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Porphyry copper deposit formation by sub-volcanic sulphur dioxide flux and chemisorption


Porphyry copper deposits—the primary source of the world’s copper—are a consequence of the degassing of intrusion complexes in magmatic arcs associated with ancient subduction zones1,2. They are characterized by copper and iron sulphides, commonly found with anhydrite (CaSO4), over scales of several kilometres through intensely altered and fractured rocks1. The magmatic source of the metals is broadly understood, but the processes that transport and deposit the metals at the megaton scale are unclear. The hydrogen sulphide necessary for metal deposition is commonly assumed to form by a reaction between sulphur dioxide and water, but this reaction is inefficient3 and cannot explain the formation of economic-grade deposits. Here we use high-temperature laboratory experiments to show that a very rapid chemisorption reaction occurs between sulphur dioxide gas, a principal component of magmatic gas mixtures, and calcic feldspar, an abundant mineral in the arc crust. The chemisorption reaction generates the mineral anhydrite and hydrogen sulphide gas, and triggers deposition of metal sulphides. We use thermodynamic calculations to show that as magmatic gas cools and expands the concentration of hydrogen sulphide gas increases exponentially to drive efficient deposition of metal sulphides and consequent formation of economic-grade porphyry copper deposits.

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Figure 1: Features and formation environments of porphyry copper deposits.
Figure 2: FE-SEM images of reacted materials.
Figure 3: SO2 chemisorption products and process.
Figure 4: Thermodynamic properties and H2S(g)/SO2(g) of expanding sub-volcanic gases.

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

    Article  Google Scholar 

  2. Richards, J. P. Postsubduction porphyry Cu–Au and epithermal Au deposits: Products of remelting of subduction-modified lithosphere. Geology 37, 247–250 (2009).

    Article  Google Scholar 

  3. Giggenbach, W. F. Redox processes governing the chemistry of fumarolic gas discharges from White Island, New Zealand. Appl. Geochem. 2, 143–161 (1987).

    Article  Google Scholar 

  4. Singer, D. A., Berger, V. I. & Moring, B. C. Porphyry Copper Deposits of the World: Database, Maps, and Preliminary Analysis (US Department of the Interior, US Geological Survey, 2008).

    Google Scholar 

  5. Landtwing, M. R. et al. The Bingham Canyon porphyry Cu–Mo–Au deposit. III. Zoned copper–gold ore deposition by magmatic vapor expansion. Econ. Geol. 105, 91–118 (2010).

    Article  Google Scholar 

  6. Henley, R. W. & McNabb, A. Magmatic vapor plumes and ground-water interaction in porphyry copper emplacement. Econ. Geol. 73, 1–20 (1978).

    Article  Google Scholar 

  7. Weis, P., Dreisner, T. & Heinrich, C. A. Porphyry-copper ore shells form at stable pressure–temperature fronts within dynamic fluid plumes. Science 338, 1613–1616 (2012).

    Article  Google Scholar 

  8. Oppenheimer, C., Fischer, T. P. & Scaillet, B. in Treatise on Geochemistry 2nd edn (eds Holland, H. D. & Turekian, K. K.) 111–179 (Elsevier, 2014).

    Book  Google Scholar 

  9. 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 

  10. Henley, R. W. & Berger, B. R. Nature’s refineries—Metals and metalloids in arc volcanoes. Earth-Sci. Rev. 125, 146–170 (2013).

    Article  Google Scholar 

  11. Wilkinson, J. J. Triggers for the formation of porphyry ore deposits in magmatic arcs. Nature Geosci. 6, 917–925 (2013).

    Article  Google Scholar 

  12. Gustafson, L. B. & Hunt, J. P. The porphyry copper deposit at El Salvador, Chile. Econ. Geol. 70, 857–912 (1975).

    Article  Google Scholar 

  13. Cooke, D. R., Hollings, P., Wilkinson, J. J. & Tosdal, R. M. in Treatise on Geochemistry 2nd edn (eds Holland, H. D. & Turekian, K. K.) 357–381 (Elsevier, 2014).

    Book  Google Scholar 

  14. Sillitoe, R. H. Economic Geology One Hundredth Anniversary Volume 724–768 (Society of Economic Geologists, 2005).

    Google Scholar 

  15. Dickson, F. W., Blount, C. W. & Tunell, G. Use of hydrothermal solution equipment to determine the solubility of anhydrite in water from 100 °C to 275 °C and from 1 bar to 1000 bars pressure. Am. J. Sci. 261, 61–78 (1963).

    Article  Google Scholar 

  16. Burnham, C. W. in Geochemistry of Hydrothermal Ore Deposits (ed. Barnes, H. L.) 71–136 (John Wiley, 1979).

    Google Scholar 

  17. Li, E. Y., Chareev, D. A., Shilobreeva, S. N., Grichuk, D. V. & Tyutyunnik, O. A. Experimental study of sulfur dioxide interaction with silicates and aluminosilicates at temperatures of 650 and 850 °C. Geochem. Int. 48, 1039–1046 (2010).

