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Gold concentrations of magmatic brines and the metal budget of porphyry copper deposits

Nature volume 399, pages 676–679 (1999)Cite this article

Abstract

Porphyry copper–molybdenum–gold deposits are the most important metal resources formed by hydrothermal processes associated with magmatism. It remains controversial, however, whether the metal content of porphyry-style and other magmatic–hydrothermal deposits is dominantly controlled by metal partitioning between magma and an exsolving magmatic fluid phase1,2 or by scavenging of metals from solid upper-crustal rocks by surface-derived fluids3. It also remains unknown to what degree the metal content in such deposits is affected by selective mineral precipitation from the ore fluid. Extremely saline fluids4, precipitating quartz and ore minerals in veins have been inferred to have a significant magma-derived component, on the basis of geological5, isotopic6,7 and experimental evidence8,9. Here we report gold and copper concentrations of single fluid inclusions in quartz, determined by laser-ablation inductively coupled plasma mass spectrometry. The results show that the Au/Cu ratio of primary high-temperature brines is identical to the bulk Au/Cu ratio in two of the world's largest copper–gold ore bodies. This indicates that the bulk metal budget of such deposits is primarily controlled by the composition of the incoming fluid, which is, in turn, likely to be controlled by the crystallization process in an underlying magma chamber.

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Figure 1: Photomicrographs of a polished section of ore and of a polyphase brine inclusion.
Figure 2: Transient laser ablation ICP-MS signal and Au versus Cu plots from Grasberg and Bajo de la Alumbrera.

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References

  1. Candela, P. A. Rev. Econ. Geol. 4, 203–221 (1989).

    Google Scholar 

  2. Cline, J. S. & Bodnar, R. J. Can economic porphyry copper mineralization be generated by a typical calc-alkaline melt? J. Geophys. Res. 96, 8113–8126 (1991).

    Article  ADS  CAS  Google Scholar 

  3. Sheets, R. W., Nesbitt, B. E. & Muehlenbachs, K. Meteoric water component in magmatic fluids from porphyry copper mineralization, Babine Lake area, British Columbia. Geology 24, 1091–1094 (1996).

    Article  ADS  CAS  Google Scholar 

  4. Roedder, E. Fluid Inclusions(Mineralogical Soc. of America, 1984).

    Book  Google Scholar 

  5. Hedenquist, J. W. & Lowenstern, J. B. The role of magmas in the formation of hydrothermal ore deposits. Nature 370, 519–527 (1994).

    Article  ADS  CAS  Google Scholar 

  6. Sheppard, S. M. F., Nielsen, R. L. & Taylor, H. P. J. Hydrogen and oxygen isotope ratios in minerals from porphyry copper deposits. Econ. Geol. 66, 515–542 (1971).

    Article  CAS  Google Scholar 

  7. Sheppard, S. M. F., Nielson, R. L. & Taylor, H. P. J. Oxygen and hydrogen ratios of clay minerals from porphyry copper deposits. Econ. Geol. 64, 755–777 (1969).

    Article  CAS  Google Scholar 

  8. Hemley, J. J., Cygan, G. L., Fein, J. B., Robinson, G. R. & D'Angelo, W. M. Hydrothermal ore-forming processes in the light of studies in rock-buffered systems: I. Iron-copper-zinc-lead sulfide solubility relations. Econ. Geol. 87, 1–22 (1992).

    Article  CAS  Google Scholar 

  9. Seward, T. M. & Barnes, H. L. in Geochemistry of Hydrothermal Ore Deposits3rd edn (ed. Barnes, H. L.) 435–486 (Wiley, New York, 1997).

    Google Scholar 

  10. Taylor, S. R. & McLennan, S. M. The Continental Crust: its Composition and Evolution(Blackwell Scientific, Oxford, 1985).

    Google Scholar 

  11. McDonald, G. D. & Arnold, L. C. Geological and geochemical zoning of the Grasberg igneous complex, Irian Jaya, Indonesia. J. Geochem. Explor. 50, 143–178 (1994).

    Article  Google Scholar 

  12. Ulrich, T. in Actas X Congreso Latinoamericano de Geologia and VI Congreso Nacional de Geologia Economica 239 (Universidad de Buenos Aires, 1998).

    Google Scholar 

  13. Günther, D., Frischknecht, R., Heinrich, C. A. & Kahlert, H.-J. Capabilities of an argon fluoride 193nm excimer laser for laser ablation inductively coupled plasma mass spectrometry microanalysis of geological materials. J. Anal. Atom. Spectrosc. 12, 939–944 (1997).

    Article  Google Scholar 

  14. Günther, D., Audétat, A., Frischknecht, R. & Heinrich, C. A. Quantitative analysis of major, minor and trace elements in fluid inclusions using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). J. Anal. Atom. Spectrosc. 13, 263–270 (1998).

    Article  Google Scholar 

  15. Günther, D. & Heinrich, C. A. Enhanced sensitivity in laser ablation ICP-mass-spectrometry using helium-argon mixtures as aerosol carrier. J. Anal. Atom. Spectrosc.(submitted).

