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Fault-controlled hydration of the upper mantle during continental rifting

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Abstract

Water and carbon are transferred from the ocean to the mantle in a process that alters mantle peridotite to create serpentinite and supports diverse ecosystems1. Serpentinized mantle rocks are found beneath the sea floor at slow- to ultraslow-spreading mid-ocean ridges1 and are thought to be present at about half the world’s rifted margins2,3. Serpentinite is also inferred to exist in the downgoing plate at subduction zones4, where it may trigger arc magmatism or hydrate the deep Earth. Water is thought to reach the mantle via active faults3,4. Here we show that serpentinization at the rifted continental margin offshore from western Spain was probably initiated when the whole crust cooled to become brittle and deformation was focused along large normal faults. We use seismic tomography to image the three-dimensional distribution of serpentinization in the mantle and find that the local volume of serpentinite beneath thinned, brittle crust is related to the amount of displacement along each fault. This implies that sea water reaches the mantle only when the faults are active. We estimate the fluid flux along the faults and find it is comparable to that inferred for mid-ocean ridge hydrothermal systems. We conclude that brittle processes in the crust may ultimately control the global flux of sea water into the Earth.

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Figure 1: Comparison between the crustal thickness at which complete crustal embrittlement is predicted to occur3 and the maximum crustal thickness observed above or juxtaposed against serpentinized mantle at various North Atlantic magma-poor margins8.
Figure 2: Compressional (P-) wave velocities superimposed on coincident seismic reflection profiles illustrate the concentration of serpentinization beneath the hanging wall of normal faults (expansion of 6.5–7.5 km s−1 iso-velocity interval).
Figure 3: Water volume and amount of serpentinization associated with faults on the seismic reflection profile shown in Fig. 2b, assuming a two-dimensional structure.

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Change history

  • 26 May 2016

    In the version of the Letter originally published, the following reference was mistakenly omitted in the Methods: '29. Minshull, T. A., Sinha, M. C. & Peirce, C. Multi-disciplinary, sub-seabed geophysical imaging. Sea Technol. 46, 27–31 (2005).' This should have been cited after '(OBSs)' in the sentence 'A grid of 72 ocean bottom instruments, comprising 44 four-component ocean bottom seismometers (OBSs) and 28 ocean bottom hydrophones (OBHs) was deployed on the seabed for three months to record these shots, with sample rates of 250 Hz and 200 Hz, respectively'. The original refs 29–33 have been renumbered accordingly. This has been corrected in the online versions of the Letter.

References

  1. Fruh-Green, G. L. et al. Serpentinization of oceanic peridotites: implications for geochemical cycles and biological activity. Subseafloor Biosph. Mid-Ocean Ranges 144, 119–136 (2004).

    Article  Google Scholar 

  2. Whitmarsh, R. B., Manatschal, G. & Minshull, T. A. Evolution of magma-poor continental margins from rifting to seafloor spreading. Nature 413, 150–154 (2001).

    Article  Google Scholar 

  3. Perez-Gussinye, M. & Reston, T. J. Rheological evolution during extension at nonvolcanic rifted margins: onset of serpentinization and development of detachments leading to continental breakup. J. Geophys. Res. 106, 3961–3975 (2001).

    Article  Google Scholar 

  4. Ranero, C. R. et al. Bending-related faulting and mantle serpentinization at the Middle America trench. Nature 425, 367–373 (2003).

    Article  Google Scholar 

  5. Manning, C. E. & Ingebritsen, S. E. Permeability of the continental crust: implications of geothermal data and metamorphic systems. Rev. Geophys. 37, 127–150 (1999).

    Article  Google Scholar 

  6. Sibson, R. H. Fluid involvement in normal faulting. J. Geodynam. 29, 469–499 (2000).

    Article  Google Scholar 

  7. Faulkner, D. R. et al. A review of recent developments concerning the structure, mechanics and fluid flow properties of fault zones. J. Struct. Geol. 32, 1557–1575 (2010).

    Article  Google Scholar 

  8. Reston, T. J. The structure, evolution and symmetry of the magma-poor rifted margins of the North and Central Atlantic: a synthesis. Tectonophysics 468, 6–27 (2009).

    Article  Google Scholar 

  9. O’reilly, B. M. et al. Crustal thinning, mantle exhumation and serpentinization in the Porcupine Basin, offshore Ireland: evidence from wide-angle seismic data. J. Geol. Soc. 163, 775–787 (2006).

    Article  Google Scholar 

  10. Funck, T. et al. Crustal structure of the ocean-continent transition at Flemish Cap: seismic refraction results. J. Geophys. Res. 108, 2531 (2003).

    Article  Google Scholar 

  11. Wu, Y. et al. Crustal structure of the central Nova Scotia margin off eastern Canada. Geophys. J. Int. 166, 878–906 (2006).

    Article  Google Scholar 

  12. Rupke, L. H. et al. Interrelation between rifting, faulting, sedimentation, and mantle serpentinization during continental margin formation-including examples from the Norwegian Sea. Geochem. Geophys. Geosyst. 14, 4351–4369 (2013).

    Article  Google Scholar 

  13. Reston, T. J. et al. Movement along a low-angle normal fault: the S reflector west of Spain. Geochem. Geophys. Geosyst. 8, Q06002 (2007).

    Article  Google Scholar 

  14. Escartin, J., Hirth, G. & Evans, B. Effects of serpentinization on the lithospheric strength and the style of normal faulting at slow-spreading ridges. Earth Planet. Sci. Lett. 151, 181–189 (1997).

