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Dry metastable olivine and slab deformation in a wet subducting slab

Abstract

A widely accepted explanation for deep-focus earthquakes is that they are caused by the delayed transformation kinetics of dry olivine, which would seem to require dry subducting slabs. However, many geochemical and geophysical observations and mineral physics data indicate that water is present within both hydrous and nominally anhydrous minerals, implying hydrated subducting slabs. The presence of metastable olivine in wet slabs is therefore paradoxical, and the hydration state of the slabs remains an open question. Here, we report results of water-partitioning experiments between olivine, wadsleyite and a major dense hydrous magnesium silicate in slabs, hydrous phase A, under water-undersaturated conditions. We show that olivine and wadsleyite coexisting with hydrous phase A are kinetically dry and contain less than 1 ppm and approximately 300 ppm water, respectively. Our results suggest that olivine and wadsleyite show dry transformation kinetics even in wet slabs. It is therefore possible that olivine transformation as a cause of deep-focus earthquakes and large slab deformation creating stagnant slabs could occur in the water-undersaturated wet slabs. These processes could be caused jointly by dehydration of hydrous minerals and the subsequent rapid phase transformation when the dehydration starts at lower temperatures than the phase transformation.

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Fig. 1: Representative photographs of cross sections of recovered samples.
Fig. 2: Representative unpolarized FTIR spectra of forsterite and wadsleyite single crystals coexisting with hydrous phase A.
Fig. 3: The water content in forsterite at 8–12 GPa and wadsleyite at 12–20 GPa with increasing temperature.
Fig. 4: Slab deformation and formation of a stagnant slab in a wet descending slab and their possible linkage with dehydration of hydrous phases.

Data availability

All data used in this paper are available on Zenodo (https://doi.org/10.5281/zenodo.3936232). Any other data can be requested by emailing the corresponding author.

References

  1. 1.

    Mei, S. & Kohlstedt, D. L. Influence of water on plastic deformation of olivine aggregates: 2. Dislocation creep regime. J. Geophys. Res. Solid Earth 105, 21471–21481 (2000).

    Google Scholar 

  2. 2.

    Karato, S. I. & Jung, H. Effects of pressure on high-temperature dislocation creep in olivine. Philos. Mag. A 83, 401–414 (2003).

    Google Scholar 

  3. 3.

    Kubo, T., Ohtani, E., Kato, T., Shinmei, T. & Fujino, K. Effects of water on the α–β transformation kinetics in San Carlos olivine. Science 281, 85–87 (1998).

    Google Scholar 

  4. 4.

    Sung, C. M. & Burns, R. G. Kinetics of the olivine→spinel transition: implications to deep-focus earthquake genesis. Earth Planet. Sci. Lett. 32, 165–170 (1976).

    Google Scholar 

  5. 5.

    Perrillat, J. P. et al. Kinetics of the olivine–ringwoodite transformation and seismic attenuation in the Earth’s mantle transition zone. Earth Planet. Sci. Lett. 433, 360–369 (2016).

    Google Scholar 

  6. 6.

    Iidaka, T. & Suetsugu, D. Seismological evidence for metastable olivine inside a subducting slab. Nature 356, 593–595 (1992).

    Google Scholar 

  7. 7.

    Jiang, G., Zhao, D. & Zhang, G. Seismic evidence for a metastable olivine wedge in the subducting Pacific slab under Japan Sea. Earth Planet. Sci. Lett. 270, 300–307 (2008).

    Google Scholar 

  8. 8.

    Kirby, S. Mantle phase changes and deep-earthquake faulting in subducting lithosphere. Science 252, 216–224 (1991).

    Google Scholar 

  9. 9.

    Green, H. W. II & Houston, H. The mechanisms of deep earthquakes. Annu. Rev. Earth Planet. Sci. 23, 169–213 (1995).

    Google Scholar 

  10. 10.

    Schubnel, A. et al. Deep-focus earthquake analogs recorded at high pressure and temperature in the laboratory. Science 341, 1377–1380 (2013).

    Google Scholar 

  11. 11.

    Kawakatsu, H. & Yoshioka, S. Metastable olivine wedge and deep dry cold slab beneath southwest Japan. Earth Planet. Sci. Lett. 303, 1–10 (2011).

    Google Scholar 

  12. 12.

    Green, H. W. II, Chen, W. P. & Brudzinski, M. R. Seismic evidence of negligible water carried below 400-km depth in subducting lithosphere. Nature 467, 828–831 (2010).

