Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

The return of subducted continental crust in Samoan lavas

Abstract

Substantial quantities of terrigenous sediments are known to enter the mantle at subduction zones, but little is known about their fate in the mantle1. Subducted sediment may be entrained in buoyantly upwelling plumes and returned to the Earth’s surface at hotspots2,3,4,5, but the proportion of recycled sediment in the mantle is small, and clear examples of recycled sediment in hotspot lavas are rare6,7. Here we report remarkably enriched 87Sr/86Sr and 143Nd/144Nd isotope signatures in Samoan lavas from three dredge locations on the underwater flanks of Savai’i island, Western Samoa. The submarine Savai’i lavas represent the most extreme 87Sr/86Sr isotope compositions reported for ocean island basalts to date. The data are consistent with the presence of a recycled sediment component (with a composition similar to the upper continental crust) in the Samoan mantle. Trace-element data show affinities similar to those of the upper continental crustincluding exceptionally low Ce/Pb and Nb/U ratios8that complement the enriched 87Sr/86Sr and 143Nd/144Nd isotope signatures. The geochemical evidence from these Samoan lavas significantly redefines the composition of the EM2 (enriched mantle 2; ref. 9) mantle endmember, and points to the presence of an ancient recycled upper continental crust component in the Samoan mantle plume.

This is a preview of subscription content, access via your institution

Relevant articles

Open Access articles citing this article.

Access options

Buy article

Get time limited or full article access on ReadCube.

$32.00

All prices are NET prices.

Figure 1: 87 Sr/ 86 Sr and 143 Nd/ 144 Nd isotope ratios of new enriched Samoan lavas.
Figure 2: Primitive-mantle-normalized 27 trace-element patterns for the Samoan EM2 endmember.
Figure 3: 87 Sr/ 86 Sr and 143 Nd/ 144 Nd ratios suggest the presence of a UCC component in Samoan EM2 lavas.
Figure 4: ΔPb isotope compositions of Samoan lavas and marine sediment samples indicate that the Samoan EM2 lavas are not contaminated with modern marine sediment.

References

  1. Plank, T. & Langmuir, C. H. The chemical composition of subducting sediments and its consequences for the crust and mantle. Chem. Geol. 145, 325–394 (1998)

    Article  ADS  CAS  Google Scholar 

  2. Allegre, C. J. & Turcotte, D. L. Geodynamic mixing in the mesosphere boundary layer and the origin of oceanic islands. Geophys. Res. Lett. 12, 207–210 (1985)

    Article  ADS  CAS  Google Scholar 

  3. Cohen, R. S. & O'Nions, R. K. Identification of recycled continental material in the mantle from Sr, Nd and Pb isotope investigations. Earth Planet. Sci. Lett. 61, 73–84 (1982)

    Article  ADS  CAS  Google Scholar 

  4. Hawkesworth, C. J., Norry, M. J., Roddick, J. C. & Vollmer, R. 143Nd/144Nd and 87Sr/86Sr ratios from the Azores and their significance in LIL-element enriched mantle. Nature 280, 28–31 (1979)

    Article  ADS  CAS  Google Scholar 

  5. White, W. M. & Hofmann, A. W. Sr and Nd isotope geochemistry of oceanic basalts and mantle evolution. Nature 296, 821–825 (1982)

    Article  ADS  CAS  Google Scholar 

  6. White, W. M. & Duncan, R. A. in Earth Processes: Reading the Isotopic Code (eds Basu, A. & Hart, S. R.) 183–206 (Geophys. Monogr. 95, AGU, Washington DC, 1996)

    Google Scholar 

  7. Workman, R. K. et al. Recycled metasomatized lithosphere as the origin of the Enriched Mantle II (EM2) endmember: evidence from the Samoan volcanic chain. Geochem. Geophys. Geosyst. 5 doi: 10.1029/2003GC000623 (2004)

  8. Hofmann, A. W., Jochum, K. P., Seufert, M. & White, W. M. Nb and Pb in oceanic basalts: new constraints on mantle evolution. Earth Planet. Sci. Lett. 79, 33–45 (1986)

    Article  ADS  CAS  Google Scholar 

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

    Article  ADS  CAS  Google Scholar 

  10. Hofmann, A. W. & White, W. M. Mantle plumes from ancient oceanic crust. Earth Planet. Sci. Lett. 57, 421–436 (1982)

    Article  ADS  CAS  Google Scholar 

  11. Chase, C. G. Oceanic island Pb: two-stage histories and mantle evolution. Earth Planet. Sci. Lett. 52, 277–284 (1981)

    Article  ADS  CAS  Google Scholar 

  12. Zindler, A., Jagoutz, E. & Goldstein, S. Nd, Sr and Pb isotopic systematics in a three-component mantle: a new perspective. Nature 298, 519–523 (1982)

    Article  ADS  CAS  Google Scholar 

  13. Weaver, B. L. The origin of ocean island basalt end-member compositions: Trace element and isotopic constraints. Earth Planet. Sci. Lett. 104, 381–397 (1991)

    Article  ADS  CAS  Google Scholar 

  14. Farley, K. A., Natland, J. H. & Craig, H. Binary mixing of enriched and undegassed (primitive?) mantle components (He, Sr, Nd, Pb) in Samoan lavas. Earth Planet. Sci. Lett. 111, 183–199 (1992)

    Article  ADS  CAS  Google Scholar 

  15. Wright, E. & White, W. M. The origin of Samoa: new evidence from Sr, Nd and Pb isotopes. Earth Planet. Sci. Lett. 82, 151–162 (1987)

