Letter | Published:

Three generations of diamonds from old continental mantle

Naturevolume 366pages256258 (1993) | Download Citation

Subjects

Abstract

INCLUSION-BEARING diamonds erupted by kimberlites are time capsules from the sub-continental mantle. Diamonds with peridotitic mineral inclusions ('peridotitic diamonds') from Cretaceous kimberlites in southern Africa have resided in stable mantle beneath the Kaapvaal craton since the Archaean1. Diamonds with eclogitic inclusions ('eclogitic diamonds') reflect episodic mantle events during the Proterozoic2–3. Here we discuss and present isotope data for a further category of diamonds from the Proterozoic Premier kimberlite, in which peridotitic inclusion minerals have compositions reflecting an origin in both harzburgitic (clinopyroxene-free) and Iherzolitic (clinopyroxene-bearing) assemblages. The harzburgitic garnet inclusions and their counterparts found as isolated minerals ('macrocrysts') in the kimberlite host rock4 have neodym-ium and strontium isotope signatures consistent with an Archaean age (>3,000 Myr) and metasomatized mantle source. Lherzolitic garnet and clinopyroxene inclusions yield a preferred Sm-Nd isochron age of 1,930 Myr, which is 100 Myr less than that of the adjacent Bushveld Complex5, suggesting a link analogous to that between harzburgitic diamond formation and komatiitic magma tism in the Archaean1. The final generation of diamonds, those with eclogitic inclusions, were formed 1,150 Myr ago, just before kimberlite emplacement6.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

References

  1. 1

    Richardson, S. H., Gurney, J. J., Erlank, A. J. & Harris, J. W. Nature 310, 198–202 (1984).

  2. 2

    Richardson, S. H., Erlank, A. J., Harris, J. W. & Hart, S. R. Nature 346, 54–56 (1990).

  3. 3

    Smith, C. B. et al. Geochim, cosmochim. Acta 55, 2579–2590 (1991).

  4. 4

    Gurney, J. J. & Switzer, G. S. Contr. Miner. Petrol. 39, 103–116 (1973).

  5. 5

    Hamilton, J. J. Petrol. 18, 24–52 (1977).

  6. 6

    Richardson, S. H. Nature 322, 623–626 (1986).

  7. 7

    de Wit, M. J. et al. Nature 357, 553–562 (1992).

  8. 8

    Smith, C. B. thesis, Univ. Witwatersrand (1983).

  9. 9

    Jones, R. A. thesis, Univ. Leeds (1984).

  10. 10

    Burgess, R., Turner, G., Laurenzi, M. & Harris, J. W. Earth planet. Sci. Lett. 94, 22–28 (1989).

  11. 11

    Phillips, D., Onstott, T. C. & Harris, J. W. Nature 340, 460–462 (1989).

  12. 12

    Allsopp, H. L. Burger, A. J. & van Zyl, C. Earth planet. Sci. Lett. 3, 161–166 (1967).

  13. 13

    Eales, H. V. et al. J. Afr. Earth Sci. 16, 121–142 (1993).

  14. 14

    Gurney, J. J., Harris, J. W., Rickard, R. S. & Moore, R. O. Trans. geol. Soc. S. Afr. 88, 301–310 (1985).

  15. 15

    Deines, P., Harris, J. W., Spear, P. M. & Gurney, J. J. Geochim. cosmochim. Acta 53, 1367–1378 (1989).

  16. 16

    Shimizu, N. & Richardson, S. H. Geochim. cosmochim. Acta 51, 755–758 (1987).

  17. 17

    Richardson, S. H. in Continental Mantle (ed. Menzies, M. A.) 55–65 (Clarendon, Oxford, 1990).

  18. 18

    Walraven, F., Armstrong, R. A. & Kruger, F. J. Tectonophysics 171, 23–48 (1990).

  19. 19

    Wasserburg, G. J., Jacobsen, S. B., DePaolo, D. J., McCulloch, M. T. & Wen, T. Geochim. cosmochim. Acta 45, 2311–2323 (1981).

Download references

Author information

Affiliations

  1. Department of Geological Sciences, University of Cape Town, Rondebosch, 7700, South Africa

    • S. H. Richardson
    •  & J. J Gurney
  2. Department of Geology and Applied Geology, University of Glasgow, Glasgow, G12 8QQ, UK

    • J. W. Harris

Authors

  1. Search for S. H. Richardson in:

  2. Search for J. W. Harris in:

  3. Search for J. J Gurney in:

About this article

Publication history

Received

Accepted

Issue Date

DOI

https://doi.org/10.1038/366256a0

Further reading

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.