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  • Review Article
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Formation of iron oxide–apatite deposits

Nature Reviews Earth & Environment volume 3, pages 758–775 (2022)Cite this article

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Abstract

Renewed economic interest in iron oxide–apatite (IOA) deposits — containing tens to hundreds of millions of tonnes of Fe and substantial amounts of rare earth elements, P, Co and V — has emerged to supply the sustainable energy transition. However, the mechanisms that efficiently concentrate dense iron-rich minerals (for example, in ores up to ~90% magnetite) at the Earth’s near-surface are widely debated. In this Review, we discuss synergistic combinations of magmatic and hydrothermal iron-enrichment processes that can explain the available geochemical, petrological and geological IOA data. IOA deposits typically evolve from subduction-related water-rich and chlorine-rich intermediate magmas under a wide temperature range, almost spanning the whole igneous–hydrothermal spectrum (from ~1,000 to 300 °C). Magmatic–hydrothermal fluids could efficiently scavenge Fe from magmas to form large IOA deposits (>100 million tonnes of Fe), whereas crystal fractionation and liquid immiscibility processes might account for more minor Fe mineralization occurrences. Igneous magnetite crystallization, volatile exsolution and highly focused transport of Fe-rich hydrothermal fluids through the crust under extensional tectonic conditions could be key factors enabling concentration of dense magnetite minerals in the less-dense upper crust. Future research should target both fertile and barren mafic–intermediate magmatic suites for distinctive signatures diagnostic of metallogenic fertility, to help unravel the genetic linkage between IOA and iron oxide–copper–gold systems.

Key points

  • Iron oxide–apatite deposits can form from purely igneous (~1,000–800 °C), through late magmatic or magmatic–hydrothermal (~800–600 °C), to purely hydrothermal (<600 °C) conditions. Cooling trends are identified at deposit to mineral grain scales.

  • IOA mineralization is fundamentally controlled by temperature, but relative depth of formation and structural level of emplacement are also relevant factors.

  • The source of Fe and other minor metals (for example, Cu and Co) is predominantly linked to intermediate magmas and magmatically derived aqueous fluids, but in some cases there may be a minor contribution from low-temperature, non-magmatic hydrothermal fluids.

  • Mechanisms of Fe enrichment are diverse and include a combination of magmatic and hydrothermal processes operating in upper crustal silicate magma reservoirs. Although the relative contributions of each mechanism are still contended, we suggest that magmatic–hydrothermal fluids can efficiently scavenge Fe from magmas to form the largest IOA deposits, whereas crystal fractionation and liquid immiscibility processes might account for smaller Fe mineralization occurrences.

  • Tectonic stress changes are key to the formation of large IOA deposits. Fault tapping of silicate magma reservoirs allows for rapid ascent of Fe-rich magmatic–hydrothermal fluids, decompression, and magnetite precipitation upon cooling.

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Fig. 1: Spatial and temporal distribution of main iron oxide–apatite districts.
Fig. 2: Temperature and depth conditions of magnetite formation.
Fig. 3: Metal source of IOA deposits.
Fig. 4: Experimental evidence of iron-enrichment processes.
Fig. 5: Possible modes of IOA deposit formation in a volcanic arc setting.

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Data availability

Compilation of EMPA and LA-ICP-MS analyses of magnetite from Chilean IOA deposits is available in the online Supplementary Data file.

References

  1. Watari, T., Nansai, K. & Nakajima, K. Major metals demand, supply, and environmental impacts to 2100: a critical review. Resour. Conserv. Recycl. 164, 105107 (2021).

    Article  Google Scholar 

  2. Arndt, N. T. et al. Future global mineral resources. Geochem. Perspect. https://doi.org/10.7185/geochempersp.6.1 (2017).

    Article  Google Scholar 

  3. Morfeldt, J., Nijss, W. & Silveira, S. The impact of climate targets on future steel production — an analysis based on a global energy system model. J. Clean. Prod. 103, 469–482 (2015).

    Article  Google Scholar 

  4. Song, Y., Wang, N. & Yu, A. Temporal and spatial evolution of global iron ore supply-demand and trade structure. Res. Policy 64, 101506 (2019).

    Article  Google Scholar 

  5. Nassar, N. T. & Fortier, S. M. Methodology and technical input for the 2021 review and revision of the U.S. Critical Minerals List. Open-File Report 2021–1045, 31 (US Geological Survey, 2021).

  6. Pell, R. et al. Towards sustainable extraction of technology materials through integrated approaches. Nat. Rev. Earth Environ. 2, 665–679 (2021).

