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Lower crustal crystallization and melt evolution at mid-ocean ridges

Nature Geoscience volume 5, pages 651–655 (2012)Cite this article

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Abstract

Mid-ocean ridge magmas are produced when Earth’s mantle rises beneath the ridge axis and melts owing to a decrease in pressure. This magma subsequently undergoes cooling and crystallization to form the oceanic crust. However, there is no consensus on where within the crust or upper mantle crystallization occurs1,2,3,4,5. Here we provide direct geochemical evidence for the depths of crystallization beneath ridge axes of two spreading centres located in the Pacific Ocean: the fast-spreading-rate East Pacific Rise and intermediate-spreading-rate Juan de Fuca Ridge. Specifically, we measure volatile concentrations in olivine-hosted melt inclusions to derive vapour-saturation pressures and to calculate crystallization depth. We also analyse the melt inclusions for major and trace element concentrations, allowing us to compare the distributions of crystallization and to track the evolution of the melt during ascent through the oceanic crust. We find that most crystallization occurs within a seismically imaged melt lens located in the shallow crust at both ridges, but over 25% of the melt inclusions have crystallization pressures consistent with formation in the lower oceanic crust. Furthermore, our results suggest that melts formed beneath the ridge axis can be efficiently mixed and undergo olivine crystallization in the mantle, before ascent into the ocean crust.

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Figure 1: Volatile contents of MOR melt inclusions and glasses.
Figure 2: Distribution of crystallization at the EPR and JdFR.
Figure 3: Major elements versus depth.
Figure 4: Schematic diagram of crustal accretion at fast-spreading centres based on melt inclusions analyses.

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References

  1. Nicolas, A. & Reuber, I. A new magma chamber model based on structural studies in the Oman ophiolite. Tectonophysics 151, 87–105 (1988).

    Article  Google Scholar 

  2. Quick, J. & Denlinger, R. Ductile deformation and the origin of layered gabbro in ophiolites. J. Geophys. Res. 98, 14015–14027 (1993).

    Article  Google Scholar 

  3. Phipps Morgan, J. & Chen, Y. The genesis of oceanic crust: Magma injection, hydrothermal circulation, and crustal flow. J. Geophys. Res. 98, 6283–6297 (1993).

    Article  Google Scholar 

  4. Kelemen, P., Koga, K. & Shimizu, N. Geochemistry of gabbro sills in the crust–mantle transition zone of the Oman ophiolite: Implications for the origin of the oceanic lower crust. Earth Planet. Sci. Lett. 146, 475–488 (1997).

    Article  Google Scholar 

  5. Kelemen, P. & Aharonov, E. in Faulting and Magmatism at Mid-ocean Ridges Vol. 106 (eds Buck, W. R., Delaney, T., Karson, A. & Lagabrielle, Y.) 267–289 (1998).

    Google Scholar 

  6. Detrick, R. S. et al. Multi-channel seismic imaging of a crustal magma chamber along the East Pacific Rise. Nature 326, 35–41 (1987).

    Article  Google Scholar 

  7. Kent, G., Harding, A. & Orcutt, J. Distribution of magma beneath the East Pacific Rise between the Clipperton transform and the 9 17’ N Deval from forward modeling of common depth point data. J. Geophys. Res. 98, 13945–13969 (1993).

    Article  Google Scholar 

  8. Canales, J. P. et al. Upper crustal structure and axial topography at intermediate spreading ridges: Seismic constraints from the southern Juan de Fuca Ridge. J. Geophys. Res. 110, 1–27 (2005).

    Article  Google Scholar 

  9. 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 

  10. O’Hara, M. & Mathews, R. Geochemical evolution in an advancing, periodically replenished, periodically tapped, continuously fractionated magma chamber. J. Geol. Soc. Lond. 138, 237–277 (1981).

    Article  Google Scholar 

  11. Batiza, R. et al. Steady and non-steady state magma chambers below the East Pacific Rise. Geophys. Res. Lett. 23, 221–224 (1996).

    Article  Google Scholar 

  12. Sinton, J. & Detrick, R. Mid-ocean ridge magma chambers. J. Geophys. Res. 97, 197–216 (1992).

    Article  Google Scholar 

  13. Crawford, W., Webb, S. & Hildebrand, J. Constraints on melt in the lower crust and Moho at the East Pacific Rise, 9 deg 48 min N, using seafloor compliance measurements. J. Geophys. Res. 104, 2923–2939 (1999).

    Article  Google Scholar 

  14. Dixon, J. E. & Stolper, E. M. An Experimental study of water and carbon dioxide solubilities in mid-ocean ridge basaltic liquids. Part II: Applications to degassing. J. Petrol. 36, 1633–1646 (1995).