  16. Meinert, L. D., Hefton, K. K., Mayes, D. & Tasiran, I. Geology, zonation, and fluid evolution of the big gossan Cu-Au skarn, Ertsberg district, Irian Jaya. Econ. Geol. 92, 509–534 (1997).

    Article  CAS  Google Scholar 

  17. Wall, V. J. Bajo de la Alumbrera (Argentina). A world class copper gold deposit. Rev. Asoc. Argentina Geol. Econ. 11, 92–93 (1997).

    Google Scholar 

  18. Forrestal, P. MIM Holdings Limited, financial and production results. (cited Nov. 98) 〈http://www.mimholdings.com.au〉 (1998).

  19. Heinrich, C. A., Günther, D., Audétat, A., Ulrich, T. & Frischknecht, R. Metal fraction between magmatic brine and vapor, and the link between porphyry-style and epithermal Cu-Au deposits. Geology(in the press).

  20. Hemley, J. J. & Hunt, J. P. Hydrothermal ore-forming processes in the light of studies in rock-buffered systems: II. Some general geologic applications. Econ. Geol. 87, 23–43 (1992).

    Article  CAS  Google Scholar 

  21. Gammons, C. H. & Williams-Jones, A. E. Chemical mobility of gold in the porphyry-epithermal environment. Econ. Geol. 92, 45–59 (1997).

    Article  CAS  Google Scholar 

  22. Simon, G. Partitioning of gold between bornite and chalcopyrite in porphyry-copper-gold deposits: A thermodynamic and experimental approach. Econ. Geol.(submitted).

  23. Connors, K. A., Noble, D. C., Bussey, S. D. & Weiss, S. I. Initial gold contents of silicic volcanic rocks: Bearing on the behavior of gold in magmatic systems. Geology 21, 937–940 (1993).

    Article  ADS  CAS  Google Scholar 

  24. Wallace, D. A. The precious-metals potential of the Rockley volcanics in the Lachlan fold belt. Austral. Geol. Surv. Org. Res. Newsl. 24, 17–18 (1996).

    Google Scholar 

  25. Sasso, A. M. & Clark, A. H. The Farallón Negro group, northwestern Argentina: Magmatic, hydrothermal and tectonic evolution and implications for Cu-Au metallogeny in the Andean back-arc. Soc. Econ. Geol. Newsl. 34, 1–18 (1998).

    Google Scholar 

  26. Gill, J. Orogenic Andesites and Plate Tectonics(Springer, New York, 1981).

    Book  Google Scholar 

  27. Cline, J. S. in Porphyry Copper Deposits of the American Cordillera(eds Pierce, F. W. & Bolm, J. G.) 69–82 (Arizona Geological Soc., Tucson, 1995).

    Google Scholar 

  28. Naney, M. T. Phase equilibria of rock-forming ferromagnesian silicates in granitic systems. Am. J. Sci. 283, 993–1033 (1983).

    Article  ADS  CAS  Google Scholar 

  29. Candela, P. A. & Piccoli, P. M. in Magmas, Fluids, and Ore Deposits(ed. Thompson, J. F. H.) 101–127 (Mineralogical Soc. Canada, Victoria, British Columbia, 1995).

    Google Scholar 

  30. Kilinc, I. A. & Burnham, C. W. Partitioning of chloride between a silicate melt and coexisting aqueous phase from 2 to 8 kilobars. Econ. Geol. 67, 231–235 (1972).

    Article  CAS  Google Scholar 

  31. Nakano, T. & Urabe, T. Calculated composition of fluids released from a crystallizing granitic melt: Importance of pressure on the genesis of ore forming fluid. Geochem. J. 23, 307–319 (1989).

    Article  Google Scholar 

  32. Shinohara, H. Exsolution of immiscible vapor and liquid phases from a crystallizing silicate melt: Implications for chlorine and metal transport. Geochim. Cosmochim. Acta 58, 5215–5221 (1994).

    Article  ADS  CAS  Google Scholar 

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Acknowledgements

We thank MIM Exploration for financial and logistic support at Bajo de la Alumbrera, and Freeport Ltd for guidance at Grasberg. We thank H. Barnes, J. Hedenquist, S. Kesler and S. Matthai for critically reading the manuscript. Project and equipment funding by ETH Zürich and Schweizerischer Nationalfond is acknowledged.

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  1. D. Günther

    Present address: Laboratory of Inorganic Chemistry, ETH Zentrum, 8092, Zürich, Switzerland

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  1. Department of Earth Sciences, Isotope Geology and Mineral Resources, ETH Zentrum 8092, Zrich, Switzerland

    T. Ulrich, D. Günther & C. A. Heinrich

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Correspondence to C. A. Heinrich.

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Ulrich, T., Günther, D. & Heinrich, C. Gold concentrations of magmatic brines and the metal budget of porphyry copper deposits. Nature 399, 676–679 (1999). https://doi.org/10.1038/21406

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