Laboratory experiments and seismology data have created a clear theoretical picture of the most abundant minerals that comprise the deeper parts of the Earth’s mantle. Discoveries of some of these minerals in ‘super-deep’ diamonds—formed between two hundred and about one thousand kilometres into the lower mantle—have confirmed part of this picture1,2,3,4,5. A notable exception is the high-pressure perovskite-structured polymorph of calcium silicate (CaSiO3). This mineral—expected to be the fourth most abundant in the Earth—has not previously been found in nature. Being the dominant host for calcium and, owing to its accommodating crystal structure, the major sink for heat-producing elements (potassium, uranium and thorium) in the transition zone and lower mantle, it is critical to establish its presence. Here we report the discovery of the perovskite-structured polymorph of CaSiO3 in a diamond from South African Cullinan kimberlite. The mineral is intergrown with about six per cent calcium titanate (CaTiO3). The titanium-rich composition of this inclusion indicates a bulk composition consistent with derivation from basaltic oceanic crust subducted to pressures equivalent to those present at the depths of the uppermost lower mantle. The relatively ‘heavy’ carbon isotopic composition of the surrounding diamond, together with the pristine high-pressure CaSiO3 structure, provides evidence for the recycling of oceanic crust and surficial carbon to lower-mantle depths.
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Joswig, W., Stachel, T., Harris, J. W., Baur, W. & Brey, G. P. New Ca-silicate inclusions in diamonds – tracers from the lower mantle. Earth Planet. Sci. Lett. 173, 1–6 (1999)
Harte, B. in Mantle Petrology: Field Observations and High-Pressure Experimentation Vol. 6 (eds Fei, Y. et al.) 125–153 (Geochemical Society, 1999)
Stachel, T., Harris, J. W., Brey, G. P. & Joswig, W. Kankan diamonds (Guinea) II: lower mantle inclusion paragenesis. Contrib. Mineral. Petrol. 140, 16–27 (2000)
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)
Pearson, D. G. et al. Hydrous mantle transition zone indicated by ringwoodite included within diamond. Nature 507, 221–224 (2014)
Smith, E. M. et al. Large gem diamonds from metallic liquid in Earth’s deep mantle. Science 354, 1403–1405 (2016)
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)
Thomson, A., Walter, M. J., Kohn, S. C. & Brooker, R. A. Slab melting as a barrier to deep carbon subduction. Nature 529, 76–79 (2016)
Harte, B. & Hudson, N. F. C. Mineral associations in diamonds from the lowermost upper 254 mantle and uppermost lower mantle. In Proc. of the 10th International Kimberlite Conference Vol. 1 (eds Pearson, D. G. et al.) 235–253 (Springer, 2013)
Stixrude, L. & Lithgow-Bertelloni, C. Geophysics of chemical heterogeneity in the mantle. Annu. Rev. Earth Planet. Sci. 40, 569–595 (2012)
Ringwood, A. E. Composition and Petrology of the Earth’s Mantle (McGraw-Hill, 1975)
Corgne, A. & Wood, B. J. Trace element partitioning and substitution mechanisms in calcium perovskites. Contrib. Mineral. Petrol. 149, 85–97 (2005)
Anzolini, C. et al. Depth of formation of CaSiO3-walstromite included in super-deep diamonds. Lithos 265, 138–147 (2016)
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. Russ. Geol. Geophys. 56, 211–220 (2015)
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)
Nowell, G. M. et al. Hf isotope systematics of kimberlites and their megacrysts: new constraints on their source region. J. Petrol. 45, 1583–1612 (2004)
Moore, A. D. The origin of large irregular gem-quality type II diamonds and the rarity of blue type IIb varieties. S. Afr. J. Geol. 117, 219–236 (2014)
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)
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)
Walter, M. J. et al. Deep mantle cycling of oceanic crust: evidence from diamonds and their mineral inclusions. Science 334, 54–57 (2011)
Kubo, A., Suzuki, T. & Akaogi, M. High pressure phase equilibria in the system CaTiO3-CaSiO3: stability of perovskite solid solutions. Phys. Chem. Miner. 24, 488–494 (1997)
Mazzucchelli, M. L. et al. Elastic geothermobarometry: corrections for the geometry of the host-inclusion system. Geology https://doi.org/10.1130/G39807.1 (2018)
