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Ocean rises are products of variable mantle composition, temperature and focused melting

Nature Geoscience volume 8, pages 68–74 (2015)Cite this article

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Abstract

Ocean ridges, where Earth’s tectonic plates are pulled apart, range from more than 5-km depth in the Arctic to 750 m above sea level in Iceland. This huge relief is generally attributed to mantle plumes underlying mantle hotspots—areas of voluminous volcanism marked by ocean islands. The plumes are thought to feed the mantle beneath adjacent ocean ridges. This process results in thickened crust and ridge elevation to form ocean rises. The composition of mid-ocean ridge basalt, a direct function of mantle composition and temperature, varies systematically along ocean rises, but in a unique way for each different rise. Here we use thermodynamic calculations of melt-evolution pathways to show that variations in both mantle temperature and source composition are required to explain the chemical make-up of rise basalts. Thus, lateral gradients in mantle temperature cannot be uniquely determined from basalt chemistry, and ocean rises can be supported by chemically buoyant mantle or by robust mantle plumes. Our calculations also indicate that melt is conserved and focused by percolative flow towards the overlying ridge, progressively interacting with the mantle to shallow depth. We conclude that most mantle melting occurs by an overlooked mechanism, focused melting, whereas fractional melting is a secondary process that is important largely at shallow depth.

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Figure 1: Na8.0, Fe8.0,8.07Sr/8.06Sr and depth along axis projected onto longitude or latitude for four major ocean rises.
Figure 2: Na8.0 and Fe8.0 plots for ocean rises.
Figure 3: Melting paths for MORB generation.
Figure 4: Focused-melting model.
Figure 5: Results of melt runs shown in Fig. 3b versus melt–rock ratio and remaining asthenosphere in the melting column.

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References

  1. Melson, W. G., Vallier, T. L., Wright, T. L., Byerly, G. & Nelen, J. Chemical diversity of abyssal volcanic glass erupted along Pacific, Atlantic, and Indian Ocean sea-floor spreading centers. Geophys. Pac. Ocean Basin Margin 19, 351–368 (1976).

    Google Scholar 

  2. Bryan, W. B. & Dick, H. J. B. Contrasted abyssal basalt liquidus trends: Evidence for mantle major element heterogeneity. Earth Planet. Sci. Lett. 58, 15–26 (1982).

    Article  Google Scholar 

  3. Schilling, J-G. et al. Petrologic and geochemical variations along the Mid-Atlantic Ridge from 29° N to 73° N. Am. J. Sci. 283, 510–586 (1983).

    Article  Google Scholar 

  4. Dick, H. J. B., Fisher, R. L. & Bryan, W. B. Mineralogic variability of the uppermost mantle along mid-ocean ridges. Earth Planet. Sci. Lett. 69, 88–106 (1984).

    Article  Google Scholar 

  5. Klein, E. M. & Langmuir, C. H. Global correlations of ocean ridge basalt chemistry with axial depth and crustal thickness. J. Geophys. Res. 92, 8089–8115 (1987).

    Article  Google Scholar 

  6. Gale, A., Langmuir, C. H. & Dalton, C. A. The global systematics of ocean ridge basalts and their origin. J. Petrol. 55, 1051–1082 (2014).

    Article  Google Scholar 

  7. Cannat, M. et al. Ultramafic and gabbroic exposures at the Mid-Atlantic Ridge: Geologic mapping in the 15° N region. Tectonophysics 279, 193–213 (1997).

    Article  Google Scholar 

  8. Small, C. & Danyushevsky, L. V. Plate kinematic explanation for mid-oceanic ridge depth discontinuities. Geology 31, 399–402 (2003).

    Article  Google Scholar 

  9. Niu, Y. & O’Hara, M. J. Global correlations of ocean ridge basalt chemistry with axial depth: A new perspective. J. Petrol. 49, 633–664 (2008).

    Article  Google Scholar 

  10. Presnall, D. C. & Gudfinnsson, G. H. Origin of the oceanic lithosphere. J. Petrol. 49, 615–632 (2008).

    Article  Google Scholar 

  11. Wilson, J. T. A possible origin of the Hawaiian Islands. Can. J. Phys. 41, 863–870 (1963).

    Article  Google Scholar 

  12. Zhou, H-y. & Dick, H. J. B. Thin crust as evidence for depleted mantle supporting the Marion Rise. Nature 494, 195–200 (2013).

    Article  Google Scholar 

  13. Ito, G. & Behn, M. D. Magmatic and tectonic extension at mid-ocean ridges: 2. Origin of axial morphology. Geochem. Geophys. Geosyst. 9, Q09O12 (2008).

    Article  Google Scholar 

  14. Weir, R. W. et al. Crustal structure of the northern Reykjanes Ridge and Reykjanes Peninsula, southwest Iceland. J. Geophys. Res. 106, 6347–6368 (2001).