    Article  Google Scholar 

  18. Fegley, B. & Prinn, R. G. Estimation of the rate of volcanism on Venus from reaction rate measurements. Nature 337, 55–58 (1989).

    Article  Google Scholar 

  19. Ayris, P. M. et al. SO2 sequestration in large volcanic eruptions: High-temperature scavenging by tephra. Geochim. Cosmochim. Acta 110, 58–69 (2013).

    Article  Google Scholar 

  20. Lee, R. J., King, P. L. & Ramsey, M. S. Spectral analysis of synthetic quartzofeldspathic glasses using laboratory thermal infrared spectroscopy. J. Geophys. Res. 115, B06202 (2010).

    Article  Google Scholar 

  21. Ohmoto, H. & Goldhaber, M. B. Geochemistry of Hydrothermal Ore Deposits 517–612 (John Wiley, 1997).

    Google Scholar 

  22. Kesler, S. E., Chryssoulis, S. L. & Simon, G. Gold in porphyry copper deposits: Its abundance and fate. Ore Geol. Rev. 21, 103–124 (2002).

    Article  Google Scholar 

  23. Bodnar, R. J., Lecumberri-Sanchez, P., Moncada, D. & Steele-MacInnis, M. in Treatise on Geochemistry 2nd edn (eds Holland, H. D. & Turekian, K. K.) 119–142 (Elsevier, 2014).

    Book  Google Scholar 

  24. Chambefort, I., Dilles, J. H. & Kent, A. J. R. Anhydrite-bearing andesite and dacite as a source for sulfur in magmatic-hydrothermal mineral deposits. Geology 36, 719–722 (2008).

    Article  Google Scholar 

  25. Mastin, L. G. & Ghiorso, M. S. Adiabatic temperature changes of magma–gas mixtures during ascent and eruption. Contrib. Mineral. Petrol. 141, 307–321 (2001).

    Article  Google Scholar 

  26. Migdisov, A. A., Bychkov, A. Y., Williams-Jones, A. E. & van Hinsberg, V. J. A predictive model for the transport of copper by HCl-bearing water vapour in ore-forming magmatic-hydrothermal systems: Implications for copper porphyry ore formation. Geochim. Cosmochim. Acta 129, 33–53 (2014).

    Article  Google Scholar 

  27. Audétat, A. & Pettke, T. Evolution of a porphyry-Cu mineralized magma system at Santa Rita, New Mexico (USA). J. Petrol. 47, 2021–2046 (2006).

    Article  Google Scholar 

  28. Herve, M. et al. in Geology and Genesis of Major Copper Deposits and Districts of the World (eds Hedenquist, J. W., Harris, M. & Camus, F.) 55–78 (Society of Economic Geologists, 2012).

    Google Scholar 

  29. Meinert, L. D., Hefton, K. K., Mayes, D. & Tasiran, I. Geology, zonation, and fluid evolution of the Big Gossan Cu–Au skarn deposit, Ertsberg District, Irian Jaya. Econ. Geol. 92, 509–534 (1997).

    Article  Google Scholar 

  30. Carroll, M. R. & Wyllie, P. J. Experimental phase relations in the system tonalite-peridotite-H2O at 15 kb; implications for assimilation and differentiation processes near the crust–mantle boundary. J. Petrol. 30, 1351–1382 (1989).

    Article  Google Scholar 

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This investigation was triggered by interactions with P. Delmelle and P. Ayris in relation to the reactivity of volcanic ashes. We thank R. Arculus, M. Goldhaber, R. King, R. Sillitoe, H. O’Neill, A. Putnis, J. Ward and T. Whan for valuable discussions. We also wish to acknowledge the foundations of porphyry copper analysis laid by L. Gustafson. We thank N. Bishop, D. Olson and K. Schroeder of Kennecott Exploration (Rio Tinto) for confirmation of the occurrence of anhydrite in deep drilling at Bingham Canyon, Utah. K. Friehauf very kindly provided the photograph of the Grasberg porphyry copper deposit for Fig. 1a. Graphic enhancement was provided by D. Henley, and D. Hill kindly provided his original cartoon for a generic volcano that we have used in Fig. 1c. Constructive comments on earlier versions of this work were received from J. Dilles and R. Herrington. Funding was provided by an Australian Research Council Future Fellowship to P.L.K. R.W.H. and P.L.K. wish to dedicate this paper to the late W. S. Fyfe, one of the founders of modern geochemistry, and a lifetime friend and mentor.

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R.W.H. conceived the initial concept. All authors collaborated in the analysis and interpretation and the growth of the concept.

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Correspondence to Richard W. Henley, Penelope L. King or Jeremy L. Wykes.

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The authors declare no competing financial interests.

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Henley, R., King, P., Wykes, J. et al. Porphyry copper deposit formation by sub-volcanic sulphur dioxide flux and chemisorption. Nature Geosci 8, 210–215 (2015).

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