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Network of off-axis melt bodies at the East Pacific Rise

Nature Geoscience volume 5, pages 279–283 (2012)Cite this article

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Abstract

Magmatic accretion of new oceanic crust at intermediate- to fast-spreading mid-ocean ridges occurs along a narrow axial zone. This zone is characterized by molten sills in the crust that are emplaced within about 3 km of the ridge axis1 and overlie a zone of elevated temperatures and partial melt2,3,4. There are disparate indications of off-axis magmatism5,6,7,8 and lavas erupted in the near-axis region are more compositionally variable than in the axial zone9. Here we present three-dimensional seismic reflection images from the fast-spreading East Pacific Rise that reveal a network of sills 4 to 8 km east of the ridge axis. Our crustal model, constrained using seismic velocity and attenuation data, shows that the sills are located outside of the main axial zone of crustal accretion, and above a region containing partial melt. We infer that the sills represent sites of sustained off-axis magmatism. Pockets of melt extend from the off-axis sills to the axial zone and may represent melt migration pathways. These pathways could promote mixing between enriched off-axis melts and normal on-axis melts, contributing to the compositional variability of the near-axis lavas9. We suggest that off-axis magmatism occurs preferentially, but not exclusively, where pre-existing fractures inherited from offsets of the spreading axis promote melt transport from the mantle into the crust.

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Figure 1: Bathymetry of the East Pacific Rise and its flanks between 9° 28′ N and 10° 00′ N latitude from cruise MGL0812.
Figure 2: Seismic reflection energy and vertical sections through the off-axis network.
Figure 3: Seismic sections illustrating the polarity of the main reflections.
Figure 4: Wide-angle seismic data showing attenuation in the OAML region.

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References

  1. 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 

  2. Dunn, R. A., Toomey, D. R. & 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 

  3. Wilcock, W. S. D., Solomon, S. C., Purdy, G. M. & Toomey, D. R. The seismic attenuation structure of a fast-spreading mid-ocean ridge. Science 258, 1470–1474 (1992).

    Article  Google Scholar 

  4. Crawford, W. C. & Webb, S. C. Variations in the distribution of magma in the lower crust and at the Moho beneath the East Pacific Rise at 9° –10° N. Earth Planet. Sci. Lett. 203, 117–130 (2002).

    Article  Google Scholar 

  5. Durant, D. T. & Toomey, D. R. Evidence and implications of crustal magmatism on the flanks of the East Pacific Rise. Earth Planet. Sci. Lett. 287, 130–136 (2009).

    Article  Google Scholar 

  6. Garmany, J. Accumulations of melt at the base of young oceanic crust. Nature 340, 628–632 (1989).

    Article  Google Scholar 

  7. Haymon, R. M., Macdonald, K. C., Benjamin, S. B. & Ehrhardt, C. J. Manifestations of hydrothermal discharge from young abyssal hills on the fast-spreading East Pacific Rise flank. Geology 33, 153–156 (2005).

    Article  Google Scholar 

  8. Goldstein, S. J., Perfit, M. R., Batiza, R., Fornari, D. J. & Murrell, M. T. Off-axis volcanism at the East Pacific Rise detected by uranium-series dating of basalts. Nature 367, 157–159 (1994).

    Article  Google Scholar 

  9. Perfit, M. R. et al. Small-scale spatial and temporal variations in mid-ocean ridge crest magmatic processes. Geology 22, 375–379 (1994).

    Article  Google Scholar 

  10. Haymon, R. M. et al. Hydrothermal vent distribution along the East Pacific Rise crest (9° 09′–54′ N) and its relationship to magmatic and tectonic processes on fast-spreading mid-ocean ridges. Earth Planet. Sci. Lett. 104, 513–534 (1991).

    Article  Google Scholar 

  11. Carbotte, S. M. & Macdonald, K. C. East Pacific Rise 8°–10° 30′ N: evolution of ridge segment and discontinuities from SeaMARC II and three-dimensional magnetic studies. J. Geophys. Res. 97, 6959–6982 (1992).

    Article  Google Scholar 

  12. Canales, J. P., Detrick, R. S., Toomey, D. R. & Wilcock, W. S. D. Segment-scale variations in the crustal structure of 150–300 kyr old fast spreading oceanic crust (East Pacific Rise, 8° 15′ N–10°15′ N) from wide-angle seismic refraction profiles. Geophys. J. Int. 152, 766–794 (2003).

    Article  Google Scholar 

  13. Kent, G. M., Harding, A. J. & Orcutt, J. A. 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 

  14. Collier, J. S. & Singh, S. C. Detailed structure of the top of the melt body beneath the East Pacific Rise at 9° 40′ N from waveform inversion of seismic reflection data. J. Geophys. Res. 102, 20287–20304 (1997).

    Article  Google Scholar 

  15. Haymon, R. M. et al. Volcanic eruption of the mid-ocean ridge along the East Pacific Rise crest at 9° 45–52′ N: Direct submersible observations of seafloor phenomena associated with an eruption event in April, 1991. Earth Planet. Sci. Lett. 119, 85–101 (1993).

    Google Scholar 

  16. Soule, S. A., Fornari, D. J., Perfit, M. R. & Rubin, K. H. New insights into mid-ocean ridge volcanic processes from the 2005–2006 eruption of the East Pacific Rise, 9° 46′ N–9° 56′ N. Geology 35, 1079–1082 (2007).

    Article  Google Scholar 

  17. Mutter, J. C., Carbotte, S., Nedimović, M. R., Canales, J. P. & Carton, H. Seismic imaging in three dimensions on the East Pacific Rise. Eos Trans. AGU 90, 374–375 (2009).

