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.

  • Letter
  • Published:

Significance of Strontium Isotope Ratios in Theories of Carbonatite Genesis

Abstract

RECENTLY, several investigators1–3 have compared the 87Sr/86Sr ratios of carbonate rocks from carbonatite complexes with those of sedimentary limestones. Powell et al.1 quote a mean value of 0.7035 for carbonatites while limestones are usually greater than 0.7090. All results are normalized to 86Sr/88Sr = 0.1194 and relative to a value of 0.7085 for normalized 87Sr/86Sr on the Eimer and Amend standard SrCO3. Hamilton and Deans reported a mean 87Sr/86Sr ratio of 0.7060 for nine carbonatites. Powell et al. concluded that the difference in 87Sr/86Sr values demonstrates that carbonatites are not mobilized limestones. For this criterion to be effective, however, two requirements must be fulfilled: (a) there must be a negligible overlap of the strontium isotope ratios of carbonatites and limestones and (b) the 87Sr/86Sr ratios of limestones must not be altered by metamorphism. Powell et al.1 showed that a xenolith of Trenton limestone (Ordovician) from the Mount Royal gabbro (Montreal) has essentially the same 87Sr/86Sr ratio as the Trenton limestone at some distance from the intrusion. From these measurements, they inferred that requirement (b) is generally satisfied. It seems to us, however, that the behaviour of a small xenolith that has merely been recrystallized but not otherwise reacted on by the enclosing magma cannot readily be extrapolated to cover the case of a large mass of limestone that might be melted and intimately incorporated in a magma with extensive reaction.

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

Access options

Rent or buy this article

Prices vary by article type

from$1.95

to$39.95

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

Similar content being viewed by others

References

  1. Powell, J. L., Hurley, P. M., and Fairbairn, H. W., Nature, 196, 1085 (1962).

    Article  ADS  CAS  Google Scholar 

  2. Hamilton, E. I., and Deans, T., Nature, 198, 776 (1963).

    Article  ADS  CAS  Google Scholar 

  3. Powell, J. L., Proc. Intern. Min. Assoc., India, 1964 (in the press).

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

HAYATSU, A., YORK, D., FARQUHAR, R. et al. Significance of Strontium Isotope Ratios in Theories of Carbonatite Genesis. Nature 207, 625–626 (1965). https://doi.org/10.1038/207625a0

Download citation

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/207625a0

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