Lafuente, B., Downs, R.T., Yang, H. & Stone, N. in Highlights in Mineralogical Crystallography (eds Armbruster, T. & Danisi, R. M. ) 1–30 (De Gruyter, 2016)
Gasparik, T., Wolf, L. & Smith, C. M. Experimental determination of phase relations in the CaSiO3 system from 8 to 15 GPa. Am. Mineral. 79, 1219–1222 (1994)
Ringwood, A. E. & Major, A. Synthesis of majorite and other high pressure garnets and perovskites. Earth Planet. Sci. Lett. 12, 411–418 (1971)
Hirose, K. & Fei, Y. Subsolidus and melting phase relations of basaltic composition in the uppermost lower mantle. Geochim. Cosmochim. Acta 66, 2099–2108 (2002)
Cartigny, P., Palot, M., Thomassot, E. & Harris, J. W. Diamond formation: a stable isotope perspective. Annu. Rev. Earth Planet. Sci. 42, 699–732 (2014)
Burnham, A. D. et al. Stable isotope evidence for crustal recycling as recorded by superdeep diamonds. Earth Planet. Sci. Lett. 432, 374–380 (2015)
McMillan, P. & Ross, N. The Raman spectra of several orthorhombic calcium oxide perovskites. Phys. Chem. Miner. 16, 21–28 (1988)
Yin, C. D., Okuno, M., Morikawa, H., Marumo, F. & Yamanaka, T. Structural analysis of CaSiO3 glass by X-Ray diffraction and Raman spectroscopy. J. Non-Cryst. Solids 80, 167–174 (1986)
Zerr, A., Serghiou, G. & Boehler, R. Melting of CaSiO3 perovskite to 430 kbar and first in-situ measurements of lower mantle eutectic temperatures. Geophys. Res. Lett. 24, 909–912 (1997)
Mendelssohn, M. J. & Milledge, H. J. Geologically significant information from routine analysis of the mid-infrared spectra of diamonds. Int. Geol. Rev. 37, 95–110 (1995)
Pouchou, J. L. & Pichoir, F. in Microbeam Analysis (ed. Armstrong, J. T. ) 104–106 (San Francisco Press, 1985)
Buttner, R. H. & Maslen, E. N. Electron difference density and structural parameters in CaTiO3 . Acta Crystallogr. C 48, 644–649 (1992)
Stachel, T., Harris, J. W. & Muehlenbachs, K. Sources of carbon in inclusion bearing diamonds. Lithos 112, 625–637 (2009)
Huber, P. Robust Statistics 107–108 (Wiley, 1981)
We thank M. Regier for proofreading the paper. F.N. is supported by the European Research Council (ERC) Starting Grant number 307322. M.K.’s work and sample collection was possible thanks to an NSERC Discovery grant. N.K. acknowledges funding from the Dr. Eduard Gübelin Association through a 2015 research scholarship. D.G.P. was funded by an NSERC CERC award. M.A. was supported by the ERC under the European Union’s Horizon 2020 research and innovation programme (grant 714936) ‘TRUE DEPTHS’ and by the SIR-MIUR grant (RBSI140351) ‘MILE DEEp’. We thank L. Litti and M. Meneghetti of the Laboratory of Nanostructures and Optics of the Department of Chemical Sciences, University of Padova for their help in acquiring and interpreting the Raman data. F.N. and D.G.P. were supported by the Deep Carbon Observatory. M.G.P. was supported by NERC grant NE/M015181/1.
The authors declare no competing financial interests.
Reviewer Information Nature thanks B. Harte and the other anonymous reviewer(s) for their contribution to the peer review of this work.
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Extended data figures and tables
Extended Data Figure 1 Baseline-corrected FTIR absorption spectrum of the diamond containing the Ca-Pv inclusion.
The inset shows the absorption peaks of two types of diamond defect: A-aggregate N, in which a pair of nitrogen atoms substitute carbon atoms (the ‘A-centre’), and B-aggregate N, in which four nitrogen atoms replace carbon atoms around a carbon vacancy (the ‘B-centre’). The values in parentheses give the theoretical peak positions (in cm−1).
Extended Data Figure 2 Comparison between the Raman spectrum of CaTiO3 measured in this work (blue) and that reported in the RRUFF database (red).
The spectrum reported in the RRUFF database (card number R050456) is from ref. 23.
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Nestola, F., Korolev, N., Kopylova, M. et al. CaSiO3 perovskite in diamond indicates the recycling of oceanic crust into the lower mantle. Nature 555, 237–241 (2018). https://doi.org/10.1038/nature25972
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