Reaction between Forsterite and Nitrogen Fluid at High Pressure and High Temperature


Behavior of nitrogen in the deep Earth still remains unrevealed. Geochemical data suggest that substantial amount of nitrogen could be stored in the deep Earth. In this study, reactions between forsterite (Mg2SiO4) and molecular nitrogen (N2) were investigated at high pressure and high temperature using laser-heating diamond anvil cells (DACs). Pressure in the DAC was estimated from Raman spectra of nitrogen before heating and the initial pressure was set at 5 GPa. Pelleted sample of powder forsterite or a single crystal of forsterite was loaded in the DAC with N2 fluid. A carbon dioxide laser (λ = 10.64 μm, <100 W) and a fiber laser (λ = 1.019 μm, <100 W) were used to heat forsterite in the temperature range from 1300 to 3500 K. An SEM image on the surface of the recovered forsterite crystal after the laser heating showed a stepwise texture which strongly suggests the dissolution of forsterite into the N2 fluid. The EDS chemical mapping showed that Mg-rich area and Si-poor area overlapping each other, which suggests the preferential dissolution of MgO component and its precipitation from the N2 fluid. X-ray diffraction patterns of the powder and single crystal forsterite samples after the reaction showed reflections assignable to orthopyroxene (MgSiO3) and periclase (MgO). The present experimental results indicate that Mg2SiO4 incongruently melts into MgSiO3 and MgO in N2 fluid. Moreover, N1s XPS spectra collected from a single crystal of forsterite after the reaction with N2 fluid revealed three components assignable to \({\text{NH}}_{4}^{ + },\) N2, and N3–. The present study provides a new clue to the reaction between forsterite and molecular nitrogen under the upper mantle condition.

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  1. 1

    T. Andersen, E. A. Burke, and E. R. Neumann, “Nitrogen-rich fluid in the upper mantle: fluid inclusions in spinel dunite from Lanzarote, Canary Islands,” Contrib. Mineral. Petrol. 120, 20–28 (1995).

    Article  Google Scholar 

  2. 2

    J. C. Barry, “Voidites in diamond: do they contain nitrogen?” Ultramicroscopy 20, 169–176 (1986).

    Article  Google Scholar 

  3. 3

    D. Briggs and M. P. Seah, Practical Surface Analysis. Auger and X-ray Photoelectron Spectroscopy, 2nd ed., (John Wiley, 1990).

    Google Scholar 

  4. 4

    S. Buchsbaum, R. L. Mills, and D. Schiferl, “Phase diagram of N2 determined by Raman spectroscopy from 15 to 300 K at pressures to 52 GPa,” J. Phys. Chem, 88, 2522–2525 (1984).

    Article  Google Scholar 

  5. 5

    L. F. Dobrzhinetskaya, R. Wirth, J. Yang, H. W. Green, I. D. Hutcheon, P. K. Weber, and E. Grew S., “Qingsongite, natural cubic boron nitride: the first boron mineral from the Earth’s mantle,” Am. Mineral. 99, 764–772 (2014).

    Article  Google Scholar 

  6. 6

    P. B. Hirsh, J. L. Hutchison, and J. Titchmarsh, “Voidites in diamond: evidence for a crystalline phase containing nitrogen,” Philos. Mag. A., 54, L49–L54 (1986).

    Article  Google Scholar 

  7. 7

    T. Inoue, “Effect of water on melting phase relations and melt composition in the system Mg2SiO4–MgSiO3–H2O up to 15 GPa,” Phys. Earth Planet. Inter. 85, 237–263 (1994).

    Article  Google Scholar 

  8. 8

    F. Kaminsky, and R. Wirth, “Nitrides and carbonitrides from the lowermost mantle and their importance in the search for Earth’s “lost” nitrogen,” Am. Mineral. 102, 1667–1676 (2017).

    Article  Google Scholar 

  9. 9

    Y. Li, and H. Keppler H, “Nitrogen speciation in mantle and crustal fluids,” Geochim. Cosmochim. Acta 129, 13–32 (2014).

    Article  Google Scholar 

  10. 10

    Y. Li, M. Wiedenbeck, S. Shcheka, and H. Keppler, “Nitrogen solubility in upper mantle minerals,” Earth Planet. Sci. Lett. 377–378, 311–323 (2013).

    Article  Google Scholar 

  11. 11

    K. D. Litasov, A. Shatskiy, D. W. Ponomarev, and P. N. Gavryushkin, “Equations of state of Iron nitrides–Fe3Nx andγ–Fe4Ny to 30 GPa and 1200 K and implication for nitrogen in the Earth’s core,” J. Geophys. Res.: Solid Earth 122, 3574–3584 (2017).