    Google Scholar 

  15. Bottinga, Y. & Javoy, M. Mid-ocean ridge basalt degassing: Bubble nucleation. J. Geophys. Res. 95, 5125–5131 (1990).

    Article  Google Scholar 

  16. Bottinga, Y. & Javoy, M. MORB degassing: Evolution of CO2 . Earth Planet. Sci. Lett. 95, 215–225 (1989).

    Article  Google Scholar 

  17. Dixon, J., Stolper, E. & Delaney, J. R. Infrared spectroscopic measurements of CO2 and H2O in Juan de Fuca Ridge basaltic glasses. Earth Planet. Sci. Lett. 90, 87–104 (1988).

    Article  Google Scholar 

  18. Le Roux, P., Shirey, S., Hauri, E., Perfit, M. & Bender, J. The effects of variable sources, processes and contaminants on the composition of northern EPR MORB (8–10° N and 12–14° N): Evidence from volatiles (H2O,CO2, S) and halogens (F, Cl). Earth Planet. Sci. Lett. 251, 209–231 (2006).

    Article  Google Scholar 

  19. Soule, S. A. et al. CO2 variability in mid-ocean ridge basalts from syn-emplacement degassing: Constraints on eruption dynamics. Earth Planet. Sci. Lett. 327–328, 39–49 (2012).

    Article  Google Scholar 

  20. Saal, A., Hauri, E., Langmuir, C. & Perfit, M. Vapour undersaturation in primitive mid-ocean-ridge basalt and the volatile content of Earth’s upper mantle. Nature 419, 451–455 (2002).

    Article  Google Scholar 

  21. Shaw, A., Behn, M., Humphris, S., Sohn, R. & Gregg, P. Deep pooling of low degree melts and volatile fluxes at the 85° E segment of the Gakkel Ridge: Evidence from olivine-hosted melt inclusions and glasses. Earth Planet. Sci. Lett. 289, 311–322 (2010).

    Article  Google Scholar 

  22. Rubin, K. & Sinton, J. Inferences on mid-ocean ridge thermal and magmatic structure from MORB compositions. Earth Planet. Sci. Lett. 260, 257–276 (2007).

    Article  Google Scholar 

  23. Shimizu, N. The geochemistry of olivine-hosted melt inclusions in a FAMOUS basalt ALV519-4-1. Phys. Earth Planet. Int. 107, 183–201 (1998).

    Article  Google Scholar 

  24. Dunn, R., Toomey, D. & Solomon, S. C. Three-dimensional seismic structure and physical properties of the crust and shallow mantle beneath the East Pacific Rise at 9 30′ N. J. Geophys. Res. 105, 23537–23555 (2000).

    Article  Google Scholar 

  25. Nedimović, M. R. et al. Frozen magma lenses below the oceanic crust. Nature 436, 1149–1152 (2005).

    Article  Google Scholar 

  26. Karson, J., Collins, J. & Casey, J. Geologic and seismic velocity structure of the crust mantle transition in the Bay of Islands ophiolite complex. J. Geophys. Res. 89, 6126–6138 (1984).

    Article  Google Scholar 

  27. Klein, E. in The Crust: Treatise on Geochemistry Vol. 3 (ed. Rudnick, R. L.) 433–464 (2005).

    Google Scholar 

  28. Sparks, D. W. & Parmentier, E. M. Melt extraction from the mantle beneath spreading centers. Earth Planet. Sci. Lett. 105, 368–377 (1991).

    Article  Google Scholar 

  29. Shaw, A. M., Hauri, E. H., Fischer, T. P., Hilton, D. R. & Kelley, K. A. Hydrogen isotopes in Mariana arc melt inclusions: Implications for subduction dehydration and the deep-Earth water cycle. Earth Planet. Sci. Lett. 275, 138–145 (2008).

    Article  Google Scholar 

  30. Newman, S. & Lowenstern, J. VC: A silicate melt-H2O–CO2 solution model written in Visual Basic for Excel*. Comput. Geosci. 28, 597–604 (2002).

    Article  Google Scholar 

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Acknowledgements

We thank R. Hervig, B. Montelone, N. Shimizu and N. Chatterjee for their assistance with geochemical analyses. M. Behn and A. Soule are thanked for their comments and discussions. This research was supported by the National Science Foundation (EAR-0646694) and the WHOI Deep Ocean Exploration Institute/Ocean Ridge Initiative.

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  1. Department of Geology and Geophysics, Woods Hole Oceanographic Institution, 360 Woods Hole Road, Woods Hole, Massachusetts 02543, USA

    V. D. Wanless & A. M. Shaw

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  1. V. D. Wanless
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Contributions

V.D.W. prepared samples. V.D.W. and A.M.S. collected geochemical data. V.D.W. and A.M.S. worked together on data interpretation and preparation of the manuscript.

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Correspondence to V. D. Wanless.

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Wanless, V., Shaw, A. Lower crustal crystallization and melt evolution at mid-ocean ridges. Nature Geosci 5, 651–655 (2012). https://doi.org/10.1038/ngeo1552

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