    Google Scholar 

  13. 13.

    Hosoya, T., Kubo, T., Ohtani, E., Sano, A. & Funakoshi, K. I. Water controls the fields of metastable olivine in cold subducting slabs. Geophys. Res. Lett. 32, L17305 (2005).

    Google Scholar 

  14. 14.

    Du Frane, W. L., Sharp, T. G., Mosenfelder, J. L. & Leinenweber, K. Ringwoodite growth rates from olivine with ~75 ppmw H2O: metastable olivine must be nearly anhydrous to exist in the mantle transition zone. Phys. Earth Planet. Inter. 219, 1–10 (2013).

    Google Scholar 

  15. 15.

    Peslier, A. H., Schönbächler, M., Busemann, H. & Karato, S. I. Water in the Earth’s interior: distribution and origin. Space Sci. Rev. 212, 743–810 (2017).

    Google Scholar 

  16. 16.

    Hacker, B. R., Peacock, S. M., Abers, G. A. & Holloway, S. D. Subduction factory 2. Are intermediate‐depth earthquakes in subducting slabs linked to metamorphic dehydration reactions? J. Geophys. Res. Solid Earth 108, 2030 (2003).

    Google Scholar 

  17. 17.

    Schmidt, M. W. & Poli, S. Experimentally based water budgets for dehydrating slabs and consequences for arc magma generation. Earth Planet. Sci. Lett. 163, 361–379 (1998).

    Google Scholar 

  18. 18.

    Yamasaki, T. & Seno, T. Double seismic zone and dehydration embrittlement of the subducting slab. J. Geophys. Res. 108, 2212 (2003).

    Google Scholar 

  19. 19.

    van Keken, P. E., Hacker, B. R., Syracuse, E. M. & Abers, G. A. Subduction factory: 4. Depth-dependent flux of H2O from subducting slabs worldwide. J. Geophys. Res. 116, 1401 (2011).

    Google Scholar 

  20. 20.

    Peacock, S. M. Are the lower planes of double seismic zones caused by serpentine dehydration in subducting oceanic mantle? Geology 29, 299–302 (2001).

    Google Scholar 

  21. 21.

    Seno, T. & Yamanaka, Y. in Subduction: Top to Bottom (eds Bebout, G. E. et al.) 347–355 (AGU, 1996).

  22. 22.

    Hirano, N. et al. Volcanism in response to plate flexure. Science 313, 1426–1428 (2006).

    Google Scholar 

  23. 23.

    Cai, C., Wiens, D. A., Shen, W. & Eimer, M. Water input into the Mariana subduction zone estimated from ocean-bottom seismic data. Nature 563, 389–392 (2018).

    Google Scholar 

  24. 24.

    Ranero, C. R., Morgan, J. P., McIntosh, K. & Reichert, C. Bending-related faulting and mantle serpentinization at the Middle America trench. Nature 425, 367–373 (2003).

    Google Scholar 

  25. 25.

    Komabayashi, T., Omori, S. & Maruyama, S. Petrogenetic grid in the system MgO–SiO2–H2O up to 30 GPa, 1600 °C: applications to hydrous peridotite subducting into the Earth’s deep interior. J. Geophys. Res. 109, B03206 (2004).

    Google Scholar 

  26. 26.

    Kirby, S. H., Okal, E. A., Stein, S. & Rubie, D. C. Metastable mantle phase transformations and deep earthquake in subducting oceanic lithosphere. Rev. Geophys. 34, 261–306 (1996).

    Google Scholar 

  27. 27.

    Bolfan-Casanova, N. Water in the Earth’s mantle. Mineral. Mag. 69, 229–257 (2005).

    Google Scholar 

  28. 28.

    Smyth, J. R., Frost, D. J., Nestola, F., Holl, C. M. & Bromiley, G. Olivine hydration in the deep upper mantle: effects of temperature and silica activity. Geophys. Res. Lett. 33, L15301 (2006).

    Google Scholar 

  29. 29.

    Litasov, K. D., Shatskiy, A., Ohtani, E. & Katsura, T. Systematic study of hydrogen incorporation into Fe-free wadsleyite. Phys. Chem. Miner. 38, 75–84 (2011).

    Google Scholar 

  30. 30.