    Article  ADS  Google Scholar 

  16. Hauri, E. H., Shimizu, N., Dieu, J. & Hart, S. R. Evidence for hotspot-related carbonatite metasomatism in the oceanic upper mantle. Nature 365, 221–227 (1993)

    Article  ADS  CAS  Google Scholar 

  17. Rudnick, R. L. & Gao, S. in The Crust (ed. Rudnick, R. L.) 1–64, Vol. 3 of Treatise in Geochemistry (Elsevier, Amsterdam, 2003)

    Google Scholar 

  18. McDonough, W. F. Constraints on the composition of the continental lithospheric mantle. Earth Planet. Sci. Lett. 101, 1–18 (1990)

    Article  ADS  CAS  Google Scholar 

  19. Hart, S. R. et al. Genesis of the Western Samoa seamount province: age, geochemical fingerprint and tectonics. Earth Planet. Sci. Lett. 227, 37–56 (2004)

    Article  ADS  CAS  Google Scholar 

  20. Frey, F. A., Weis, D., Borisova, A. Y. & Xu, G. Involvement of continental crust in the formation of the Cretaceous Kerguelen plateau: new perspectives from ODP Let 120 sites. J. Petrol. 43, 1207–1239 (2002)

    Article  ADS  CAS  Google Scholar 

  21. Kamenetsky, V. S. et al. Remnants of Gondwanan continental lithosphere in oceanic upper mantle: evidence from the South Atlantic Ridge. Geology 29, 243–246 (2001)

    Article  ADS  CAS  Google Scholar 

  22. Bonatti, E. et al. Lower Cretaceous deposits trapped near the equatorial Mid-Atlantic Ridge. Nature 380, 518–520 (1996)

    Article  ADS  CAS  Google Scholar 

  23. Taylor, B. The single largest oceanic plateau: Ontong Java-Manihiki-Hikurangi. Earth Planet. Sci. Lett. 241, 372–380 (2006)

    Article  ADS  CAS  Google Scholar 

  24. Goldstein, S. J. & Jacobsen, S. B. Nd and Sr isotopic systematics of river water suspended material: implications for crustal evolution. Earth Planet. Sci. Lett. 87, 249–265 (1988)

    Article  ADS  CAS  Google Scholar 

  25. McCulloch, M. T. & Wasserburg, G. J. Sm-Nd and Rb-Sr chronology of continental crust formation. Science 200, 1003–1011 (1978)

    Article  ADS  CAS  Google Scholar 

  26. Hofmann, A. W. Mantle geochemistry: The message from oceanic volcanism. Nature 385, 219–229 (1997)

    Article  ADS  CAS  Google Scholar 

  27. McDonough, W. F. & Sun, S. S. The composition of the Earth. Chem. Geol. 120, 223–253 (1995)

    Article  ADS  CAS  Google Scholar 

  28. Su, Y. Global MORB Chemistry Compilation at the Segment Scale. Thesis, Columbia Univ. (2003)

  29. Hart, S. R. A large-scale isotope anomaly in the Southern Hemisphere mantle. Nature 309, 753–757 (1984)

    Article  ADS  CAS  Google Scholar 

  30. Hart, S. R. Heterogeneous mantle domains: signatures, genesis and mixing chronologies. Earth Planet. Sci. Lett. 90, 273–296 (1988)

    Article  ADS  CAS  Google Scholar 

  31. Koppers, A. A. P., Russell, J. A., Jackson, M. G., Konter, J., Staudigel, H. & Hart, S. R. Samoa reinstated as a primary hotspot trail. Geology (submitted)

Download references

Acknowledgements

We thank A. Hofmann and W. White for reviews. We thank N. Shimizu, R. Workman and R. Rudnick for discussions, and J. Natland for sharing unpublished data. This study was supported by National Science Foundation grants. We are grateful to the scientific party and ships crew of the R/V Kilo Moana for the success of the ALIA 2005 expedition (http://earthref.org/ERESE/projects/ALIA/).

Author Contributions M.G.J. performed most of the experimental work, developed the model and wrote the paper. S.R.H. and H.S. conceived the project, and were co-chiefs of the ALIA expedition. A.A.P.K. and J.K. were responsible for the cruise bathymetry, and A.A.P.K. greatly improved the figures. J.B. and M.K. provided analytical assistance and access to facilities. A.A.P.K., J.B., J.K. and J.A.R. helped with sample preparation. All authors participated in the discussion and interpretation of results, and commented on the manuscript.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Matthew G. Jackson.

Ethics declarations

Competing interests

Reprints and permissions information is available at www.nature.com/reprints. The authors declare no competing financial interests.

Supplementary information

Supplementary Information

The file contains a Supplementary Discussion that gives a model of the Samoan EM2 source, including calculations and assumptions. The file also contains a Supplementary Table 1 and a Supplementary Table 2 that together provide the model parameters used to calculate the depleted Ta’u and EM2 Samoan sources, respectively. The file also contains a Supplementary Table 3 that provides the new Samoan geochemical data. Three supplementary figures also are included in the file: Supplementary Figure 1 shows new helium isotope data from the remarkably enriched Samoan lavas; Supplementary Figure 2 is an expanded view of main text Figure 1, and shows the composition of the Samoan lavas in the context of individual samples from the upper continental crust; Supplementary Figure 3 compares the spidergram of a model melt of the EM2 source with the spidergram of an isotopically-enriched Samoan EM2 lava. (PDF 2886 kb)

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Jackson, M., Hart, S., Koppers, A. et al. The return of subducted continental crust in Samoan lavas. Nature 448, 684–687 (2007). https://doi.org/10.1038/nature06048

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nature06048

This article is cited by

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing