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.

  • Article
  • Published:

Ubiquitous ultra-depleted domains in Earth’s mantle

Abstract

Partial melting of Earth’s mantle generates oceanic crust and leaves behind a chemically depleted residual mantle. The time-integrated composition of this chemically depleted mantle is generally inferred from basalts produced at mid-ocean ridges. However, isotopic differences between oceanic mantle rocks and mid-ocean ridge basalts suggest that mantle and basalt composition could differ. Here we measure neodymium isotope ratios in olivine-hosted melt inclusions from lavas of the Azores mantle plume. We find neodymium isotope ratios that include the highest values measured in basalts, and suggest that melts from ultra-depleted mantle contribute to the isotopic diversity of the erupted lavas. Ultra-depleted melts have exceedingly low preservation potential during magma extraction and evolution due to progressive mixing with melts that are enriched in incompatible elements. A notable contribution of ultra-depleted melts to the Azores mantle plume therefore implies that variably depleted mantle is the volumetrically dominant component of the Azores plume. We argue that variably depleted mantle, sometimes ranging to ultra-depleted compositions, may be a ubiquitous part of most ocean island and mid-ocean ridge basalt sources. If so, Earth’s mantle may be more depleted than previously thought, which has important implications for the rate of mass exchange between crust and mantle, plume dynamics and compositional stratification of Earth’s mantle.

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

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Schematic diagram showing the melting area underneath mid-ocean ridges.
Fig. 2: 143Nd/144Nd of Azores melt inclusions compared to those of Azores and Mid-Atlantic ridge basalts and abyssal peridotites.
Fig. 3: Rare-earth element concentrations in melt inclusions and lavas.

Similar content being viewed by others

Data availability

The authors declare that the data supporting the findings of this study are available within the article and the Supplementary information.

References

  1. Hofmann, A. W. Chemical differentiation of the Earth—the relationship between mantle, continental-crust, and oceanic-crust. Earth Planet Sci. Lett. 90, 297–314 (1988).

    Article  Google Scholar 

  2. Gast, P. W., Tilton, G. R. & Hedge, C. Isotopic composition of lead and strontium from Ascension and Gough Islands. Science 145, 1181–1185 (1964).

    Article  Google Scholar 

  3. Allègre, C. J., Staudacher, T. & Sarda, P. Rare gas systematics: formation of the atmosphere, evolution and structure of the Earth’s mantle. Earth Planet Sci. Lett. 81, 127–150 (1987).

    Article  Google Scholar 

  4. Caro, G., Bourdon, B., Birck, J.-L. & Moorbath, S. High-precision 142Nd/144Nd measurements in terrestrial rocks: constraints on the early differentiation of the Earth’s mantle. Geochim. Cosmochim. Acta 70, 164–191 (2006).

    Article  Google Scholar 

  5. Bennett, V. C., Brandon, A. D. & Nutman, A. P. Coupled 142Nd-143Nd isotopic evidence for Hadean mantle dynamics. Science 318, 1907–1910 (2007).

    Article  Google Scholar 

  6. Stracke, A. in Encyclopedia of Marine Geosciences (eds Harff, J. et al.) 182–185 (Springer Netherlands, 2016).

  7. Langmuir, C. H., Klein, E. M. & Plank, T. in Mantle Flow and Melt Generation at Mid-Ocean Ridges (eds Morgan, J. P. et al.) 183–210 (AGU, 1992).

  8. Willbold, M. & Stracke, A. Trace element composition of mantle end-members: implications for recycling of oceanic and upper and lower continental crust. Geochem. Geophys. Geosys. 7, Q04004 (2006).

    Article  Google Scholar 

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

    Article  Google Scholar 

  10. Stracke, A. Earth’s heterogeneous mantle: a product of convection-driven interaction between crust and mantle. Chem. Geol. 330–331, 274–299 (2012).

    Article  Google Scholar 

  11. Stracke, A. in Encyclopedia of Geochemistry: A Comprehensive Reference Source on the Chemistry of the Earth (ed. White, W. M.) 867–878 (Springer International Publishing, 2018).

  12. Tackley, P. J. in Treatise on Geophysics (ed. Schubert, G.) 521–585 (Elsevier, 2015).

  13. Stracke, A. & Bourdon, B. The importance of melt extraction for tracing mantle heterogeneity. Geochim. Cosmochim. Acta 73, 218–238 (2009).