    Hae, R., Ohtani, E., Kubo, T., Koyama, T. & Utada, H. Hydrogen diffusivity in wadsleyite and water distribution in the mantle transition zone. Earth Planet. Sci. Lett. 243, 141–148 (2006).

    Google Scholar 

  31. 31.

    Demouchy, S. & Mackwell, S. Water diffusion in synthetic iron-free forsterite. Phys. Chem. Miner. 30, 486–494 (2003).

    Google Scholar 

  32. 32.

    Demouchy, S. & Mackwell, S. Mechanisms of hydrogen incorporation and diffusion in iron-bearing olivine. Phys. Chem. Miner. 33, 347–355 (2006).

    Google Scholar 

  33. 33.

    Kudo, T., Ohtani, E., Hae, R. & Shimojuku, A. Diffusion of hydrogen in ringwoodite. AIP Conf. Proc. 833, 148–149 (2006).

    Google Scholar 

  34. 34.

    Keppler, H. & Bolfan-Casanova, N. Thermodynamics of water solubility and partitioning. Rev. Mineral. Geochem. 62, 193–230 (2006).

    Google Scholar 

  35. 35.

    Kubo, T., Ohtani, E. & Funakoshi, K. I. Nucleation and growth kinetics of the α–β transformation in Mg2SiO4 determined by in situ synchrotron powder X-ray diffraction. Am. Mineral. 89, 285–293 (2004).

    Google Scholar 

  36. 36.

    Ferrand, T. P. et al. Dehydration-driven stress transfer triggers intermediate-depth earthquakes. Nat. Commun. 8, 15247 (2017).

    Google Scholar 

  37. 37.

    Quinteros, J. & Sobolev, S. V. Constraining kinetics of metastable olivine in the Marianas slab from seismic observations and dynamic models. Tectonophysics 526, 48–55 (2012).

    Google Scholar 

  38. 38.

    Yoshioka, S., Torii, Y. & Riedel, M. R. Impact of phase change kinetics on the Mariana slab within the framework of 2-D mantle convection. Phys. Earth Planet. Inter. 240, 70–81 (2015).

    Google Scholar 

  39. 39.

    Zahradnik, J. et al. A recent deep earthquake doublet in light of long-term evolution of Nazca subduction. Sci. Rep. 7, 45153 (2017).

    Google Scholar 

  40. 40.

    Karato, S. I., Riedel, M. R. & Yuen, D. A. Rheological structure and deformation of subducted slabs in the mantle transition zone: implications for mantle circulation and deep earthquakes. Phys. Earth Planet. Inter. 127, 83–108 (2001).

    Google Scholar 

  41. 41.

    Mohiuddin, A., Karato, S. I. & Girard, J. Slab weakening during the olivine to ringwoodite transition in the mantle. Nat. Geosci. 13, 170–174 (2020).

    Google Scholar 

  42. 42.

    Čı́žková, H., van Hunen, J., van den Berg, A. P. & Vlaar, N. J. The influence of rheological weakening and yield stress on the interaction of slabs with the 670 km discontinuity. Earth Planet. Sci. Lett. 199, 447–457 (2002).

    Google Scholar 

  43. 43.

    Rosa, A. D. et al. Evolution of grain sizes and orientations during phase transitions in hydrous Mg2SiO4. J. Geophys. Res. 121, 7161–7176 (2016).

    Google Scholar 

  44. 44.

    Fukao, Y., Obayashi, M. & Nakakuki, T. & Deep Slab Project Group. Stagnant slab: a review. Annu. Rev. Earth Planet. Sci. 37, 19–46 (2009).

    Google Scholar 

  45. 45.

    Tielke, J. A., Zimmerman, M. E. & Kohlstedt, D. L. Hydrolytic weakening in olivine single crystals. J. Geophys. Res. 122, 3465–3479 (2017).

    Google Scholar 

  46. 46.

    Richard, G., Monnereau, M. & Rabinowicz, M. Slab dehydration and fluid migration at the base of the upper mantle: implications for deep earthquake mechanisms. Geophys. J. Int. 168, 1291–1304 (2017).

    Google Scholar 

  47. 47.

    Kagi, H., Parise, J. B., Cho, H., Rossman, G. R. & Loveday, J. S. Hydrogen bonding interactions in phase A [Mg7Si2O8(OH)6] at ambient and high pressure. Phys. Chem. Miner. 27, 225–233 (2000).

    Google Scholar 

  48. 48.

