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Spreading-rate dependence of melt extraction at mid-ocean ridges from mantle seismic refraction data

Abstract

A variety of observations indicate that mid-ocean ridges produce less crust at spreading rates below 20 mm yr-1 (refs 1–3), reflecting changes in fundamental ridge processes with decreasing spreading rate. The nature of these changes, however, remains uncertain, with end-member explanations being decreasing shallow melting3 or incomplete melt extraction2, each due to the influence of a thicker thermal lid. Here we present results of a seismic refraction experiment designed to study mid-ocean ridge processes by imaging residual mantle structure. Our results reveal an abrupt lateral change in bulk mantle seismic properties associated with a change from slow to ultraslow palaeo-spreading rate. Changes in mantle velocity gradient, basement topography and crustal thickness all correlate with this spreading-rate change. These observations can be explained by variations in melt extraction at the ridge, with a gabbroic phase preferentially retained in the mantle at slower spreading rates. The estimated volume of retained melt balances the 1.5-km difference in crustal thickness, suggesting that changes in spreading rate affect melt-extraction processes rather than total melting.

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Figure 1: FAIM experiment location and instrument layout.
Figure 2: Profiles from FAIM line 1 plotted at reduced travel time T (in seconds), using a reduction velocity V of 8.4 km s-1.
Figure 3: Velocity depth profiles at the line 1/line 2 crossing based on isotropic ray tracing of FAIM travel times.
Figure 4: Basement depth, spreading rate and crustal thickness.

References

  1. 1

    Chen, Y. J. Oceanic crustal thickness versus spreading rate. Geophys. Res. Lett. 19, 753–756 (1992)

    ADS  Article  Google Scholar 

  2. 2

    Cannat, M. How thick is the magmatic crust at slow spreading oceanic ridges? J. Geophys. Res. 101, 2847–2857 (1996)

    ADS  Article  Google Scholar 

  3. 3

    White, R. S., Minshull, T. A., Bickle, M. J. & Robinson, C. J. Melt generation at very slow-spreading oceanic ridges: Constraints from geochemical and geophysical data. J. Petrol. 42, 1171–1196 (2001)

    ADS  CAS  Article  Google Scholar 

  4. 4

    Langmuir, C. H., Klein, E. M. & Plank, T. in Mantle Flow and Melt Generation at Mid-Ocean Ridges (eds Morgan, J. P., Blackman, D. K. & Sinton, J. M.) 183–281 (Geophysical Monograph 71, American Geophysical Union, Washington DC, 1993)

    Google Scholar 

  5. 5

    Blackman, D. K. & Kendall, J.-M. Seismic anisotropy in the upper mantle. 2. Predictions for current plate boundary flow models. Geochem. Geophys. Geosyst. 3, doi:10.1029/ 2001GC000247 (2002)

  6. 6

    Müller, R. D., Walter, W. R., Royer, J.-Y., Gahagan, L. M. & Sclater, J. G. Digital isochrones of the world's ocean floor. J. Geophys. Res. 102, 3211–3214 (1997)

    ADS  Article  Google Scholar 

  7. 7

    Purdy, G. M. The seismic structure of 140 Myr old crust in the western central Atlantic Ocean. Geophys. J. R. Astron. Soc. 72, 115–137 (1983)

    ADS  Article  Google Scholar 

  8. 8

    Gaherty, J. B., Lizarralde, D., Collins, J. A., Hirth, G. & Kim, S. D. Mantle deformation during slow seafloor spreading constrained by observations of seismic anisotropy in the western Atlantic. Earth Planet. Sci. Lett. (in the press)

  9. 9

    Ben Ismail, W. & Mainprice, D. An olivine fabric database: an overview of upper mantle fabrics and seismic anisotropy. Tectonophysics 296, 145–157 (1998)

    ADS  Article  Google Scholar 

  10. 10

    Jordan, T. H. in The Mantle Sample: Inclusions in Kimberlites and Other Volcanics (eds Boyd, F. R. & Meyer, H. O. A.) 1–14 (American Geophysical Union, Washington DC, 1979)

    Book  Google Scholar 

  11. 11

    Stephen, R. A. Seismic anisotropy in the upper oceanic crust. J. Geophys. Res. 90, 11383–11396 (1985)

    ADS  Article  Google Scholar 

  12. 12

    Detrick, R. S., Toomey, D. R. & Collins, J. A. Three-dimensional upper crustal heterogeneity and anisotropy around Hole 504B from seismic tomography. J. Geophys. Res. 103, 30485–30504 (1998)

    ADS  Article  Google Scholar 

  13. 13

    Spiegelman, M. & Reynolds, J. R. Combined dynamic and geochemical evidence for convergent melt flow beneath the East Pacific Rise. Nature 402, 282–285 (1999)

    ADS  CAS  Article  Google Scholar 

  14. 14

    Grove, T. L., Kinzler, R. J. & Bryan, W. B. in Mantle Flow and Melt Generation at Mid-Ocean Ridges (eds Morgan, J. P., Blackman, D. K. & Sinton, J. M.) 281–310 (Geophysical Monograph 71, American Geophysical Union, Washington DC, 1993)

    Google Scholar 

  15. 15

    Dick, H. J. B. in Magmatism in the Ocean Basins (eds Sounders, A. D. & Norry, M. J.) 71–105 (Geol. Soc. Spec. Publ. No. 42, Bath, 1989)

