Accessible Requires Authentication Published by De Gruyter January 3, 2017

Bridgmanite-like crystal structure in the novel Ti-rich phase synthesized at transition zone condition

Luca Bindi, Ekaterina Sirotkina, Andrey V. Bobrov, Michael J. Walter, Dmitry Pushcharovsvsky and Tetsuo Irifune
From the journal American Mineralogist

Abstract

A new Ti-bearing bridgmanite-like phase with a threefold commensurate superstructure of the ideal MgSiO3-perovskite structure was observed in a [Mg5/6Al1/6][Si1/2Ti1/3Al1/6]O3 crystal synthesized in the model system Mg3Al2Si3O12–MgTiO3 at 20 GPa and 1600 °C. The compound was found to be orthorhombic, space group Pnma, with lattice parameters a = 14.767(3), b = 6.958(1), c = 4.812(1) Å, V = 494.4(2) Å3, which represents a 3a × b × c superstructure of the typical Pnma perovskite structure. The structure was refined to R = 0.024 using 846 independent reflections. The superstructure mainly arises from the ordering of titanium in one of the octahedral positions. Crystal-chemical details of the different polyhedra in the superstructure are discussed in comparison to pure MgSiO3. This is the first documented superstructure of a bridgmanite phase, and Ti-rich bridgmanite in the lower mantle arising from local Tienrichments may exhibit different physical properties and elemental partitioning behavior from Ti-poor, peridotitic bridgmanite. The study also shows that large amounts of Ti can stabilize bridgmanite-like compounds at considerably lower pressure than lower mantle conditions.

Acknowledgments

Thanks are due to Fabrizio Nestola, Ian Swainson, and three anonymous referees for their insightful comments. The research was supported by “progetto di Ateneo 2014, University of Firenze” to L.B., by CNR, Istituto di Geoscienze e Georisorse sezione di Firenze, Italy, and by the Russian Foundation for Basic Research (project nos. 16-05-00419 and 15-05-50033) to E.S. and A.B. E.S. thanks Geodynamics Research Center, Ehime University, Matsuyama, Japan, for support of her visit in 2016.

References cited

Albee, A.L., and Ray, L. (1970) Correction factors for electron probe analysis of silicate, oxides, carbonates, phosphates, and sulfates. Analytical Chemistry, 48, 1408–1414. Search in Google Scholar

Armstrong, L.S., Walter, M.J., Tuff, J.R., Lord, O.T., Lennie, A.R., Kleppe, A.K., and Clarke, S.M. (2012) Perovskite phase relations in the system CaO-MgO-TiO2-SiO2 and implications for deep mantle lithologies. Journal of Petrology, 53, 611–635. Search in Google Scholar

Audetat, A., and Keppler, H. (2005) Solubility of rutile in subduction zone fluids, as determined by experiments in the hydrothermal diamond anvil cell. Earth and Planetary Science Letters, 232, 393–402. Search in Google Scholar

Bence, A.E., and Albee, A.L. (1968) Empirical correction factors for the electron microanalysis of silicate and oxides. Journal of Geology, 76, 382–403. Search in Google Scholar

Bindi, L., Sirotkina, E.A., Bobrov, A.V., and Irifune, T. (2014) Chromium solubility in perovskite at high pressure: The structure of (Mg1−xCrx)(Si1−xCrx)O3 (with x = 0.07) synthesized at 23 GPa and 1600°C. American Mineralogist, 99, 866–869. Search in Google Scholar

Brenker, F.E., Vincze, L., Vekemans, B., Nasdala, L., Stachel, T., Vollmer, C., Kersten, M., Somogyif, A., Adams, F., Joswig, W., and Harris, J.W. (2005) Detection of a Ca-rich lithology in the Earth’s deep (300 km) convecting mantle. Earth and Planetary Science Letters, 236, 579–587. Search in Google Scholar