    Article  Google Scholar 

  15. Schilling, J-G. Iceland mantle plume: Geochemical evidence along Reykjanes Ridge. Nature 242, 565–571 (1973).

    Article  Google Scholar 

  16. White, W. M., Schilling, J-G. & Hart, S. R. Evidence for the Azores mantle plume from strontium isotope geochemistry of the Central North Atlantic. Nature 263, 659–663 (1976).

    Article  Google Scholar 

  17. Hart, R., Dymond, J., Hogan, L. & Schilling, J-G. Mantle plume noble gas component in glassy basalts from Reykjanes Ridge. Nature 305, 403–407 (1983).

    Article  Google Scholar 

  18. Salters, V. J. M. & Stracke, A. Composition of the depleted mantle. Geochem. Geophys. Geosyst. 5, Q05B07 (2004).

    Article  Google Scholar 

  19. Zindler, A. & Hart, S. Chemical geodynamics. Annu. Rev. Earth Planet. Sci. 14, 493–571 (1986).

    Article  Google Scholar 

  20. Klein, E. M. & Langmuir, C. H. Local versus global variations in ocean ridge basalt composition: A reply. J. Geophys. Res. 96, 4241–4252 (1989).

    Article  Google Scholar 

  21. Kinzler, R. J. & Grove, T. Primary magmas of mid-ocean ridge basalts 2. Applications. J. Geophys. Res. 97, 6907–6926 (1992).

    Article  Google Scholar 

  22. Niu, Y. & Batiza, R. Chemical variation trends at fast and slow-spreading mid-ocean ridges. J. Geophys. Res. 98, 7887–7903 (1993).

    Article  Google Scholar 

  23. Kushiro, I. The system forsterite-diopside-silica with and without water at high pressures. Am. J. Sci. 267-A, 269–294 (1969).

    Google Scholar 

  24. Presnall, D. C. & Hoover, J. D. Composition and depth of origin of primary mid-ocean ridge basalts. Contrib. Mineral. Petrol. 87, 170–178 (1984).

    Article  Google Scholar 

  25. Dick, H. J. B. The Origin and Emplacement of the Josephine Peridotite 400 PhD thesis, Yale Univ. (1976)

  26. Dick, H. J. B. & Natland, J. H. in Scientific Results Vol. 147 (eds Gillis, K., Mevel, C. & Allan, J.) 103–134 (Texas A&M University, 1996).

    Google Scholar 

  27. Dick, H. J. B. & Natland, J. R. An Offset Drilled Mantle Section: Evidence for Focused Melt Flow Beneath the East Pacific Rise from ODP Leg 147 Abstract vol. 25, 444 (Geological Society of America, 1993).

    Google Scholar 

  28. Kelemen, P. B., Shimizu, N. & Salters, V. J. M. Extraction of mid-ocean-ridge basalt from the upwelling mantle by focused flow of melt in dunite channels. Nature 375, 747–753 (1995).

    Article  Google Scholar 

  29. Asimow, P. D. A model that reconciles major- and trace-element data from abyssal peridotites. Earth Planet. Sci. Lett. 169, 303–319 (1999).

    Article  Google Scholar 

  30. Ghiorso, M. S. & Sack, R. O. Chemical mass-transfer in magmatic processes. 4. A revised and internally consistent thermodynamic model for the interpolation and extrapolation of liquid–solid equilibria in magmatic systems at elevated-temperatures and pressures. Contrib. Mineral. Petrol. 119, 197–212 (1995).

    Article  Google Scholar 

  31. Johnson, K. T. M., Dick, H. J. B. & Shimizu, N. Melting in the oceanic upper mantle: An ion microprobe study of diopsides in abyssal peridotites. J. Geophys. Res. 95, 2661–2678 (1990).

    Article  Google Scholar 

  32. Dick, H. J. B. in Magmatism in the Ocean Basins, Geological Society Special Publication No. 42 (eds Saunders, A. D. & Norry, M. J.) 71–105 (Geological Society of London, 1989).

    Google Scholar 

  33. Dick, H. J. B., Tivey, M. A. & Tucholke, B. E. Plutonic foundation of a slow-spreading ridge segment: Oceanic core complex at Kane Megamullion, 23° 30′ N, 45° 20′ W. Geochem. Geophys. Geosyst. 9, Q05014 (2008).

    Article  Google Scholar 

  34. Sauter, D. et al. Focused magmatism versus amagmatic spreading along the ultra-slow spreading Southwest Indian Ridge: Evidence from TOBI side scan sonar imagery. Geochem. Geophys. Geosyst. 5, Q10K09 (2004).

    Google Scholar 

  35. Spiegelman, M. Geochemical consequences of melt transport in 2-D: The sensitivity of trace elements to mantle. Earth Planet. Sci. Lett. 139, 115–132 (1996).

    Article  Google Scholar 

  36. Asimow, P. D. & Stolper, E. M. Steady-state mantle-melt interactions in one dimension: I. Equilibrium transport and melt focusing. J. Petrol. 40, 475–494 (1999).

