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Fossil intermediate-depth earthquakes in subducting slabs linked to differential stress release

Abstract

The cause of intermediate-depth (50–300 km) seismicity in subduction zones is uncertain. It is typically attributed either to rock embrittlement associated with fluid pressurization, or to thermal runaway instabilities. Here we document glassy pseudotachylyte fault rocks—the products of frictional melting during coseismic faulting—in the Lanzo Massif ophiolite in the Italian Western Alps. These pseudotachylytes formed at subduction-zone depths of 60–70 km in poorly hydrated to dry oceanic gabbro and mantle peridotite. This rock suite is a fossil analogue to an oceanic lithospheric mantle that undergoes present-day subduction. The pseudotachylytes locally preserve high-pressure minerals that indicate an intermediate-depth seismic environment. These pseudotachylytes are important because they are hosted in a near-anhydrous lithosphere free of coeval ductile deformation, which excludes an origin by dehydration embrittlement or thermal runaway processes. Instead, our observations indicate that seismicity in cold subducting slabs can be explained by the release of differential stresses accumulated in strong dry metastable rocks.

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Fig. 1: Pseudotachylyte in eclogitized metaperidotite.
Fig. 2: Pseudotachylyte in peridotite and metagabbro.
Fig. 3: Pseudotachylyte in anhydrous gabbro.
Fig. 4: Pseudotachylyte in metaperidotite–metagabbro.
Fig. 5: Locating the seismic activity of Moncuni in a subducting slab.

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References

  1. Kirby, S. H., Engdahl, E. R. & Denlinger R. in Subduction: Top to Bottom (eds G. E. Bebout et al.) 195–214 (Geophysics Monograph Series 96, AGU, Washington DC, 1996).

  2. 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. 108, 2030 (2003).

    Google Scholar 

  3. Frohlich, C. The nature of deep-focus earthquakes. Ann. Rev. Earth Planet. Sci. 17, 227–254 (1989).

    Article  Google Scholar 

  4. Abers, G. A. Seismic low-velocity layer at the top of subducting slabs: observations, predictions, and systematics. Phys. Earth Planet. Int. 149, 7–29 (2005).

    Article  Google Scholar 

  5. Bostock, M. G. The Moho in subduction zones. Tectonophysics 609, 547–557 (2013).

    Article  Google Scholar 

  6. Audet, P., Bostock, M. G., Christensen, N. I. & Peacock, S. M. Seismic evidence for overpressured subducted oceanic crust and megathrust fault sealing. Nature 457, 76–78 (2009).

    Article  Google Scholar 

  7. Kodaira, S. et al. High pore fluid pressure may cause silent slip in the Nankai Trough. Science 304, 1295–1298 (2004).

    Article  Google Scholar 

  8. Ogawa, M. Shear instability in a viscoelastic material as the cause of deep focus earthquakes. J. Geophys. Res. 92, 13801–13810 (1987).

    Article  Google Scholar 

  9. Braeck, S. & Podladchikov, Y. Y. Spontaneous thermal runaway as an ultimate failure mechanism of materials. Phys. Rev. Lett. 98, 095504 (2007).

    Article  Google Scholar 

  10. Kelemen, P. B. & Hirth, G. A. Periodic shear-heating mechanism for intermediate-depth earthquakes in the mantle. Nature 446, 787–790 (2007).

    Article  Google Scholar 

  11. John, T. et al. Generation of intermediate-depth earthquakes by self-localizing thermal runaway. Nat. Geosci. 2, 137–140 (2009).

    Article  Google Scholar 

  12. Thielmann, M., Rozel, A., Kaus, B. J. P. & Ricard, Y. Intermediate-depth earthquake generation and shear zone formation caused by grain size reduction and shear heating. Geology 43, 791–794 (2015).

    Article  Google Scholar 

  13. Jung, H., Green, H. W. II & Dobrzhinetskaya, L. F. Intermediate-depth earthquake faulting by dehydration embrittlement with negative volume change. Nature 428, 545–549 (2004).

    Article  Google Scholar 

  14. Okazaki, K. & Hirth, G. Dehydration of lawsonite could directly trigger earthquakes in subducting oceanic crust. Nature 530, 81–85 (2016).

    Article  Google Scholar 

  15. Green, H. W. II, Shi, F., Bozhilov, K., Xia, G. & Reches, Z. Phase transformation and nanometric flow cause extreme weakening during fault slip. Nat. Geosci. 8, 484–490 (2015).

    Article  Google Scholar 

  16. Austrheim, H. & Boundy, T. M. Pseudotachylytes generated during seismic faulting and eclogitization of the deep crust. Science 265, 82–83 (1994).

    Article  Google Scholar 

  17. Austrheim, H. et al. Fragmentation of wall rock garnets during deep crustal earthquakes. Sci. Adv. 3, e1602067 (2017).

    Article  Google Scholar 

  18. John, T. & Schenk, V. Interrelations between intermediate-depth earthquakes and fluid flow within subducting oceanic plates: constraints from eclogite facies pseudotachylytes. Geology 34, 557–560 (2006).