Brese, N.E., and O’Keeffe, M. (1991) Bond-valence parameters for solids. Acta Crystallographica, B47, 192–197. Search in Google Scholar

Dobson, D.P., and Jacobsen, S.D. (2004) The flux growth of magnesium silicate perovskite single crystals. American Mineralogist, 89, 807–811. Search in Google Scholar

Harte, B. (2010) Diamond formation in the deep mantle: the record of mineral inclusions and their distribution in relation to mantle dehydration zones. Mineralogical Magazine, 74, 189–215. Search in Google Scholar

Hill, R.J., Newton, M.D., and Gibbs, G.V. (1983) A crystal chemical study of stishovite. Journal of Solid State Chemistry, 47, 185–200. Search in Google Scholar

Ibers, J.A., and Hamilton, W.C., Eds. (1974) International Tables for X-ray Crystallography, vol. IV, 366 p. Kynock, Dordrecht, The Netherlands. Search in Google Scholar

Irifune, T., Kurio, A., Sakamoto, S., Inoue, T., Sumiya. H., and Funakoshi, K. (2004) Formation of pure polycrystalline diamond by direct conversion of graphite at high pressure and high temperature. Physics of the Earth and Planetary Interiors, 143-144, 593–600. Search in Google Scholar

Katsura, T., and Ito, E. (1989) The system Mg2SiO4-Fe2SiO4 at high pressure and temperatures: precise determination of stabilities of olivine, modified spinel, and spinel. Journal of Geophysical Research, 94, 15663–15670. Search in Google Scholar

Kojitani, H., Katsura, T., and Akaogi, M. (2007) Aluminum substitution mechanisms in perovskite-type MgSiO3: an investigation by Rietveld analysis. Physics and Chemistry of Minerals, 34, 257–267. Search in Google Scholar

Kubo, A., and Akaogi, M. (2000) Post-garnet transitions in the system Mg4Si4O12 −Mg3Al2Si3O12 up to 28 GPa: phase relations of garnet, ilmenite and perovskite. Physics of the Earth and Planetary Interiors, 121, 85–102. Search in Google Scholar

Kubo, A. Suzuki, T., and Akaogi, M. (1997) High pressure phase equilibria in the system CaTiO3-CaSiO3: stability of perovskite solid solutions. Physics and Chemistry of Minerals, 24, 488–494. Search in Google Scholar

Liebske, C., Corgne, A., Frost, D.J., Rubie, D.C., and Wood, B.J. (2005) Compositional effects on element partitioning between Mg-silicate perovskite and silicate melts. Contributions to Mineralogy and Petrology, 149, 113–128. Search in Google Scholar

McDonough, W.F., and Sun, S.-S. (1995) The compositoon of the Earth. Chemical Geology, 120, 223–253. Search in Google Scholar

O’Keeffe, M., Hyde, B.G., and Bovin, J.O. (1979) Contribution to the crystal chemistry of orthorhombic perovskite: MgSiO3 and NaMgF3. Physics and Chemistry of Minerals, 4, 299–305. Search in Google Scholar

Oxford Diffraction (2006) CrysAlis RED (ver. 1.171.31.2) and ABSPACK in CrysAlis RED. Oxford Diffraction, Abingdon, Oxfordshire, England. Search in Google Scholar

Robinson, K., Gibbs, G.V., and Ribbe, P.H. (1971) Quadratic elongation: a quantitative measure of distortion in coordination polyhedra. Science, 172, 567–570. Search in Google Scholar

Sheldrick, G.M. (2008) A short history of SHELX. Acta Crystallographica, A64, 112–122. Search in Google Scholar

Sinmyo, R., Bykova, E., McCammon, C., Kupenko, I., Potapkin, V., and Dubrovinsky, L. (2014) Crystal chemistry of Fe3+-bearing (Mg,Fe)SiO3 perovskite: a singlecrystal X-ray diffraction study. Physics and Chemistry of Minerals, 41, 409–417. Search in Google Scholar

