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:

Copper enrichment in arc magmas controlled by overriding plate thickness

Nature Geoscience volume 7, pages 43–46 (2014)Cite this article

Subjects

Abstract

Porphyry copper systems supply about 75% of the world’s copper1. They form above subduction zones and are preferentially associated with calc-alkaline magmas1,2. Such magmas result from continuous iron depletion during differentiation, in contrast to tholeiitic magmas that show initial iron enrichment during differentiation3. The formation of calc-alkaline magmas is favoured by high water content and oxygen fugacity4,5,6,7. These characteristics, as well as magmatic metal contents, are thought to be imparted in the mantle source by fluids of the subducted slab8,9,10. Yet this process does not explain why porphyry copper systems preferentially occur in thicker arcs1,2. Here I present a statistical assessment of more than 40,000 published geochemical analyses of magmatic rocks from 23 Quaternary-aged volcanic arcs worldwide. I find that magmas of thicker arcs are systematically more calc-alkaline and more depleted in copper than magmas of thinner arcs. This implies that the missing copper in the former accumulates as copper sulphides within or at the base of thicker arcs. Such copper accumulations are an essential step in forming porphyry systems11,12,13. These results suggest that the thickness of the overriding plate provides a more important control on magma differentiation than the composition of the mantle source, and can explain the preferential association of porphyry copper systems with calc-alkaline magmas and thicker arcs.

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

Access options

Buy this article

  • Purchase on Springer Link
  • Instant access to full article PDF
Buy now

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

Figure 1: Plots of Cu and Fe2O3tot versus MgO for magmatic rocks of 23 Quaternary arcs.
Figure 2: Correlations between crustal thickness, Cu and Fe2O3tot in 23 Quaternary arc magmas.

Similar content being viewed by others

References

  1. Sillitoe, R. H. Porphyry copper systems. Econ. Geol. 105, 3–41 (2010).

    Article  Google Scholar 

  2. Cooke, D., Hollings, P. & Walshe, J. L. Giant porphyry deposits: Characteristics, distribution, and tectonic controls. Econ. Geol. 100, 801–818 (2005).

    Article  Google Scholar 

  3. Miyashiro, A. Volcanic rock series in island arcs and active continental margins. Am. J. Sci. 274, 321–355 (1974).

    Article  Google Scholar 

  4. Zimmer, M. M. et al. The role of water in generating the calc-alkaline trend: New volatile data for Aleutian magmas and a new Tholeiitic Index. J. Petrol. 51, 2411–2444 (2010).

    Article  Google Scholar 

  5. Berndt, J., Koepke, J. & Holtz, F. An experimental investigation of the influence of water and oxygen fugacity on differentiation of MORB at 200 MPa. J. Petrol. 46, 135–167 (2005).

    Article  Google Scholar 

  6. Sisson, T. W. & Grove, T. L. Experimental investigations of the role of H2O in calc-alkaline differentiation and subduction zone magmatism. Contrib. Mineral. Petrol. 113, 143–166 (1993).

    Article  Google Scholar 

  7. Osborn, E. F. Role of oxygen partial pressure in the crystallization and differentiation of basaltic magma. Am. J. Sci. 257, 609–647 (1959).

    Article  Google Scholar 

  8. Mungall, J. E. Roasting the mantle: Slab melting and the genesis of major Au and Au-rich Cu deposits. Geology 30, 915–918 (2002).

    Article  Google Scholar 

  9. Gill, J. B. Orogenic Andesites and Plate Tectonics (Springer, 1981).

    Book  Google Scholar 

  10. Kelley, K. A. & Cottrell, E. Water and the oxidation state of subduction zone magmas. Science 325, 605–607 (2009).

    Article  Google Scholar 

  11. Lee, C-T.A. et al. Copper systematics in arc magmas and implications for crust–mantle differentiation. Science 336, 64–68 (2012).

    Article  Google Scholar 

  12. Sillitoe, R. H. Copper provinces. SEG Spec. Pub. 16, 1–18 (2012).

    Google Scholar 

  13. Shafiei, B., Haschke, M. & Shahabpour, J. Recycling of orogenic arc crust triggers porphyry Cu mineralization in Kerman Cenozoic arc rocks, southeastern Iran. Miner. Deposita 44, 265–283 (2009).

    Article  Google Scholar 

  14. Lee, C-T. A. et al. The redox state of arc mantle using Zn/Fe systematics. Nature 468, 681–685 (2010).

    Article  Google Scholar 

  15. Dauphas, N. et al. Iron isotopes may reveal the redox conditions of mantle melting from Archean to present. Earth Planet. Sci. Lett. 288, 255–267 (2009).