    Article  Google Scholar 

  19. Austrheim, H. & Andersen, T. B. Pseudotachylytes from Corsica: fossil earthquakes from a subduction complex. Terra Nova 16, 193–197 (2004).

    Article  Google Scholar 

  20. Andersen, T. B. & Austrheim, H. Fossil earthquakes recorded by pseudotachylytes in mantle peridotite from the Alpine subduction complex of Corsica. Earth Planet. Sci. Lett. 242, 58–72 (2006).

    Article  Google Scholar 

  21. Deseta, N., Andersen, T. B. & Ashwal, L. D. A weakening mechanism for intermediate-depth seismicity? Detailed petrographic and microtextural observations from blueschist facies pseudotachylytes, Cape Corse, Corsica. Tectonophysics 610, 138–149 (2014).

    Article  Google Scholar 

  22. Deseta, N., Ashwal, L. D. & Andersen, T. B. Initiating intermediate-depth earthquakes: insights from a HPLT ophiolite from Corsica. Lithos 206–207, 127–146 (2014).

    Article  Google Scholar 

  23. Piccardo, G. B., Ranalli, G. & Guarnieri, L. Seismogenic shear zones in the lithospheric mantle: ultramafic pseudotachylytes in the Lanzo peridotite (Western Alps, NW Italy). J. Petrol. 51, 81–100 (2010).

    Article  Google Scholar 

  24. Piccardo, G. B., Ranalli, G., Marasco, M. & Padovano, M. Ultramafic pseudotachylytes in the Mt. Moncuni peridotite (Lanzo Massif, Western Alps): tectonic evolution and upper mantle seismicity. Period. Mineral. 76, 181–197 (2007).

    Google Scholar 

  25. Vitale Brovarone, A. et al. Stacking and metamorphism of continuous segments of subducted lithosphere in a high-pressure wedge: the example of Alpine Corsica (France). Earth Sci. Rev. 116, 35–56 (2013).

    Article  Google Scholar 

  26. Debret, B., Nicollet, C., Andreani, M., Schwartz, S. & Godard, M. Three steps of serpentinization in an eclogitized oceanic serpentinization front (Lanzo Massif – Western Alps). J. Metam. Geol. 31, 165–186 (2013).

    Article  Google Scholar 

  27. Kienast, J. R. & Pognante, U. Chloritoid-bearing assemblages in eclogitised metagabbros of the Lanzo peridotite body (Western Italian Alps). Lithos 21, 1–11 (1988).

    Article  Google Scholar 

  28. Pelletier, L. & Müntener, O. High pressure metamorphism of the Lanzo peridotite and its oceanic cover, and some consequences for the Sesia–Lanzo zone (northwestern Italian Alps). Lithos 90, 111–130 (2006).

    Article  Google Scholar 

  29. Rubatto, D., Müntener, O., Barnhoorn, A. & Gregory, C. Dissolution–reprecipitation of zircon at low-temperature, high-pressure conditions (Lanzo Massif, Italy). Am. Mineral. 93, 1519–1529 (2008).

    Article  Google Scholar 

  30. Scambelluri, M., Muentener, O., Ottolini, L., Pettke, T. & Vannucci, R. The fate of B, Cl and Li in the subducted oceanic mantle and in the antigorite-breakdown fluids. Earth Planet. Sci. Lett. 222, 217–234 (2004).

    Article  Google Scholar 

  31. Lund, M. G. & Austrheim, H. High-pressure metamorphism and deep-crustal seismicity: evidence from contemporaneous formation of pseudotachylytes and eclogite facies coronas. Tectonophysics 372, 59–83 (2003).

    Article  Google Scholar 

  32. Lund, M. G., Austrheim, H. & Herambert, M. Earthquakes in the deep continental crust — insights from studies on exhumed high-pressure rocks. Geophys. J. Int. 158, 569–576 (2004).

    Article  Google Scholar 

  33. Abers, G. A., Nakajima, J., van Keken, P. E., Kita, S. & Hacker, B. R. Thermal–petrological controls on the location of earthquakes within subducting plates. Earth Planet. Sci. Lett. 369–370, 178–187 (2013).

    Article  Google Scholar 

  34. Prieto, G. A., Florez, M. & Barrett, S. A. Seismic evidence for thermal runaway during intermediate-depth earthquake rupture. Geophys. Res. Lett. 40, 6064–6068 (2013).

    Article  Google Scholar 

  35. Prieto, G. A., Froment, B., Yu, C., Poli, P. & Abercrombie, R. Earthquake rupture below the brittle–ductile transition in continental lithospheric mantle. Sci. Adv. 3, e1602042 (2017).

    Article  Google Scholar 

  36. Andersen, T. B., Mair, K., Austrheim, H., Podladchikov, Y. Y. & Vrijmoed, J. C. Stress release in exhumed intermediate and deep earthquakes determined from ultramafic pseudotachylyte. Geology 36, 995–998 (2008).