    Article  Google Scholar 

  12. 12

    W. Liu, and P. X. Fei, “Methane–rich fluid inclusions from ophiolitic dunite and post–collisional mafic–ultramafic intrusion: the mantle dynamics underneath the Palaeo–Asian Ocean through to the post–collisional period,” Earth Planet. Sci. Lett. 242, 286–301 (2006).

    Article  Google Scholar 

  13. 13

    B. Marty, “The origins and concentrations of water, carbon, nitrogen and noble gases on Earth,” Earth Planet. Sci. Lett. 313–314, 56–66 (2012).

    Article  Google Scholar 

  14. 14

    W. F. McDonough, and S. S. Sun, “The composition of the Earth,” Chem. Geol. 120, 223–253 (1995).

    Article  Google Scholar 

  15. 15

    R. L. Mills, B. Olinger, and D. T. Cromer, “Structures and phase diagrams of N2 and CO to 13 GPa by X-ray diffraction,” J. Chem. Phys. 84, 2837–2845 (1986).

    Article  Google Scholar 

  16. 16

    S. Minobe, Y. Nakajima, K. Hirose, and Y. Ohishi, “Stability and compressibility of a new iron–nitride β–Fe7N3 to core pressures,” Geophys. Res. Lett. 42, 5206–5211 (2015).

    Article  Google Scholar 

  17. 17

    O. Navon, R. Wirth, C. Schmidt, B. M. Jablon, A. Schreiber, and S. Emmanuel, “Solid molecular nitrogen (δ–N2) in Juina diamonds: exsolution at the base of the transition zone,” Earth Planet. Sci. Lett. 464, 237–247 (2017).

    Article  Google Scholar 

  18. 18

    M. Roskosz, B. O. Mysen, and G. D. Cody, “Dual speciation of nitrogen in silicate melts at high pressure and temperature: An experimental study,” Geochem Cosmochim. Acta 70, 2902–2918 (2006).

    Google Scholar 

  19. 19

    Y. Seto, “Whole pattern fitting for two–dimensional diffraction patterns from polycrystalline materials,” The Review of High Pressure Science and Technology 22, 144–152 (in Japanese with English abstract) (2012).

  20. 20

    A. Shinozaki, H. Hirai, H. Ohfuji, T. Okada, S. Machida, and T. Yagi, “Influence of H2 fluid on the stability and dissolution of Mg2SiO4 forsterite under high pressure and high temperature,” Am. Mineral. 98, 1604–1609 (2013).

    Article  Google Scholar 

  21. 21

    A. Watenphul, B. Wunder, and W. Heinrich, “High-pressure ammonium-bearing silicates: Implications for nitrogen and hydrogen storage in the Earth’s mantle,” Am. Mineral. 94, 283–292 (2009).

    Article  Google Scholar 

  22. 22

    A. Watenphul, B. Wunder, R. Wirth, and W. Heinrich, “Ammonium-bearing clinopyroxene: a potential nitrogen reservoir in the Earth’s mantle,” Chem. Geol. 270, 240–248 (2010).

    Article  Google Scholar 

  23. 23

    T. Yagi and J. Susaki, “A laser heating system for diamond anvil using CO2 laser” in “High–Pressure Research: Application to Earth and Planetary Sciences”, Ed. by Y. Syono and M. H. Manghnani, (TERRAPUB, AGU, Tokyo/, Washington, 1992), pp. 51–54

  24. 24

    T. Yoshioka, M. Wiedenbeck, S. Scheka, and H. Keppler, “Nitrogen solubility in the deep mantle and the origin of Earth’s primordial nitrogen budget,” Earth Planet. Sci. Lett. 488, 134–143 (2018).

    Article  Google Scholar 

  25. 25

    D. A. Zedgenizov, and K. D. Litasov, “Looking for “missing” nitrogen in the deep Earth,” Am. Mineral. 102, 1769–1770 (2017).

    Article  Google Scholar 

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We are sincerely grateful to Drs. Konstantin Litasov and Andrei Shiryaev for their review comments which greatly improved the manuscript.


This research was supported by JSPS-RDBR bilateral program and JSPS KAKENHI Grant Numbers 15K13600, 15H05828. Synchrotron X-ray diffraction measurements were performed under the approval of the Photon Factory Program Advisory Committee (Proposal numbers 2015G694 and 2017G644). SEM analyses were performed under the collaborative research project of PRIUS, Geodynamic Research Center, Ehime University. XPS measurements were conducted at Advanced Characterization Nanotechnology Platform of the University of Tokyo, supported by “Nanotechnology Platform” of the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan.

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Correspondence to Hiroyuki Kagi.

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Kagi, H., Kubo, T., Shinozaki, A. et al. Reaction between Forsterite and Nitrogen Fluid at High Pressure and High Temperature. Geochem. Int. 57, 956–963 (2019).

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  • nitrogen
  • forsterite
  • incongruent melting
  • diamond anvil cell (DAC)