    Article  Google Scholar 

  14. Stracke, A. et al. Abyssal peridotite Hf isotopes identify extreme mantle depletion. Earth Planet Sci. Lett. 308, 359–368 (2011).

    Article  Google Scholar 

  15. Rudge, J. F., Maclennan, J. & Stracke, A. The geochemical consequences of mixing melts from a heterogeneous mantle. Geochim. Cosmochim. Acta 114, 112–143 (2013).

    Article  Google Scholar 

  16. Cipriani, A., Brueckner, H. K., Bonatti, E. & Brunelli, D. Oceanic crust generated by elusive parents: Sr and Nd isotopes in basalt-peridotite pairs from the Mid-Atlantic ridge. Geology 32, 657–660 (2004).

    Article  Google Scholar 

  17. Salters, V. J. M. & Dick, H. J. B. Mineralogy of the mid-ocean-ridge basalt source from neodymium isotopic composition of abyssal peridotites. Nature 418, 68–72 (2002).

    Article  Google Scholar 

  18. Salters, V. J. M., Mallick, S., Hart, S. R., Langmuir, C. H. & Stracke, A. Domains of depleted mantle; new evidence from hafnium and neodymium isotopes. Geochem. Geophys. Geosys. 12, Q10017 (2011).

    Google Scholar 

  19. Sanfilippo, A., Salters, V., Tribuzio, R. & Zanetti, A. Role of ancient, ultra-depleted mantle in mid-ocean-ridge magmatism. Earth Planet Sci. Lett. 511, 89–98 (2019).

    Article  Google Scholar 

  20. Liu, C.-Z., Snow, J. E., Brügmann, G., Hellebrand, E. & Hofmann, A. W. Non-chondritic HSE budget in Earth’s upper mantle evidenced by abyssal peridotites from Gakkel ridge (Arctic Ocean). Earth Planet Sci. Lett. 283, 122–132 (2009).

    Article  Google Scholar 

  21. Byerly, B. L. & Lassiter, J. C. Isotopically ultradepleted domains in the convecting upper mantle: implications for MORB petrogenesis. Geology 42, 203–206 (2014).

    Article  Google Scholar 

  22. Sobolev, A. V. & Shimizu, N. Ultra-depleted primary melt included in an olivine from the Mid-Atlantic ridge. Nature 363, 151–154 (1993).

    Article  Google Scholar 

  23. Sobolev, A. V., Hofmann, A. W., Jochum, K. P., Kuzmin, D. V. & Stoll, B. A young source for the Hawaiian plume. Nature 476, 434–437 (2011).

    Article  Google Scholar 

  24. Saal, A. E. et al. Pb isotopic variability in melt inclusions from the EMI-EMII-HIMU mantle end-members and the role of the oceanic lithosphere. Earth Planet Sci. Lett. 240, 605–620 (2005).

    Article  Google Scholar 

  25. Reinhard, A. A. et al. Sr and Nd isotopic compositions of individual olivine-hosted melt inclusions from Hawai’i and Samoa: implications for the origin of isotopic heterogeneity in melt inclusions from OIB lavas. Chem. Geol. 495, 36–49 (2018).

    Article  Google Scholar 

  26. Koornneef, J. M. et al. TIMS analysis of Sr and Nd isotopes in melt inclusions from Italian potassium-rich lavas using prototype 1013Ω amplifiers. Chem. Geol. 397, 14–23 (2015).

    Article  Google Scholar 

  27. Beier, C., Stracke, A. & Haase, K. M. The peculiar geochemical signatures of Sao Miguel (Azores) lavas: metasomatised or recycled mantle sources? Earth Planet Sci. Lett. 259, 186–199 (2007).

    Article  Google Scholar 

  28. Elliott, T., Blichert-Toft, J., Heumann, A., Koetsier, G. & Forjaz, V. The origin of enriched mantle beneath Sao Miguel, Azores. Geochim. Cosmochim. Acta 71, 219–240 (2007).

    Article  Google Scholar 

  29. Salters, V. J. M. & Zindler, A. Extreme Hf-176 Hf-177 in the sub-oceanic mantle. Earth Planet Sci. Lett. 129, 13–30 (1995).

    Article  Google Scholar 

  30. Bizimis, M., Griselin, M., Lassiter, J. C., Salters, V. J. M. & Sen, G. Ancient recycled mantle lithosphere in the Hawaiian plume: osmium-hafnium isotope evidence from peridotite mantle xenoliths. Earth Planet Sci. Lett. 257, 259–273 (2007).

