Triggers for the formation of porphyry ore deposits in magmatic arcs

Journal name:
Nature Geoscience
Volume:
6,
Pages:
917–925
Year published:
DOI:
doi:10.1038/ngeo1940
Received
Accepted
Published online

Abstract

Porphyry ore deposits are the source of much of the copper, molybdenum, gold and silver used by humans. Porphyry ore typically forms in magmatic arcs above subduction zones. However, generation of the largest deposits is often restricted to specific arc segments and limited periods of time. Here, I outline a hierarchy of four key triggers that may be involved in the formation of large porphyry deposits. The first process is characterized by a cyclical enrichment of magmas with metals and water in the deep crust. Second, saturation of the magma with sulphide facilitates the concentration of metals into smaller volumes of material from which they can later be released. The third process is an efficient transfer of metals into hydrothermal fluids that are exsolved from the magmas. Finally, localized processes trigger the precipitation of ore minerals in the crust. Although some or all of these processes must act in concert to generate large ore deposits, I argue that sulphide saturation of the magma is the most important step and that this can explain the temporal and spatial distribution of ores. Consequently, the fingerprint of sulphide saturation in igneous rocks could be used to identify those parts of magmatic arcs that are particularly predisposed to ore formation.

References

  1. Seward, T. M. & Barnes, H. L. in Geochemistry of Hydrothermal Ore Deposits (ed. Barnes, H. L.) 435486 (Wiley, 1997).
  2. Yardley, B. W. D. Metal concentrations in crustal fluids and their relationship to ore formation. Econ. Geol. 100, 613632 (2005).
  3. Stoffell, B., Appold, M. S., Wilkinson, J. J., McLean, N. A. & Jeffries, T. E. Geochemistry and evolution of MVT mineralising brines from the tri-state and northern Arkansas districts determined by LA-ICP-MS microanalysis of fluid inclusions. Econ. Geol. 103, 14111435 (2008).
  4. Wilkinson, J. J., Stoffell, B., Wilkinson, C. C., Jeffries, T. E. & Appold, M. S. Anomalously metal-rich fluids form hydrothermal ore deposits. Science 323, 764767 (2009).
  5. Richard, A. et al. Giant uranium deposits formed from exceptionally uranium-rich acidic brines. Nature Geosci. 5, 142146 (2012).
  6. Pudack, C., Halter, W. E., Heinrich, C. A. & Pettke, T. Evolution of magmatic vapor to gold-rich epithermal liquid: The porphyry to epithermal transition at Nevados de Famatina, northwest Argentina. Econ. Geol. 104, 449477.
  7. Wilkinson, J. J., Simmons, S. F. & Stoffell, B. How metalliferous brines line Mexican epithermal veins with silver. Sci. Rep. 3, 2057 (2013).
  8. Heinrich, C. A., Günter, D., Audétat, A., Ulrich, T. & Frischknecht, R. Metal fractionation between magmatic brine and vapor determined by microanalysis of fluid inclusions. Geology 27, 755758 (1999).
  9. Heinrich, C. A. How fast does gold trickle out of volcanoes? Science 314, 263264 (2006).
  10. Audétat, A., Pettke, T., Heinrich, C. A. & Bodnar, R. J. The composition of magmatic-hydrothermal fluids in barren and mineralized intrusions. Econ. Geol. 103, 877908 (2008).
  11. Hedenquist, J. W. & Lowenstern, J. B. The role of magmas in the formation of hydrothermal ore deposits. Nature 370, 519527 (1994).
  12. John, D. A. et al. in Mineral Deposit Models for Resource Assessment Ch. B (US Geological Survey Scientific Investigations Report 2010-5070-B, 2010).
  13. Sillitoe, R. H. Porphyry copper systems. Econ. Geol. 105, 341 (2010).
  14. Richards, J. P. Magmatic to hydrothermal metal fluxes in convergent and collided margins. Ore Geol. Rev. 40, 126 (2011).
  15. Cooke, D. R., Hollings, P., Wilkinson, J. J. & Tosdal, R. M. in Mineral Deposits (ed. Scott, S. D.) Ch. 11 (Treatise on Geochemistry 2nd edn, Elsevier, 2013).
  16. 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, 719722 (2008).
  17. Cooke, D. R., Hollings, P. & Walshe, J. L. Giant porphyry deposits: Characteristics, distribution, and tectonic controls. Econ. Geol. 100, 801818 (2005).
  18. Winter, J. D. An Introduction to Igneous and Metamorphic Petrology (Prentice Hall, 2001).
  19. Burnham, C. W. in Geochemistry of Hydrothermal Ore Deposits 3rd edn (ed. Barnes, H. L.) 71136 (Wiley, 1979).
  20. Shinohara, H., Kazahaya, K. & Lowenstern, J. B. Volatile transport in a convecting magma column: Implications for porphyry Mo mineralization. Geology 23, 10911094 (1995).
  21. Proffett, J. M. High Cu grades in porphyry Cu deposits and their relationship to emplacement depth of magmatic sources. Geology 37, 675678 (2009).
  22. Dilles, J. H. The petrology of the Yerington batholith, Nevada: Evidence for the evolution of porphyry copper ore fluids. Econ. Geol. 82, 17501789 (1987).
  23. Candela, P. A. in Ore Deposition Associated with Magmas (eds Whitney, J. A. & Naldrett, A. J.) 223233 (Reviews in Economic Geology 4, Society of Economic Geologists, 1989).
  24. Fournier, R. O. Hydrothermal processes related to movement of fluid from plastic to brittle rock in the magmatic-epithermal environment. Econ. Geol. 94, 11931211 (1999).
  25. Sillitoe, R. H. in Porphyry and Hydrothermal Copper and Gold Deposits - A Global Perspective (ed. Porter, T. M.) 2134 (PGC, 1998).
  26. Richards, J. P. in Super Porphyry Copper and Gold Deposits - A Global Perspective Vol. 1 (ed. Porter, T. M.) 725 (PGC, 2005).
  27. Best, M. G. & Christiansen, E. H. Igneous Petrology (Blackwell Science, 2001).
  28. Manning, C. E. The chemistry of subduction-zone fluids. Earth Planet. Sci. Lett. 223, 116 (2004).
  29. Leeman, W. P. in Subduction: Top to Bottom (eds Bebout, G. E., Scholl, D. W., Kirby, S. H. & Platt, J. P.) 269276 (American Geophysical Union, 1996).
  30. Dreyer, B. M., Morris, J. D. & Gill, B. Incorporation of subducted slab-derived sediment and fluid in arc magmas: B-Be-10Be-εNd systematics of the Kurile convergent margin, Russia. J. Petrol. 51, 17611782 (2010).
  31. Bureau, H. & Keppler, H. Complete miscibility between silicate melts and hydrous fluids in the upper mantle: Experimental evidence and geochemical implications. Earth Planet. Sci. Lett. 165, 187196 (1999).
  32. Kessell, R., Schmidt, M. W., Ulmer, P. & Pettke, T. Trace element signature of subduction-zone fluids, melts and supercritical liquids at 120–180 km depth. Nature 437, 724727 (2005).
  33. Navon, O., Hutcheon, I. D., Rossman, G. R. & Wasserburg, G. J. Mantle-derived fluids in diamond micro-inclusions. Nature 335, 784789 (1988).
  34. Schiano, P. & Clocchiatti, R. Worldwide occurrence of silica-rich melts in sub-continental and sub-oceanic mantle minerals. Nature 368, 621624 (1994).
  35. Wulff-Pedersen, E., Neumann, E-R. & Jensen, B. B. The upper mantle under La Palma, Canary Islands: Formation of Si-K-Na-rich melt and its importance as a metasomatic agent. Contrib. Mineral. Petrol. 125, 113139 (1996).
  36. Mungall, J. E. Roasting the mantle: Slab melting and the genesis of major Au and Au-rich Cu deposits. Geology 30, 915918 (2002).
  37. Alt, J. C., Shanks, W. C. & Jackson, M. C. Cycling of sulfur in subduction zones: The geochemistry of sulfur in the Mariana Island Arc and back-arc trough. Earth Planet. Sci. Lett. 119, 477494 (1993).
  38. Gill, J. B. Orogenic Andesites and Plate Tectonics (Springer, 1981).
  39. McInnes, B. I. A., McBride, J. S., Evans, N. J., Lambert, D. D. & Andrew, A. S. Osmium isotope constraints on ore metal recycling in subduction zones. Science 286, 512516 (1999).
  40. Barnes, S-J. & Maier, W. D. in Dynamic Processes in Magmatic Ore Deposits and their Application in Mineral Exploration (eds Keays, R. R., Lesher, C. M., Lightfoot, P. C. & Farrow, C. E. G.) 69106 (Short Course 13, Geological Association of Canada, 1999).
  41. Jugo, P. J. Sulfur content at sulfide saturation in oxidized magmas. Geology 37, 415418 (2009).
  42. Lee, C-T. A. et al. Copper systematics in arc magmas and implications for crust-mantle differentiation. Science 336, 6468 (2012).
  43. DePaolo, D. J. Trace-element and isotopic effects of combined wallrock assimilation and fractional crystallisation. Earth Planet. Sci. Lett. 53, 189202 (1981).
  44. Hildreth, W. & Moorbath, S. Crustal contribution to arc magmatism in the Andes of central Chile. Contrib. Mineral. Petrol. 98, 455489 (1988).
  45. Annen, C., Blundy, J. & Sparks, R. S. J. The genesis of intermediate and silicic magmas in deep crustal hot zones. J. Petrol. 47, 505539 (2006).
  46. Core, D. P., Kesler, S. E. & Essene, E. J. Unusually Cu-rich magmas associated with giant porphyry copper deposits: Evidence from Bingham, Utah. Geology 34, 4144 (2006).
  47. Farmer, G. L. & DePaolo, D. J. Origin of Mesozoic and Tertiary granite in the western United States and implications for pre-Mesozoic crustal structure: 2. Nd and Sr isotopic studies of unmineralized and Cu-mineralized and Mo-mineralized granite in the Precambrian craton. J. Geophys. Res. 89, 141160 (1984).
  48. Pettke, T., Oberli, F. & Heinrich C. A. The magma and metal source of giant porphyry-type ore deposits, based on lead isotope microanalysis of individual fluid inclusions. Earth Planet. Sci. Lett. 296, 267277 (2010).
  49. Candela, P. A. & Piccoli, P. M. in Economic Geology 100th Anniversary Volume (eds Hedenquist, J. W., Thompson, J. F. H., Goldfarb, R. J. & Richards, J. P.) 2538 (Society of Economic Geologists, 2005).
  50. Wallace, P. J. Volatiles in subduction zone magmas: Concentrations and fluxes based on melt inclusion and volcanic gas data. J. Volcanol. Geotherm. Res. 140, 217240 (2005).
  51. Pokrovski, G. S., Borisova, A. Y. & Harrichoury, J-C. The effect of sulfur on vapour-liquid fractionation of metals in hydrothermal systems. Earth Planet. Sci. Lett. 266, 345362 (2008).
  52. Chiaradia, M., Ulianov, A., Kouzmanov, K. & Be, B. Why large porphyry Cu deposits like high Sr/Y magmas? Sci. Rep. 2, 685 (2012).
  53. Matzel, J. E. P., Bowring, S. A. & Miller, R. B. Time scales of pluton construction at differing crustal levels; examples from the Mount Stuart and Tenpeak intrusions, north Cascades. Geol. Soc. Am. Bull. 118, 14121430 (2006).
  54. Schaltegger, U. et al. Zircon and titanite recording 1.5 million years of magma accretion, crystallization and initial cooling in a composite pluton (southern Adamello batholith, northern Italy). Earth Planet. Sci. Lett. 286, 208218 (2009).
  55. Schoene, B. et al. Rates of magma differentiation and emplacement in a ballooning pluton recorded by U–Pb TIMS-TEA, Adamello batholith, Italy. Earth Planet. Sci. Lett. 355–356, 162173 (2012).
  56. Halter, W. E., Heinrich, C. A. & Pettke, T. Magma evolution and the formation of porphyry Cu-Au ore fluids: Evidence from silicate and sulfide melt inclusions. Miner. Deposita 39, 845863 (2005).
  57. Harris, A. C. et al. Multimillion year thermal history of a porphyry copper deposit: Application of U-Pb, 40Ar/39Ar and (U-Th)/He chronometers, Bajo de la Alumbrera copper-gold deposit, Argentina. Miner. Deposita 43, 295314 (2008).
  58. von Quadt, A. et al. Zircon crystallization and the lifetimes of ore-forming magmatic-hydrothermal systems. Geology 39, 731734 (2011).
  59. Glazner, A. F., Bartley, J. M., Coleman, D. S., Gray, W. & Taylor, Z. T. Are plutons assembled over millions of years by amalgamation from small magma chambers? GSA Today 14, 411 (2004).
  60. Sparks, R. S. J. & Marshall, L. A. Thermal and mechanical constraints on mixing between mafic and silicic magmas. J. Volcanol. Geotherm. Res. 29, 99124 (1986).
  61. Hattori, K. & Keith, J. D. Contribution of mafic melt to porphyry copper mineralization: Evidence from Mount Pinatubo, Philippines, and Bingham Canyon, Utah, USA. Miner. Deposita 36, 799806 (2001).
  62. Candela, P. A. & Holland, H. D. A mass transfer model for copper and molybdenum in magmatic hydrothermal systems: The origin of porphyry-type ore deposits. Econ. Geol. 81, 119 (1986).
  63. Webster, J. D. & Botcharnikov, R. E. in Sulfur in Magmas and Melts: Its Importance for Natural and Technical Processes (eds Behrens, H. & Webster, J. D.) 247283 (Reviews in Mineralogy and Geochemistry 73, Mineralogical Society of America, 2011).
  64. Seedorff, E. et al. in Economic Geology 100th Anniversary Volume (eds Hedenquist, J. W., Thompson, J. F. H., Goldfarb, R. J. & Richards, J. P.) 251298 (Society of Economic Geologists, 2005).
  65. 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, 91118 (2010).
  66. Williams-Jones, A. E., Migdisov, A. A., Archibald, S. M. & Xiao, Z. F. in Water-Rock Interactions, Ore Deposits, and Environmental Geochemistry (ed Hellman, R. & Wood, S. A.) 279305 (Geochemical Society Special Publication 7, Geochemical Society, 2002).
  67. Pokrovski, G. S., Roux, J. & Harrichoury, J. C. Fluid density control on vapor-liquid partitioning of metals in hydrothermal systems. Geology 33, 657660 (2005).
  68. Weis, P., Driesner, T. & Heinrich, C. A. Porphyry-copper ore shells form at stable pressure-temperature fronts within dynamic fluid plumes. Science 338, 16131616 (2012).
  69. Hemley, J. J. & Hunt, J. P. Hydrothermal ore-forming processes in the light of studies in rock-buffered systems: II. Some general geological applications. Econ. Geol. 87, 2343 (1992).
  70. Ingebritsen, S. E. & Manning, C. E. Permeability of the continental crust: Dynamic variations inferred from seismicity and metamorphism. Geofluids 10, 193205 (2010).
  71. Richards, J. P. Giant ore deposits formed by optimal alignments and combinations of geological processes. Nature Geosci. http://dx.doi.org/10.1038/ngeo1920 (2013).
  72. Halter, W. E., Pettke, T., Heinrich, T. & Heinrich, C. A. The origin of Cu/Au ratios in porphyry-type ore deposits. Science 296, 18441846 (2002).
  73. Harris, A. C., Kamenetsky, V. S., White, N. C., van Achterbergh, E. & Ryan, C. G. Melt inclusions in veins: Linking magmas and porphyry Cu deposits. Science 302, 21092111 (2003).
  74. Lickfold, V., Cooke, D. R., Crawford, A. J. & Fanning, C. Shoshonitic magmatism and the formation of the Northparkes porphyry Cu-Au deposits, New South Wales. Aus. J. Earth Sci. 54, 417444 (2007).
  75. 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, 501505 (2005).
  76. Keith, J. D. et al. The role of magmatic sulfides and mafic alkaline magmas in the Bingham and Tintic mining districts, Utah. J. Petrol. 38, 16791690 (1997).
  77. Rowland, M. R. & Wilkinson, J. J. in Water-Rock Interaction IX (eds Arehart, G. B. & Hulston, J. R.) 569573 (Balkema, 1998).
  78. Halter, W. E. et al. From andesitic volcanism to the formation of a porphyry Cu-Au mineralizing magma chamber: The Farallon Negro volcanic complex, northwestern Argentina. J. Volcanol. Geotherm. Res. 136, 130 (2004).
  79. Zajacz, Z. & Halter, W. Copper transport by high temperature, sulfur-rich magmatic vapor: Evidence from silicate melt and vapor inclusions in a basaltic andesite from the Villarrica volcano (Chile). Earth Planet. Sci. Lett. 282, 115121 (2009).
  80. Sillitoe, R. H. Major gold deposits and belts of the North and South American Cordillera: Distribution, tectonomagmatic settings, and metallogenic considerations. Econ. Geol. 103, 663687 (2008).
  81. Rohrlach, B. D. & Loucks, R. R. in Super Porphyry Copper and Gold Deposits - A Global Perspective Vol. 2 (ed. Porter, T. M.) 369407 (PGC, 2005).
  82. Loucks, R. Chemical characteristics, geodynamic settings, and petrogenesis of copper ore-forming arc magmas. CET Quarterly News 19, 110 (2012).
  83. Rooney, T. O., Franceschi, P. & Hall, C. M. Water-saturated magmas in the Panama Canal region: A precursor to adakite-like magma generation? Contrib. Mineral. Petrol. 161, 373388 (2011).
  84. Simon, A. C. & Ripley, E. M. in Sulfur in Magmas and Melts: Its Importance for Natural and Technical Processes (eds Behrens, H. & Webster, J. D.) 513578 (Reviews in Mineralogy and Geochemistry 73, Mineralogical Society of America, 2011).
  85. Simon, A. C., Pettke, T., Candela, P. A., Piccoli, P. M. & Heinrich, C. A. Copper partitioning in a melt-vapor-brine-magnetite-pyrrhotite assemblage. Geochim. Cosmochim. Acta 70, 55835600 (2006).
  86. 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, 24452464 (2010).
  87. Bell, A., Simon, A. & Guillong, M. Experimental constraints on Pt, Pd, and Au partitioning in silicate melt-sulfide-oxide-aqueous fluid systems at 800°C, 150 MPa, and variable sulfur fugacity. Geochim. Cosmochim. Acta 73, 57785792 (2009).
  88. Larocque, A. C. L., Stimac, J. A., Keith, J. D. & Huminicki, M. A. E. Evidence for open-system behavior in immiscible Fe-S-O liquids in silicate magmas: Implications for contributions of metals and sulfur to ore-forming fluids. Can. Mineral. 38, 12331249 (2000).
  89. Ulrich, T., Günther, D. & Heinrich, C. A. Gold concentrations of magmatic brines and the metal budget of porphyry copper deposits. Nature 399, 676679 (1999).
  90. Rusk, B. G., Reed, M. H., Dilles, J. H., Klemm, L. M. & Heinrich, C. A. Compositions of magmatic hydrothermal fluids determined by LA-ICP-MS of fluid inclusions from the porphyry copper-molybdenum deposit at Butte, MT. Chem. Geol. 210, 173199 (2004).
  91. Wilkinson, J. J. et al. Ore fluid chemistry in super-giant porphyry copper deposits. Proc. PACRIM 2008 Congress 295298 (Australasian Institute of Mining and Metallurgy, 2008).
  92. Bell, A. S., Simon, A. & Guillong, M. Gold solubility in oxidized and reduced, water-saturated mafic melt. Geochim. Cosmochim. Acta 75, 17181732 (2011).
  93. Sun, W., Arculus, R. J., Kamenetsky, V. S. & Binns, R. A. Release of gold-bearing fluids in convergent margin magmas prompted by magnetite crystallization. Nature 431, 975978 (2004).
  94. Stanton, R. L. Ore Elements in Arc Lavas (Oxford Univ. Press, 1994).
  95. Cloos, M. Bubbling magma chambers, cupolas, and porphyry copper deposits. Int. Geol. Rev. 43, 285311 (2001).
  96. Mathur, R., Titley, S., Ruiz, J., Gibbins, S. & Friehauf, K. A Re-Os isotope study of sedimentary rocks and copper-gold ores from the Ertsberg district, West Papua, Indonesia. Ore Geol. Rev. 26, 207226 (2005).
  97. Crerar, D. A. & Barnes, H. L. Ore solution chemistry V: Solubilities of chalcopyrite and chalcocite assemblages in hydrothermal solution at 200° to 350°C. Econ. Geol. 71, 772794 (1976).
  98. Audétat, A., Günther, D. & Heinrich, C. A. Causes for large-scale metal zonation around mineralized plutons: Fluid inclusion LA-ICP-MS evidence from the Mole Granite, Australia. Econ. Geol. 95, 15631581 (2000).
  99. Stoffell, B., Wilkinson, J. J. & Jeffries, T. E. Metal transport and deposition in hydrothermal veins revealed by 213nm UV laser ablation microanalysis of single fluid inclusions. Am. J. Sci. 304, 533557 (2004).

Download references

Author information

Affiliations

  1. Department of Earth Science and Engineering, Imperial College London, South Kensington Campus, Exhibition Road, London SW7 2AZ, UK

    • Jamie J. Wilkinson
  2. ARC Centre of Excellence in Ore Deposits (CODES), University of Tasmania, Hobart, Tasmania 7001, Australia

    • Jamie J. Wilkinson
  3. Department of Earth Sciences, Natural History Museum, Cromwell Road, London SW7 5BD, UK

    • Jamie J. Wilkinson

Competing financial interests

The author declares no competing financial interests.

Corresponding author

Correspondence to:

Author details

Supplementary information

PDF files

  1. Supplementary Information (216 KB)

    Mineralization model for porphyry ore deposits

Additional data