    Purevjav, N., Okuchi, T., Tomioka, N., Wang, X. & Hoffmann, C. Quantitative analysis of hydrogen sites and occupancy in deep mantle hydrous wadsleyite using single crystal neutron diffraction. Sci. Rep. 6, 34988 (2016).

    Google Scholar 

  49. 49.

    Purevjav, N., Okuchi, T. & Hoffmann, C. Strong hydrogen bonding in a dense hydrous magnesium silicate discovered by neutron Laue diffraction. IUCrJ 7, 370–374 (2020).

    Google Scholar 

  50. 50.

    Pacalo, R. E. & Parise, J. B. Crystal structure of superhydrous B, a hydrous magnesium silicate synthesized at 1400 °C and 20 GPa. Am. Mineral. 77, 681–684 (1992).

    Google Scholar 

  51. 51.

    Beran, A. & Putnis, A. A model of the OH positions in olivine, derived from infrared-spectroscopic investigations. Phys. Chem. Miner. 9, 57–60 (1983).

    Google Scholar 

  52. 52.

    Brodholt, J. P. & Refson, K. An ab initio study of hydrogen in forsterite and a possible mechanism for hydrolytic weakening. J. Geophys. Res. Solid Earth 105, 18977–18982 (2000).

    Google Scholar 

  53. 53.

    Ingrin, J. & Blanchard, M. Diffusion of hydrogen in minerals. Rev. Mineral. Geochem. 62, 291–320 (2006).

    Google Scholar 

  54. 54.

    Withers, A. C., Bureau, H., Raepsaet, C. & Hirschmann, M. M. Calibration of infrared spectroscopy by elastic recoil detection analysis of H in synthetic olivine. Chem. Geol. 334, 92–98 (2012).

    Google Scholar 

  55. 55.

    Bolfan-Casanova, N. et al. Examination of water quantification and incorporation in transition zone minerals: wadsleyite, ringwoodite and phase D using ERDA (elastic recoil detection analysis). Front. Earth Sci. 6, 75 (2018).

    Google Scholar 

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Acknowledgements

We thank H. Fischer for preparation of cell assemblies, R. Njul for preparation of thin-section samples, D. Wiesner and F. Ferreira for measurements of EBSD patterns of the samples and H. Keppler for measurements of water in the samples by using FTIR, at the Bayerisches Geoinstitut. We also appreciate D. J. Frost and T. Katsura for valuable discussion on this topic and T. Withers for useful comments on the manuscript. This research was supported by the Grants-in-Aid of the German Research Foundation (no. IS350/1-1) to T.I. and the Kakenhi Grants JP15H05748 and JP20H00187 from Japan Society for the Promotion of Science to E.O. E.O. was supported also by the research award from the Alexander von Humboldt foundation.

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Both authors identified the research topic, designed the experiments, conducted high-pressure experiments and analysed the run products. Both authors discussed the results and wrote the manuscript.

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Correspondence to Takayuki Ishii.

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Peer review information Nature Geoscience thanks Jean-Philippe Perrillat and the other, anonymous, reviewer(s) for their contribution to the peer review of this work. Primary Handling Editor: Rebecca Neely.

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Extended data

Extended Data Fig. 1 Schematic drawings of cell assemblies.

Water-partitioning experiments between a, forsterite and hydrous phase A and b, wadsleyite and hydrous phase A. In the experiments for forsterite, oriented crystals with 200 μm a axis × 400 μm b axis × 400 μm c axis were put in the capsules as shown in the right capsule in Extended Data Fig. 1a.

Extended Data Fig. 2 Representative X-ray diffraction patterns of the recovered samples at the surrounding part of the single crystals.

a, 10 GPa and 800 °C (S7423). b, 12 GPa and 900 °C (H5073). Fo, forsterite; Wd, wadsleyite; Cen, clinoenstatite; PhA, hydrous phase A.

Extended Data Table 1 Experimental summary.

Experimental conditions and results of phase identification and water contents in single crystals.

Extended Data Table 2 Water contents of forsterite and wadsleyite.

Details of FTIR measurements of forsterite and wadsleyite single crystals.

Supplementary information

Supplementary Information

Supplementary Figs. 1–3.

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Ishii, T., Ohtani, E. Dry metastable olivine and slab deformation in a wet subducting slab. Nat. Geosci. 14, 526–530 (2021). https://doi.org/10.1038/s41561-021-00756-7

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