    Article  Google Scholar 

  31. DeFelice, C., Mallick, S., Saal, A. E. & Huang, S. An isotopically depleted lower mantle component is intrinsic to the Hawaiian mantle plume. Nat. Geosci. 12, 487–492 (2019).

    Article  Google Scholar 

  32. Kumari, S., Paul, D. & Stracke, A. Open system models of isotopic evolution in Earth’s silicate reservoirs: implications for crustal growth and mantle heterogeneity. Geochim. Cosmochim. Acta 195, 142–157 (2016).

    Article  Google Scholar 

  33. French, S. W. & Romanowicz, B. Broad plumes rooted at the base of the Earth’s mantle beneath major hotspots. Nature 525, 95–99 (2015).

    Article  Google Scholar 

  34. Saki, M., Thomas, C., Nippress, S. E. J. & Lessing, S. Topography of upper mantle seismic discontinuities beneath the North Atlantic: the Azores, Canary and Cape Verde plumes. Earth Planet Sci. Lett. 409, 193–202 (2015).

    Article  Google Scholar 

  35. O’Neill, C. & Sigloch, K. in Volcanoes of the Azores: Revealing the Geological Secrets of the Central Northern Atlantic Islands (eds Kueppers, U. & Beier, C.) 71–87 (Springer Berlin Heidelberg, 2018).

  36. Montelli, R., Nolet, G., Dahlen, F. A. & Mastres, G. A catalogue of deep mantle plumes: new results from finite-frequency tomography. Geochem. Geophys. Geosys. 7, Q11007 (2006).

    Article  Google Scholar 

  37. Montelli, R. et al. Finite-frequency tomography reveals a variety of plumes in the mantle. Science 303, 338–343 (2004).

    Article  Google Scholar 

  38. Maguire, R., Ritsema, J. & Goes, S. Signals of 660 km topography and harzburgite enrichment in seismic images of whole-mantle upwellings. Geophys. Res. Lett. 44, 3600–3607 (2017).

    Article  Google Scholar 

  39. Wolfe, C. J. et al. Mantle shear-wave velocity structure beneath the Hawaiian hot spot. Science 326, 1388–1390 (2009).

    Article  Google Scholar 

  40. Huang, J. & Davies, G. F. Geochemical processing in a three-dimensional regional spherical shell model of mantle convection. Geochem. Geophys. Geosys. 8, Q11006 (2007).

    Google Scholar 

  41. Schutt, D. L. & Lesher, C. E. Effects of melt depletion on the density and seismic velocity of garnet and spinel lherzolite. J. Geophys. Res.: Solid Earth 111, B05401 (2006).

    Article  Google Scholar 

  42. Nakagawa, T., Tackley, P. J., Deschamps, F. & Connolly, J. A. D. The influence of MORB and harzburgite composition on thermo-chemical mantle convection in a 3-D spherical shell with self-consistently calculated mineral physics. Earth Planet Sci. Lett. 296, 403–412 (2010).

    Article  Google Scholar 

  43. Ishii, T., Kojitani, H. & Akaogi, M. Phase relations of harzburgite and MORB up to the uppermost lower mantle conditions: precise comparison with pyrolite by multisample cell high-pressure experiments with implication to dynamics of subducted slabs. J. Geophys. Res. Solid Earth 124, 3491–3507 (2019).

    Article  Google Scholar 

  44. Irifune, T. & Ringwood, A. E. Phase transformations in subducted oceanic crust and buoyancy relationships at depths of 600–800 km in the mantle. Earth Planet Sci. Lett. 117, 101–110 (1993).

    Article  Google Scholar 

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

    Article  Google Scholar 

  46. Herzberg, C. & Asimow, P. D. Petrology of some oceanic island basalts: PRIMELTS2.XLS software for primary magma calculation. Geochem. Geophys. Geosys. 9, Q09001 (2008).

    Article  Google Scholar 

  47. Beier, C., Haase, K. M. & Turner, S. P. Conditions of melting beneath the Azores. Lithos 144–145, 1–11 (2012).

    Article  Google Scholar 

  48. Ribe, N. M. The dynamics of plume ridge interaction, 2: off-ridge plumes. J. Geophys. Res. 101, 19,195–116,204 (1996).

    Article  Google Scholar 

  49. Brandenburg, J. P. & van Keken, P. E. Deep storage of oceanic crust in a vigorously convecting mantle. J. Geophys. Res. Solid Earth 112, B06403 (2007).