    Article  Google Scholar 

  37. Dobson, D., Meredith, P. & Boon, S. Simulation of subduction zone seismicity by dehydration of serpentine. Science 298, 1407–1410 (2002).

    Article  Google Scholar 

  38. Gasc, J. et al. Simultaneous acoustic emissions monitoring and synchrotron X-ray diffraction at high pressure and temperature: calibration and application to serpentinite dehydration. Phys. Earth Planet. Int. 189, 121–133 (2011).

    Article  Google Scholar 

  39. Proctor, B. & Hirth, G. Role of pore fluid pressure on transient strength changes and fabric development during serpentine dehydration at mantle conditions: Implications for subduction-zone seismicity. Earth Planet. Sci. Lett. 421, 1–12 (2015).

    Article  Google Scholar 

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

    Article  Google Scholar 

  41. Faccenda, M. & Mancktelow, N. S. Fluid flow during unbending: implications for slab hydration, intermediate-depth earthquakes and deep fluid subduction. Tectonophysics 494, 149–154 (2010).

    Article  Google Scholar 

  42. Kita, S., Okada, T., Nakajima, J., Matsuzawa, T. & Hasegawa, A. Existence of a seismic belt in the upper plane of the double seismic zone extending in the along-arc direction at depths of 70–100 km beneath NE Japan. Geophys. Res. Lett. 33, L24310 (2006).

    Article  Google Scholar 

  43. Rondenay, S., Abers, G. A. & van Keken, P. E. Seismic imaging of subduction zone metamorphism. Geology 36, 275–278 (2008).

    Article  Google Scholar 

  44. Kawakatsu, H. & Watada, S. Seismic evidence for deep-water transportation in the mantle. Science 316, 1468–1471 (2007).

    Article  Google Scholar 

  45. Kato, A. et al. Variations of fluid pressure within the subducting oceanic crust and slow earthquakes. Geophys. Res. Lett. 37, L14310 (2010).

    Google Scholar 

  46. Angiboust, S., Wolf, S., Burov, E., Agard, P. & Yamato, P. Effect of fluid circulation on subduction interface tectonic processes: insights from thermo-mechanical numerical modelling. Earth Planet. Sci. Lett. 357–358, 238–248 (2012).

    Article  Google Scholar 

  47. Ide, S., Shelly, D. R. & Beroza, G. C. The mechanism of deep low frequency earthquakes: further evidence that deep non-volcanic tremor is generated by shear slip on the plate interface. Geophys. Res. Lett. 34, L03308 (2007).

    Article  Google Scholar 

  48. Faccenda, M., Burlini, L., Gerya, T. & Mainprice, D. Fault-induced seismic anisotropy by hydration in subducting oceanic plates. Nature 455, 1097–1101 (2008).

    Article  Google Scholar 

  49. Angiboust, S. & Agard, P. Initial water budget: the key to detaching large volumes of eclogitized oceanic crust along the subduction channel? Lithos 120, 453–474 (2010).

    Article  Google Scholar 

  50. Angiboust, S., Agard, P., Yamato, P. & Raimbourg, H. Eclogite breccias in a subducted ophiolite. A record of intermediate-depth earthquakes? Geology 40, 707–710 (2012).

    Article  Google Scholar 

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Acknowledgements

We greatly benefitted from discussions with P. Agard, T. Ferrand, A. Schubnel, O. Onken, E. Cannaò and S. Poli and from constructive comments by T. B. Andersen. We thank M. Kendrick for revising the pre-submission manuscript, and A. Risplendente and L. Negretti for technical assistance during the SEM and wavelength-dispersive spectrometry microprobe work. M.S. and M.G. acknowledge funding by the People Programme (Marie Curie Actions, European Union’s Seventh Framework Programme FP7/2007—2013) to the Initial Training Network ZIP (Zooming In-between Plates, REA grant agreement no. 604713). Discussions within ZIP stimulated this work. M.S. also acknowledges support from the Italian MIUR and the University of Genova. G.P. acknowledges funding of the University of Padova.

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M.S., G.P. and O.P. wrote the paper. M.S., G.P. and M.G. carried out the fieldwork, and the petrographic and microstructural study. M.B. did the field-emission SEM and EBSD work. O.P. did the TEM work. F.N. did the XRD and Raman analysis. M.S. and G.P. developed the concept.

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Correspondence to Marco Scambelluri.

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Supplementary Information

Supplementary Information

This file provides extended discussion and figures of: (1) the regional geological setting of the rocks studied (Supplementary Figure 1); (2) the microstructures of pseudotachylyte and cataclasite in gabbro (Supplementary Section 1); and (3) the microstructures of pseudotachylyte in eclogitic metagabbro and meta-peridotite (Supplementary Section 2)

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Scambelluri, M., Pennacchioni, G., Gilio, M. et al. Fossil intermediate-depth earthquakes in subducting slabs linked to differential stress release. Nature Geosci 10, 960–966 (2017). https://doi.org/10.1038/s41561-017-0010-7

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