). The stars denote the case with both activities equal to one. See tabulated values in the accompanying spreadsheet for details of the calculations.

Extended Data Table 1 Hyperfine parameters of ferropericlase from KK203 determined from room temperature Mössbauer spectrum
Full size table

Supplementary information

Supplementary Table 1

Chemical analyses are provided in wt% oxides.

Supplementary Table 2

Standards, analyzing crystals and detection limits for EPMA analyses.

Supplementary Table 3

Calculations of fO2 for diamond KK203 using methodology modified as previously described34.

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Nestola, F., Regier, M.E., Luth, R.W. et al. Extreme redox variations in a superdeep diamond from a subducted slab. Nature 613, 85–89 (2023). https://doi.org/10.1038/s41586-022-05392-8

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