Earthquake-induced transformation of the lower crust

Abstract

The structural and metamorphic evolution of the lower crust has direct effects on the lithospheric response to plate tectonic processes involved in orogeny, including subsidence of sedimentary basins, stability of deep mountain roots and extension of high-topography regions. Recent research shows that before orogeny most of the lower crust is dry, impermeable and mechanically strong1. During an orogenic event, the evolution of the lower crust is controlled by infiltration of fluids along localized shear or fracture zones. In the Bergen Arcs of Western Norway, shear zones initiate as faults generated by lower-crustal earthquakes. Seismic slip in the dry lower crust requires stresses at a level that can only be sustained over short timescales or local weakening mechanisms. However, normal earthquake activity in the seismogenic zone produces stress pulses that drive aftershocks in the lower crust2. Here we show that the volume of lower crust affected by such aftershocks is substantial and that fluid-driven associated metamorphic and structural transformations of the lower crust follow these earthquakes. This provides a ‘top-down’ effect on crustal geodynamics and connects processes operating at very different timescales.

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Fig. 1: Earthquakes and aftershocks in the lower crust.
Fig. 2: Fossil earthquakes in the Bergen Arcs.
Fig. 3: Transformation of the lower crust.

References

  1. 1.

    Jamtveit, B., Austrheim, H. & Putnis, A. Disequilibrium metamorphism of stressed lithosphere. Earth Sci. Rev. 154, 1–13 (2016).

    CAS  Article  Google Scholar 

  2. 2.

    Ben-Zion, Y. & Lyakhovsky, V. Analysis of aftershocks in a lithospheric model with seismogenic zone governed by damage rheology. Geophys. J. Int. 165, 197–210 (2006).

    ADS  Article  Google Scholar 

  3. 3.

    Chen, W. P. & Molnar, P. Focal depths of intracontinental and intraplate earthquakes and their implication for the thermal and mechanical properties of the lithosphere. J. Geophys. Res. 88, 4183–4214 (1983).

    ADS  Article  Google Scholar 

  4. 4.

    Jackson, J. Strength of the continental lithosphere: time to abandon the jelly sandwich? GSA Today 12, 4–9 (2002).

    Article  Google Scholar 

  5. 5.

    Rudnick, R. L. & Fountain, D. M. Nature and composition of the continental lower crust. Rev. Geophys. 33, 267–309 (1995).

    ADS  Article  Google Scholar 

  6. 6.

    Copley, A., Avouac, J.-P., Hollingsworth, J. & Leprince, S. The 2001 M W 7.6 Bhuj earthquake, low fault friction and the upper crustal support of plate driving forces in India. J. Geophys. Res. 116, B08405 (2011).

    ADS  Article  Google Scholar 

  7. 7.

    Craig, T. J., Copley, A. & Jackson, J. Thermal and tectonic consequences of India underthrusting Tibet. Earth Planet. Sci. Lett. 353–354, 231–239 (2012).

    Article  Google Scholar 

  8. 8.

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

    ADS  CAS  Article  PubMed  Google Scholar 

  9. 9.

    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).

    ADS  Article  Google Scholar 

  10. 10.

    Moecher, D. P. & Steltenpohl, M. G. Direct calculation of rupture depth for an exhumed paleoseismogenic fault from mylonitic pseudotachylyte. Geology 37, 999–1002 (2009).

    ADS  Article  Google Scholar 

  11. 11.

    Kohlstedt, D. L., Evans, B. & Mackwell, S. J. Strength of the lithosphere—constraints imposed by laboratory experiments. J. Geophys. Res. 100, 17587–17602 (1995).

    ADS  Article  Google Scholar 

  12. 12.

    Ellis, S. & Stöckhert, B. Elevated stresses and creep rates beneath the brittle-ductile transition caused by seismic faulting in the upper crust. J. Geophys. Res. 109, B05407 (2004).

    ADS  Article  Google Scholar 

  13. 13.

    Hawemann, F., Mancktelow, N. S., Wex, S., Camacho, A. & Pennaccioni, G. Pseudotachylyte as field evidence for lower crustal earthquakes during the intracontinental Petermann Orogeny (Musgrave Block, Central Australia). Solid Earth Discuss. (submitted); preprint at https://doi.org/10.5194/se-2017-123 (2018).

  14. 14.

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

    ADS  Article  Google Scholar 

  15. 15.

    Hillers, G., Ben-Zion, Y. & Mai, P. M. Seismicity on a fault controlled by rate- and state dependent friction with spatial variations of the critical slip distance. J. Geophys. Res. 111, B01403 (2006).

    ADS  Google Scholar 

  16. 16.

    Jiang, J. & Lapusta, N. Connecting depth limits of interseismic locking, microseismicity, and large earthquakes in models of long-term fault slip. J. Geophys. Res. 122, 6491–6523 (2017).

  17. 17.

    Bingen, B., Davis, W. J. & Austrheim, H. Zircon U-Pb geochronology in the Bergen arc eclogites and their Proterozoic protoliths, and implications for the pre-Scandian evolution of the Caledonides in western Norway. Geol. Soc. Am. Bull. 113, 640–649 (2001).

    ADS  CAS  Article  Google Scholar 

  18. 18.

    Bhowany, K. et al. Phase equilibria modelling constraints on P-T conditions during fluid catalysed conversion of granulite to eclogite in the Bergen Arcs, Norway. J. Metamorph. Geol. 36, 315–342 (2018).

    ADS  Article  Google Scholar 

  19. 19.

    Austrheim, H. et al. Microstructural records of seismic slip. Sci. Adv. 3, e1602067 (2017).