    Article  Google Scholar 

  18. Toomey, D. R., Jousselin, D., Dunn, R. A., Wilcock, W. S. D. & Detrick, R. S. Skew of mantle upwelling beneath the East Pacific Rise governs segmentation. Nature 446, 409–414 (2007).

    Article  Google Scholar 

  19. Hussenoeder, S. A., Collins, J. A., Kent, G. M. & Detrick, R. S. The TERA Group. Seismic analysis of the axial magma chamber reflector along the southern East Pacific Rise from conventional reflection profiling. J. Geophys. Res. 101, 22087–22105 (1996).

    Article  Google Scholar 

  20. Phipps Morgan, J. & Chen, Y. J. Dependence of ridge-axis morphology on magma supply and spreading rate. Nature 364, 706–708 (1993).

    Article  Google Scholar 

  21. Waters, C. L., Sims, K. W. W., Perfit, M. R., Blichert-Toft, J. & Blusztajn, J. Perspective on the genesis of E-MORB from chemical and isotopic heterogeneity at 9–10° N East Pacific Rise. J. Petrol. 52, 565–602 (2011).

    Article  Google Scholar 

  22. Hebert, L. B. & Montesi, L. G. J. Generation of permeability barriers during melt extraction at mid-ocean ridges. Geochem. Geophys. Geosyst. 11, Q12008 (2010).

    Article  Google Scholar 

  23. Wilcock, W. S. D., Purdy, G. M., Solomon, S. C., DuBois, D. L. & Toomey, D. R. Microearthquakes on and near the East Pacific Rise, 9°–10° N. Geophys. Res. Lett. 19, 2131–2134 (1992).

    Article  Google Scholar 

  24. Sohn, R. A. & Sims, K. W. W. Bending as a mechanism for triggering off-axis volcanism on the East Pacific Rise. Geology 33, 93–96 (2005).

    Article  Google Scholar 

  25. Smith, M. C. et al. Magmatic processes and segmentation at a fast spreading mid-ocean ridge: Detailed investigation of an axial discontinuity on the East Pacific Rise crest at 9° 37′ N. Geochem. Geophys. Geosyst. 2, 1040 (2001).

    Article  Google Scholar 

  26. White, S. M., Haymon, R. M., Fornari, D. J., Perfit, M. R. & Macdonald, K. C. Correlation between volcanic and tectonic segmentation of fast-spreading ridges: Evidence from volcanic structures and lava flow morphology on the East Pacific Rise at 9°–10° N. J. Geophys. Res. 107, 2173 (2002).

    Article  Google Scholar 

  27. Soule, S. A., Escartı´n, J. & Fornari, D. A record of eruption and intrusion at a fast spreading ridge axis: Axial summit trough of the East Pacific Rise 9–10° N. Geochem. Geophys. Geosyst. 10, Q10T07 (2009).

    Article  Google Scholar 

  28. Goss, A. R. et al. Geochemistry of lavas from the 2005–2006 eruption at the East Pacific Rise, 9° 46′ N–9° 56′ N: Implications for ridge crest plumbing and decadal changes in magma chamber compositions. Geochem. Geophys. Geosyst. 11, Q05T09 (2010).

    Article  Google Scholar 

  29. Turcotte, D. L. & Schubert, G. Geodynamics (Cambridge Univ. Press, 2002).

    Book  Google Scholar 

  30. Korenaga, J. et al. Crustal structure of the southeast Greenland margin from joint refraction and reflection seismic tomography. J. Geophys. Res. 105, 21591–21614 (2000).

    Article  Google Scholar 

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Acknowledgements

This research was funded by the US National Science Foundation. We thank the RV M.G. Langseth’s Captain M. Landow, crew, and technical staff led by R. Steinhaus for their efforts, which made possible the success of cruise MGL0812. We thank S.A. Soule for providing digital information about the AST and 2005–2006 eruption shown in Fig. 1 and 2, and for stimulating discussions during the preparation of this manuscript. We thank D.R. Toomey for his reviews, which improved the manuscript.

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Authors and Affiliations

  1. Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02540, USA

    J. P. Canales

  2. Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York 10964, USA

    H. Carton, S. M. Carbotte, J. C. Mutter, M. R. Nedimović, M. Marjanović & K. Newman

  3. Department of Earth Sciences, Dalhousie University, Halifax, Nova Scotia B3H4J1, Canada

    M. R. Nedimović & O. Aghaei

  4. Department of Geology and Geophysics, Massachusetts Institute of Technology-Woods Hole Oceanographic Institution Joint Program in Oceanography, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02540, USA

    M. Xu

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Contributions

J.P.C. Field program co-leader. MCS data processing and visualization. OBS seismic data analysis and tomography modelling. Geological interpretation. Wrote manuscript. H.C. Data acquisition and quality control. Data processing. Contributed to data processing strategy, interpretation and manuscript writing. S.M.C. Program inception and planning leader. Field program co-leader. Geological interpretation. Contributed to manuscript writing. J.C.M. Program inception. Field program leader. Contributed to interpretation and manuscript writing. M.R.N. Field program co-leader. Contributed to data processing strategy, interpretation and manuscript writing. M.X. Data acquisition and quality control. Data processing. O.A. Data acquisition and quality control. Contributed to data processing strategy. M.M. Data acquisition and quality control. K.N. Data acquisition and quality control.

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Correspondence to J. P. Canales.

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Canales, J., Carton, H., Carbotte, S. et al. Network of off-axis melt bodies at the East Pacific Rise. Nature Geosci 5, 279–283 (2012). https://doi.org/10.1038/ngeo1377

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