Sirotkina, E.A., Bobrov, A.V., Bindi, L., and Irifune, T. (2015) Phase relations and formation of chromium-rich phases in the system Mg4Si4O12–Mg3Cr2Si3O12 at 10–24 GPa and 1,600 °C. Contributions to Mineralogy and Petrology, 169, 2, 10.1007/s00410-014-1097-0. Search in Google Scholar

Swope, R.J., Smyth, J.R., and Larson, A.C. (1995) H in rutile-type compounds: I. Single-crystal neutron and X-ray diffraction study of H in rutile. American Mineralogist, 80, 448–453. Search in Google Scholar

Thomas, N.W. (1996) The compositional dependence of octahedral tilting in orthorhombic and tetragonal perovskites. Acta Crystallographica, B52, 16–31. Search in Google Scholar

Thomson, A.R., Kohn, S.C., Bulanova, G.P., Smith, C.B., Araujo, D., EIMF, and Walter, M.J. (2014) Origin of sub-lithospheric diamonds from the Juina-5 kimberlite (Brazil): constraints from carbon isotopes and inclusion compositions. Contributions to Mineralogy and Petrology, 168, 1081. Search in Google Scholar

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

Tropper, P., and Manning, C.E. (2005) Very low solubility of rutile in H2O at high pressure and temperature, and its implications for Ti mobility in subduction zones. American Mineralogist, 90, 502–505. Search in Google Scholar

Tschauner, O., Ma, C., Beckett, J.R., Prescher, C., Prakapenka, V., and Rossman, G.R. (2014) Discovery of bridgmanite, the most abundant mineral in Earth, in a shocked meteorite. Science, 346, 1100–1102. Search in Google Scholar

Walter, M.J., Kubo, A., Yoshino, T., Brodholt, J., Koga, K.T., and Ohishi, Y. (2004) Phase relations and equation-of-state of aluminous Mg-Silicate perovskite and implications for Earth’s lower mantle. Earth and Planetary Science Letters, 222, 501–516. Search in Google Scholar

Walter, M.J., Bulanova, G.P., Armstrong, L.S., Keshav, S., Blundy, J.D., Gudfinnsson, G., Lord, O.T., Lennie, A.R., Clark, S.M., Smith, C.B., and Gobbo, L. (2008) Primary carbonatite melt from deeply subducted oceanic crust. Nature, 454, 622–625. Search in Google Scholar

Walter, M.J., Kohn, S.C., Araujo, D., Bulanova, G.P., Smith, C.B., Gaillou, E., Wang, J., Steele, A., and Shirey, S.B. (2011) Deep mantle cycling of oceanic crust: evidence from diamonds and their mineral inclusions. Science, 334, 54–57. Search in Google Scholar

Wilson, M. (1989) Igneous Petrogenesis—A global tectonic approach, 466 p. Kluwer, Dordrecht. Search in Google Scholar

Yamada, A., Inoue, T., and Irifune, T. (2004) Melting of enstatite from 13 to 18 GPa under hydrous conditions. Physics of the Earth and Planetary Interiors, 147, 45–56. Search in Google Scholar

Yamanaka, T., Hirai, M., and Komatsu, Y. (2002) Structure change of Ca1−xSrx TiO3 perovskite with composition and pressure. American Mineralogist, 87, 1183–1189. Search in Google Scholar

Zedgenizov, D.A., Shatsky, V.S., Panin, A.V., Evtushenko, O.V., Ragozin, A.L., and Kagi, H. (2015) Evidence for phase transitions in mineral inclusions in superdeep diamonds of the São Luiz deposit (Brazil). Russian Geology and Geophysics, 56, 296–305. Search in Google Scholar

Received: 2016-8-19
Accepted: 2016-11-13
Published Online: 2017-1-3
Published in Print: 2017-1-1

© 2017 by Walter de Gruyter Berlin/Boston