    ADS  Article  PubMed  PubMed Central  Google Scholar 

  20. 20.

    Mitchell, T. M., Toy, V., Di Toro, G., Renner, J. & Sibson, R. H. Fault welding by pseudotachylyte formation. Geology 44, 1059–1062 (2016).

    ADS  Article  Google Scholar 

  21. 21.

    Ben-Zion, Y. Collective behavior of earthquakes and faults: continuum-discrete transitions, progressive evolutionary changes and different dynamic regimes. Rev. Geophys. 46, RG4006 (2008).

    ADS  Article  Google Scholar 

  22. 22.

    Ben-Zion, Y. & Ampuero, J.-P. Seismic radiation from regions sustaining material damage. Geophys. J. Int. 178, 1351–1356 (2009).

    ADS  Article  Google Scholar 

  23. 23.

    Ben-Zion, Y. & Zhu, L. Potency-magnitude scaling relations for southern California earthquakes with 1.0<ML<7.0. Geophys. J. Int. 148, F1–F5 (2002).

    Article  Google Scholar 

  24. 24.

    Edwards, B., Allmann, B., Fah, D. & Clinton, J. Automatic computation of moment magnitudes for small earthquakes and the scaling of local to moment magnitude. Geophys. J. Int. 183, 407–420 (2010).

    ADS  Article  Google Scholar 

  25. 25.

    Båth, M. Lateral inhomogeneities in the upper mantle. Tectonophysics 2, 483–514 (1965).

    ADS  Article  Google Scholar 

  26. 26.

    Zaliapin, I. & Ben-Zion, Y. Y. Earthquake clusters in southern California. I: Identification and stability. J. Geophys. Res. 118, 2847–2864 (2013).

    ADS  Article  Google Scholar 

  27. 27.

    Zaliapin, I. & Ben-Zion, Y. A global classification and characterization of earthquake clusters. Geophys. J. Int. 207, 608–634 (2016).

    ADS  Article  Google Scholar 

  28. 28.

    McNamara, D. E. et al. Source modeling of the 2015 M W 7.8 Nepal (Gorkha) earthquake sequence: implications for geodynamics and earthquake hazards. Tectonophysics 714–715, 21–30 (2017).

    Article  Google Scholar 

  29. 29.

    Wells, D. L. & Coppersmith, K. J. New empirical relationships among magnitude, rupture length, rupture width, rupture area, and surface displacement. Bull. Seismol. Soc. Am. 84, 974–1002 (1994).

    Google Scholar 

  30. 30.

    Putnis, A., Jamtveit, B. & Austrheim, H. Metamorphic processes and seismicity: the Bergen Arcs as a natural laboratory. J. Petrol. 58, 1871–1898 (2017).

    ADS  CAS  Article  Google Scholar 

  31. 31.

    Yardley, B. W. D. The role of water in the evolution of the continental crust. J. Geol. Soc. Lond. 166, 585–600 (2009).

    Article  Google Scholar 

  32. 32.

    Munz, I. A., Yardley, B. W. D., Banks, D. & Wayne, D. Deep penetration of sedimentary fluids in basement rocks from Southern Norway—evidence from hydrocarbon and brine inclusions in quartz veins. Geochim. Cosmochim. Acta 59, 239–254 (1995).

    ADS  CAS  Article  Google Scholar 

  33. 33.

    Austrheim, H. Fluid and deformation induced metamorphic processes around Moho beneath continent collision zones: Examples from the exposed root zone of the Caledonian mountain belt, W-Norway. Tectonophysics 609, 620–635 (2013).

    ADS  Article  Google Scholar 

  34. 34.

    Rybacki, E. & Dresen, G. Deformation mechanism maps for feldspar rocks. Tectonophysics 382, 173–187 (2004).

    ADS  CAS  Article  Google Scholar 

  35. 35.

    Azuma, S., Katayama, I. & Nakakuki, T. Rheological decoupling at the Moho and implications to Venusian tectonics. Sci. Rep. 4, 4403 (2014).

    ADS  Article  PubMed  PubMed Central  Google Scholar 

  36. 36.

    Tullis, J. & Yund, R. The brittle–ductile transition in feldspar aggregates. An experimental study. Int. Geophys. 51, 89–117 (1992).

    Article  Google Scholar 

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Acknowledgements

This project has been supported by the European Union’s Horizon 2020 Research and Innovation Programme under ERC Advanced Grant Agreement number 669972, ‘Disequilibrium Metamorphism’ (‘DIME’; to B.J.), and by the Norwegian Research Council grant number 250661 (‘HADES’; to F.R.). Y.B.-Z. acknowledges support from the National Science Foundation (grant EAR-1722561). The paper benefited from discussions with and comments by I. Zaliapin, J. Jackson, A. Putnis, S. Schmalholz, S. Xu, P. Meakin and J. Platt.

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Nature thanks B. Yardley and the other anonymous reviewer(s) for their contribution to the peer review of this work.

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All authors designed this study. B.J. and Y.B.-Z. wrote the manuscript with input from F.R. and H.A., H.A. and B.J. conducted the field studies, F.R. designed the figures. Y.B.-Z. and F.R. derived the theoretical estimates of earthquake quantities motivated by the idea of ‘seismic index’ proposed by H.A.

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Correspondence to Bjørn Jamtveit.

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Extended data figures and tables

Extended Data Fig. 1 Rheology of dry anorthite.

Shear stress versus temperature diagram contoured with respect to strain rate.

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Jamtveit, B., Ben-Zion, Y., Renard, F. et al. Earthquake-induced transformation of the lower crust. Nature 556, 487–491 (2018). https://doi.org/10.1038/s41586-018-0045-y

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