    Article  Google Scholar 

  50. Mallick, S., Dick, H. J. B., Sachi-Kocher, A. & Salters, V. J. M. Isotope and trace element insights into heterogeneity of subridge mantle. Geochem. Geophys. Geosys. 15, 2438–2453 (2014).

    Article  Google Scholar 

  51. Snow, J. E., Hart, S. R. & Dick, H. J. B. Nd and Sr isotope evidence linking mid-ocean-ridge basalts and abyssal peridotites. Nature 371, 57–60 (1994).

    Article  Google Scholar 

  52. Warren, J. M., Shimizu, N., Sakaguchi, C., Dick, H. J. B. & Nakamura, E. An assessment of upper mantle heterogeneity based on abyssal peridotite isotopic compositions. J. Geophys. Res. 114, B12203 (2009).

    Article  Google Scholar 

  53. Mallick, S., Standish, J. J. & Bizimis, M. Constraints on the mantle mineralogy of an ultra-slow ridge: hafnium isotopes in abyssal peridotites and basalts from the 9–25°E Southwest Indian ridge. Earth Planet Sci. Lett. 410, 42–53 (2015).

    Article  Google Scholar 

  54. Brunelli, D., Cipriani, A. & Bonatti, E. Thermal effects of pyroxenites on mantle melting below mid-ocean ridges. Nat. Geosci. 11, 520–525 (2018).

    Article  Google Scholar 

  55. Genske, F. S. et al. Comparing the nature of the western and eastern Azores mantle. Geochim. Cosmochim. Acta 172, 76–92 (2016).

    Article  Google Scholar 

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

    Article  Google Scholar 

  57. Jarosewich, E., Nelen, J. A. & Norberg, J. A. Reference samples for electron microprobe analysis. Geostand. Newsl. 4, 43–47 (1980).

    Article  Google Scholar 

  58. Van Achterberg, E., Ryan, C., Jackson, S. & Griffin, W. in Appendix 3: LASER-Ablation-ICPMS in the Earth Sciences, Vol. 29 (ed Sylvester, P.) 239–243 (Mineralogical Association of Canada, 2001).

  59. Griffin, W. L., Powell, W. J., Pearson, N. J. & O’Reilly, S. Y. in Laser Ablation–ICP–MS in the Earth Sciences: Current Practices and Outstanding Issues, Vol. 40 (ed Sylvester, P.) 307–311 (Mineralogical Association of Canada, 2008).

  60. Jochum, K. P. et al. GeoReM: a new geochemical database for reference materials and isotopic standards. Geostand. Geoanal. Res. 29, 333–338 (2005).

    Article  Google Scholar 

  61. Hart, S. R. & Brooks, C. The geochemistry and evolution of the early Precambrian mantle. Contrib. Miner. Pet. 61, 109–128 (1977).

    Article  Google Scholar 

  62. Pin, C. & Zalduegui, J. F. S. Sequential separation of light rare-earth elements, thorium and uranium by miniaturized extraction chromatography: application to isotopic analyses of silicate rocks. Anal. Chim. Acta 339, 79–89 (1997).

    Article  Google Scholar 

  63. Koornneef, J. M., Bouman, C., Schwieters, J. B. & Davies, G. R. Measurement of small ion beams by thermal ionisation mass spectrometry using new 1013Ohm resistors. Anal. Chim. Acta 819, 49–55 (2014).

    Article  Google Scholar 

Download references

Acknowledgements

This work was supported by the German Research Foundation (grant no. GE2817/6-1). F.G. acknowledges support from Europlanet 2020 RI, which has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement no. 65420. J.M.K. received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme under grant agreement no. 759563. C. Beier is thanked for contributing samples from Pico Island.

Author information

Authors and Affiliations

Authors

Contributions

A.S. and F.G. conceived and designed the study. A.S., F.G. and J.M.K. wrote the manuscript and contributed to data interpretation. F.G. and J.B. conducted the electron microprobe and LA-ICPMS analyses. F.G. and A.S. conducted the MC-ICPMS analyses. F.G. and J.M.K. conducted the TIMS analyses.

Corresponding author

Correspondence to Andreas Stracke.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Stracke, A., Genske, F., Berndt, J. et al. Ubiquitous ultra-depleted domains in Earth’s mantle. Nat. Geosci. 12, 851–855 (2019). https://doi.org/10.1038/s41561-019-0446-z

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41561-019-0446-z

This article is cited by

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