    Article  Google Scholar 

  16. Coulon, C. & Thorpe, R. S. Role of continental crust in petrogenesis of orogenic volcanic associations. Tectonophysics 77, 79–93 (1981).

    Article  Google Scholar 

  17. Lee, C-T. A., Lee, T. C. & Wu, C-T. Modeling the compositional evolution of recharging, evacuating, and fractionating (REFC) magma chambers: Implications for differentiation of arc magmas. Geochim. Cosmochim. Acta http://dx.doi.org/10.1016/j.gca.2013.08.009 (2013).

  18. Kelley, K. A., Cottrell, E. & Brounce, M. N. The relationship between f O2 and calc-alkaline affinity of arc magmas. Mineral. Mag. 77, 1446 (2013).

    Google Scholar 

  19. Chaussard, E. & Amelung, F. Precursory inflation of shallow magma reservoirs at west Sunda volcanoes detected by InSAR. Geophys. Res. Lett. 39, L21311 (2012).

    Article  Google Scholar 

  20. Annen, C., Blundy, J. D & Sparks, R. S. J. The genesis of intermediate and silicic magmas in deep crustal hot zones. J. Petrol. 47, 505–539 (2006).

    Article  Google Scholar 

  21. Ghiorso, M. S. & Sack, R. O. Chemical mass transfer in magmatic processes. IV. A revised and internally consistent thermodynamic model for the interpolation and extrapolation of liquid–solid equilibria in magmatic systems at elevated temperatures and pressures. Contrib. Mineral. Petrol. 119, 197–212 (1995).

    Article  Google Scholar 

  22. Asimow, P. D. & Ghiorso, M. S. Algorithmic modifications extending MELTS to calculate subsolidus phase relations. Am. Mineral. 83, 1127–1131 (1998).

    Article  Google Scholar 

  23. Jenner, F. E., O’Neill, H. St. C., Arculus, R. J. & Mavrogenes, J. A. The magnetite crisis in the evolution of arc-related magmas and the initial concentration of Au, Ag and Cu. J. Petrol. 51, 2445–2464 (2010).

    Article  Google Scholar 

  24. Sun, W., Arculus, R. J., Kamenetski, V. S. & Binns, R. A. Release of gold-bearing fluids in convergent margin magmas prompted by magnetite crystallization. Nature 431, 975–978 (2004).

    Article  Google Scholar 

  25. Nadeau, O., Williams-Jones, A. E. & Stix, J. Sulphide magma as a source of metals in arc-related magmatic hydrothermal ore fluids. Nature Geosci. 3, 501–505 (2010).

    Article  Google Scholar 

  26. Chiaradia, M., Ulianov, A., Kouzmanov, K. & Beate, B. Why large porphyry Cu deposits like high Sr/Y magmas? Sci. Rep. 2, 685 (2012).

    Article  Google Scholar 

  27. Clark, A. H. Are outsize porphyry copper deposits either anatomically or environmentally distinctive? SEG Spec. Pub. 2, 213–284 (1995).

    Google Scholar 

  28. Tosdal, R. M. & Richards, J. P. Magmatic and structural controls on the development of porphyry Cu±Mo±Au deposits. Rev. Econom. Geol. 14, 157–181 (2001).

    Google Scholar 

  29. Zellmer, G. Some first-order observations on magma transfer from mantle wedge to upper crust at volcanic arcs. Geol. Soc. Lond. Spec. Publ. 304, 15–31 (2008).

    Article  Google Scholar 

Download references

Acknowledgements

A review by C-T. A. Lee (Rice University) contributed to significantly improve an earlier version of this work. This study was financially supported by the Swiss National Science Foundation (Project no. 200020_137663).

Author information

Authors and Affiliations

  1. Department of Earth Sciences, University of Geneva, Rue des Maraîchers 13, Geneva 1205, Switzerland

    Massimo Chiaradia

Authors
  1. Massimo Chiaradia
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Massimo Chiaradia.

Ethics declarations

Competing interests

The author declares no competing financial interests.

Supplementary information

Supplementary Information

Supplementary Information (PDF 1320 kb)

Rights and permissions

Reprints and permissions

About this article

Cite this article

Chiaradia, M. Copper enrichment in arc magmas controlled by overriding plate thickness. Nature Geosci 7, 43–46 (2014). https://doi.org/10.1038/ngeo2028

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/ngeo2028

This article is cited by

Search

Advanced 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