    Article  Google Scholar 

  15. Zelt, C. A. et al. Assessment of crustal velocity models using seismic refraction and reflection tomography. Geophys. J. Int. 153, 609–626 (2003).

    Article  Google Scholar 

  16. Christensen, N. I. Serpentinites, peridotites, and seismology. Int. Geol. Rev. 46, 795–816 (2004).

    Article  Google Scholar 

  17. Ranero, C. R. & Perez-Gussinye, M. Sequential faulting explains the asymmetry and extension discrepancy of conjugate margins. Nature 468, 294–299 (2010).

    Article  Google Scholar 

  18. Buck, W. R. Flexural rotation of normal faults. Tectonics 7, 959–973 (1988).

    Article  Google Scholar 

  19. Kelley, D. S., Baross, J. A. & Delaney, J. R. Volcanoes, fluids, and life at mid-ocean ridge spreading centers. Annu. Rev. Earth Planet. Sci. 30, 385–491 (2002).

    Article  Google Scholar 

  20. Coogan, L. A. et al. Chemical and thermal constraints on focussed fluid flow in the lower oceanic crust. Am. J. Sci. 306, 389–427 (2006).

    Google Scholar 

  21. Fruh-Green, G. L. et al. 30,000 years of hydrothermal activity at the Lost City vent field. Science 301, 495–498 (2003).

    Article  Google Scholar 

  22. Reynolds, S. J. & Lister, G. S. Structural aspects of fluid-rock interactions in detachment zones. Geology 15, 362–366 (1987).

    Article  Google Scholar 

  23. Hannington, M. D. et al. Comparison of the TAG mound and stockwork complex with Cyprus-type massive sulphide deposit. Proc. Ocean Drill. Program Sci. Results 158, 389–415 (1998).

    Google Scholar 

  24. Baker, E. T. Hydrothermal cooling of midocean ridge axes: do measured and modeled heat fluxes agree? Earth Planet. Sci. Lett. 263, 40–150 (2007).

    Article  Google Scholar 

  25. Sibson, R. H. Generation of pseudotachylyte by ancient seismic faulting. Geophys. J. R. Astron. Soc. 43, 775–794 (1975).

    Article  Google Scholar 

  26. Emmanuel, S. & Berkowitz, B. Suppression and stimulation of seafloor hydrothermal convection by exothermic mineral hydration. Earth Planet. Sci. Lett. 243, 657–668 (2006).

    Article  Google Scholar 

  27. Macdonald, A. H. & Fyfe, W. S. Rate of serpentinization in seafloor environments. Tectonophysics 116, 123–135 (1985).

    Article  Google Scholar 

  28. Borgmeyer, A. L. Three-Dimensional Geometries of Rifting on a Hyperextended Margin—Interpretation of Seismic Reflection Profiles from the Deep Galicia Basin, Iberia. MSc thesis, Rice Univ. (2010).

    Google Scholar 

  29. Minshull, T. A., Sinha, M. C. & Peirce, C. Multi-disciplinary, sub-seabed geophysical imaging. Sea Technol. 46, 27–31 (2005).

    Google Scholar 

  30. Zelt, C. A. & Barton, P. J. Three-dimensional seismic refraction tomography: a comparison of two methods applied to data from the Faeroe Basin. J. Geophys. Res. 103, 7187–7210 (1998).

    Article  Google Scholar 

  31. Carlson, R. L. & Miller, D. J. Mantle wedge water contents estimated from seismic velocities in partially serpentinized peridotites. Geophys. Rev. Lett. 30, 1250 (2003).

    Article  Google Scholar 

  32. Leythaeuser, T., Reston, T. J. & Minshull, T. A. Waveform inversion of the S reflector west of Spain: fine structure of a detachment fault. Geophys. Res. Lett. 32, L22304 (2005).

    Article  Google Scholar 

  33. Mansfield, C. & Cartwright, J. Fault growth by linkage: observations and implications from analogue models. J. Struct. Geol. 23, 745–763 (2001).

    Article  Google Scholar 

  34. Sutra, E. et al. Quantification and restoration of extensional deformation along the western Iberia and Newfoundland rifted margins. Geochem. Geophys. Geosyst. 14, 2575–2597 (2013).

    Article  Google Scholar 

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Acknowledgements

We thank all who sailed with us on RV Marcus Langseth and FS Poseidon for their hard work at sea, M. Karplus for assistance with detailed survey design, and A. Krabbenhoft for assistance with data processing. This research was supported by the US National Science Foundation (OCE-1031769), the UK Natural Environment Research Council (NE/E016502/1 and NE/E015883/1) and the GEOMAR Helmholtz Centre for Ocean Research. Ocean bottom instruments were provided by the UK Ocean Bottom Instrumentation Facility and by GEOMAR. T.A.M. was supported by a Wolfson Research Merit award.

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D.S.S., T.J.R., T.A.M., D.K., D.J.S., C.R., J.M.B. and J.K.M. designed the seismic experiment. D.S.S. led the survey on RV Marcus Langseth and D.K. and C.P. led the deployment and recovery of seafloor instruments aboard FS Poseidon. G.B. conducted the seismic data analysis, with R.G.D providing assistance. T.J.R. compiled the North Atlantic seismic profiles and M.P.-G. carried out the numerical modelling. G.B. and T.A.M. wrote the first draft of the paper and all authors contributed to subsequent revisions.

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Correspondence to T. A. Minshull.

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Bayrakci, G., Minshull, T., Sawyer, D. et al. Fault-controlled hydration of the upper mantle during continental rifting. Nature Geosci 9, 384–388 (2016). https://doi.org/10.1038/ngeo2671

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