    Google Scholar 

  16. 16

    Kelemen, P. B., Kikawa, E., Miller, D. J. & The Leg 209 Scientific Party. ODP Leg 209 drills into mantle peridotite along the mid-Atlantic ridge from 14°N to 16°N. JOIDES J. 30, 14–19 (2004)

    Google Scholar 

  17. 17

    Jokat, W. et al. Geophysical evidence for reduced melt production on the Arctic ultraslow Gakkel mid-ocean ridge. Nature 423, 962–965 (2003)

    ADS  CAS  Article  Google Scholar 

  18. 18

    Green, D. H. & Ringwood, A. E. An experimental investigation of gabbro to eclogite transformation and its petrological applications. Geochim. Cosmochim. Acta 31, 767–833 (1967)

    ADS  CAS  Article  Google Scholar 

  19. 19

    LADLE Study Group. A lithospheric seismic refraction profile in the western North Atlantic Ocean. Geophys. J. R. Astron. Soc. 75, 23–69 (1983)

    Article  Google Scholar 

  20. 20

    Asada, T. & Shimimura, H. Long-range refraction experiments in deep ocean. Tectonophysics 56, 67–82 (1979)

    ADS  Article  Google Scholar 

  21. 21

    Zverev, S. M. & Yaroshevskay, G. A. in Composition, Structure, and Dynamics of Lithosphere-Asthenosphere System (eds Fuchs, K. & Froidevaux, C.) 273–290 (Geodyn. Ser. 16, American Geophysical Union, 1987)

    Book  Google Scholar 

  22. 22

    Goodman, D. & Bibee, L. D. Measurements and modelling of possible mantle constituents from a long-line seismic refraction experiment in the West Philippine Basin. Geophys. J. Int. 106, 667–675 (1991)

    ADS  Article  Google Scholar 

  23. 23

    Chian, D., Hall, J. & Marillier, F. Lithospheric wide-angle seismic profiles using stacked airgun shots. Geophys. Res. Lett. 23, 2077–2080 (1996)

    ADS  Article  Google Scholar 

  24. 24

    Lizarralde, D. & Holbrook, W. S. US mid-Atlantic margin structure and early thermal evolution. J. Geophys. Res. 102, 22855–22875 (1997)

    ADS  CAS  Article  Google Scholar 

  25. 25

    Nakamura, Y., Donoho, P. L., Roper, P. H. & McPherson, P. M. Large-offset seismic surveying using ocean-bottom seismographs and air guns: Instrumentation and field technique. Geophysics 52, 1601–1611 (1987)

    ADS  Article  Google Scholar 

  26. 26

    Zelt, C. A. & Smith, R. B. Seismic traveltime inversion for 2-D crustal velocity structure. Geophys. J. Int. 108, 16–34 (1992)

    ADS  Article  Google Scholar 

  27. 27

    Grow, J. A. & Markl, R. G. IPOD-USGS multichannel seismic reflection profile from Cape Hatteras to the Mid-Atlantic ridge. Geology 5, 625–630 (1977)

    ADS  Article  Google Scholar 

  28. 28

    Christensen, N. I. Compressional wave velocities in possible mantle rocks to pressures of 30 kilobars. J. Geophys. Res. 79, 407–412 (1974)

    ADS  Article  Google Scholar 

  29. 29

    Greenfield, R. J. & Graham, E. K. Application of a simple relation for describing wave velocity as a function of pressure in rocks containing microcracks. J. Geophys. Res. 101, 5643–5652 (1996)

    ADS  Article  Google Scholar 

  30. 30

    Goes, S. & Govers, R. Shallow mantle temperatures under Europe from P and S wave tomography. J. Geophys. Res. 105, 11153–11169 (2000)

    ADS  Article  Google Scholar 

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Acknowledgements

We thank the Lamont Marine Office and the captain and crew of the RV Maurice Ewing for their efforts during cruise EW-0106. The efforts of J. DiBernardo, J. Stennet and J. Diebold are appreciated. This work was supported by the US National Science Foundation.

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Correspondence to Daniel Lizarralde.

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The authors declare that they have no competing financial interests.

Supplementary information

Supplementary Figures 1 - 11

Fig 1: Gravity model, seismically constrained crust.  Fig 2: Gravity model, isostatically balanced crust. Fig 3: Gravity model, retained melt to 30-km depth.  Fig 4: Gravity model, retained melt to 60-km depth.  Fig 5: Summary of gravity modeling results.  Fig 6: Melt extraction/retention cartoon.  Fig 7: Amplitude analysis for FAIM profile Tecate.  Fig 8: Portion of FAIM profile 420.  Fig 9: Portion of FAIM profile cass.  Fig 10: Portion of FAIM profile Tecate.  Fig 11: Model parameters and fit statistics for the crustal thickness measurements. (PDF 4258 kb)

Supplementary Information

a) Descriptions of crustal-thickness averages, FAIM Line 1 gravity profile and modeling, and a conceptual model for melt retention. b) Supplemental figure captions, Figures S1-S10. (DOC 36 kb)

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Lizarralde, D., Gaherty, J., Collins, J. et al. Spreading-rate dependence of melt extraction at mid-ocean ridges from mantle seismic refraction data. Nature 432, 744–747 (2004). https://doi.org/10.1038/nature03140

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