    Article  Google Scholar 

  37. Ghiorso, M. S., Hirschmann, M. M., Reiners, P. W. & Kress, V. C. III The pMELTS: A revision of MELTS for improved calculation of phase relations and major element partitioning related to partial melting of the mantle to 3 GPa. Geochem. Geophys. Geosyst. 3, 1–36 (2002).

    Article  Google Scholar 

  38. Wasylenki, L. E., Baker, M. B., Kent, A. J. R. & Stolper, E. M. Near-solidus melting of the shallow upper mantle: Partial melting experiments on depleted peridotite. J. Petrol. 44, 1163–1191 (2003).

    Article  Google Scholar 

  39. Baker, M. B. & Stolper, E. M. Determining the composition of high-pressure mantle melts using diamond aggregates. Geochim. Cosmochim. Acta 58, 2811–2827 (1994).

    Article  Google Scholar 

  40. McKenzie, D. & Bickle, M. J. The volume and composition of melt generated by extension of the lithosphere. J. Petrol. 29, 625–679 (1988).

    Article  Google Scholar 

  41. Asimow, P. D. & Langmuir, C. H. The importance of water to oceanic melting regimes. Nature 421, 815–820 (2003).

    Article  Google Scholar 

  42. Niu, Y. & Batiza, R. Chemical variation trends at fast and slow spreading mid-ocean ridges. J. Geophys. Res. 98, 7887–7902 (1993).

    Article  Google Scholar 

  43. Kelemen, P. B., Hirth, G., Shimizu, N., Speigelman, M. & Dick, H. A review of melt migration processes in the adiabatically upwelling mantle beneath oceanic spreading ridges. Phil. Trans. R. Soc. Lond. A 355, 283–318 (1997).

    Article  Google Scholar 

  44. Dantas, C. et al. Pyroxenites from the Southwest Indian Ridge, 9–16° E; cumulates from incremental melt fractions produced at the top of a cold melting regime. J. Petrol. 48, 647–660 (2007).

    Article  Google Scholar 

  45. Dick, H. J. B., Lissenberg, C. J. & Warren, J. Mantle melting, melt transport and delivery beneath a slow-spreading ridge: The Paleo-MAR from 23° 15′ N to 23° 45′ N. J. Petrol. 51, 425–467 (2010).

    Article  Google Scholar 

  46. Warren, J. M. & Shimizu, N. Cryptic variations in abyssal peridotite compositions: Evidence for shallow-level melt infiltration in the oceanic lithosphere. J. Petrol. 51, 395–423 (2010).

    Article  Google Scholar 

  47. Asimow, P. D., Dixon, J. E. & Langmuir, C. H. A hydrous melting and fractionation model for mid-ocean ridge basalts: Application to the Mid-Atlantic Ridge near the Azores. Geochem. Geophys. Geosyst. 5, Q01E16 (2004).

    Article  Google Scholar 

  48. Standish, J. J. The Influence of Ridge Geometry at the Ultraslow-Spreading Southwest Indian Ridge (9°–25° E): Basalt Composition Sensitivity to Variations in Source and Process PhD thesis, Woods Hole Oceanographic Institution and the Massachusetts Institute of Technology (2006)

  49. Langmuir, C. H., Klein, E. M. & Plank, T. in Mantle Flow and Melt Generation at Mid-Ocean Ridges Vol. 71 (eds Phipps Morgan, J., Blackman, D. K. & Sinton, J. M.) 183–280 (American Geophysical Union, 1992).

    Google Scholar 

  50. Ghiorso, M. S. Chemical mass transfer in magmatic processes I. Thermodynamic relations and numerical algorithms. Contrib. Mineral. Petrol. 90, 107–120 (1985).

    Article  Google Scholar 

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Acknowledgements

We would like to acknowledge M. Hirschman for his invaluable assistance in learning how to use pMELTS, input and criticism from E. Tursack, and numerous conversations on the subject with G. Gaetani, M. Behn, N. Shimizu, P. Kelemen, J. Natland and G. Hirth. P. Asimow, M. Ghiorso and V. Salters all provided helpful reviews that improved the manuscript both in clarity and thinking. Y. Liu and J. Wang checked our pMELTS calculations, using different conditions to test the robustness of our results. The National Science Foundation financially supported H.J.B.D. (NSF/OCE 08.0278.025). H.Z. would like to acknowledge the support of the Chinese National Key Basic Research Program (2012CB417300), China Ocean Mineral Resources Research and Development Association.

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Authors and Affiliations

  1. Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA

    Henry J. B. Dick

  2. State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092, China

    Huaiyang Zhou

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H.J.B.D. performed the initial modelling and wrote the paper with input from H.Z. H.Z. and his students carried out additional modelling for comparison to that presented in the paper to test the robustness of the conclusions. Interpretation of the results of the modelling and preparation of the figures and illustrations were performed jointly by the co-authors.

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Correspondence to Henry J. B. Dick or Huaiyang Zhou.

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Dick, H., Zhou, H. Ocean rises are products of variable mantle composition, temperature and focused melting. Nature Geosci 8, 68–74 (2015). https://doi.org/10.1038/ngeo2318

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