    Article  Google Scholar 

  7. Jowitt, S. M., Mudd, G. M. & Thompson, J. F. H. Future availability of non-renewable metal resources and the influence of environmental, social, and governance conflicts on metal production. Commun. Earth Environ. 1, 13 (2020).

    Article  Google Scholar 

  8. Park, C. F. A magnetite ‘flow’ in northern Chile. Econ. Geol. 56, 431–444 (1961).

    Article  Google Scholar 

  9. Henriquez, F. & Martin, R. F. Crystal growth textures in magnetite flows and feeder dykes, El Laco, Chile. Can. Mineral. 16, 581–589 (1978).

    Google Scholar 

  10. Henríquez, F. & Nyström, J. O. Magnetite bombs at El Laco volcano, Chile. GFF 120, 269–271 (1998).

    Article  Google Scholar 

  11. Nyström, J. O., Henríquez, F., Naranjo, J. A. & Naslund, H. R. Magnetite spherules in pyroclastic iron ore at El Laco, Chile. Am. Mineral. 101, 587–595 (2016).

    Article  Google Scholar 

  12. Tornos, F., Velasco, F. & Hanchar, J. M. Iron-rich melts, magmatic magnetite, and superheated hydrothermal systems: the El Laco deposit, Chile. Geology 44, 427–430 (2016).

    Article  Google Scholar 

  13. Mungall, J. E., Long, K., Brenan, J. M., Smythe, D. & Naslund, H. R. Immiscible shoshonitic and Fe-P-oxide melts preserved in unconsolidated tephra at El Laco volcano, Chile. Geology 46, 255–258 (2018).

    Article  Google Scholar 

  14. Ovalle, J. T. et al. Formation of massive iron deposits linked to explosive volcanic eruptions. Sci. Rep. 8, 14855 (2018).

    Article  Google Scholar 

  15. Frietsch, R. On the magmatic origin of iron ores of the Kiruna type. Econ. Geol. 73, 478–485 (1978).

    Article  Google Scholar 

  16. Förster, H. & Jafarzadeh, A. The Bafq mining district in Central Iran: a highly mineralized Infracambrian volcanic field. Econ. Geol. 89, 1697–1721 (1994).

    Article  Google Scholar 

  17. Nyström, J. O. & Henriquez, F. Magmatic features of iron ores of the Kiruna type in Chile and Sweden; ore textures and magnetite geochemistry. Econ. Geol. 89, 820–839 (1994).

    Article  Google Scholar 

  18. Allen, R. L., Lundström, I., Ripa, M., Simeonov, A. & Christofferson, H. Facies analysis of a 1.9 Ga, continental margin, back-arc felsic caldera province with diverse Zn-Pb-Ag-(Cu-Au) sulphide and Fe oxide deposits, Bergslagen region, Sweden. Econ. Geol. 91, 979–1008 (1996).

    Article  Google Scholar 

  19. Day, W. C., Slack, J. F., Ayuso, R. A. & Seeger, C. M. Regional geologic and petrologic framework for iron oxide ± apatite ± rare earth element and iron oxide copper-gold deposits of the Mesoproterozoic St. Francois Mountains Terrane, Southeast Missouri, USA. Econ. Geol. 111, 1825–1858 (2016).

    Article  Google Scholar 

  20. Palma, G., Barra, F., Reich, M., Simon, A. C. & Romero, R. A review of magnetite geochemistry of Chilean iron oxide–apatite (IOA) deposits and its implications for ore-forming processes. Ore Geol. Rev. 126, 103748 (2020).

    Article  Google Scholar 

  21. Palma, G. et al. Thermal evolution of Andean iron oxide–apatite (IOA) deposits as revealed by magnetite thermometry. Sci. Rep. 11, 18424 (2021).

    Article  Google Scholar 

  22. Philpotts, A. R. Origin of certain iron-titanium oxide and apatite rocks. Econ. Geol. 62, 303–315 (1967).

    Article  Google Scholar 

  23. Kolker, A. Mineralogy and geochemistry of Fe-Ti oxide and apatite (Nelsonite) deposits and evaluation of the liquid immiscibility hypothesis. Econ. Geol. 77, 1146–1158 (1982).

    Article  Google Scholar 

  24. Naslund, H. R., Henríquez, F., Nyström, J. O., Vivallo, W. & Dobbs, F. M. in Hydrothermal Iron Oxide Copper-Gold and Related Deposits: A Global Perspective Vol. 2 (ed. Porter, T. M.) 207–226 (PGC, 2002).

  25. Lester, G. W., Clark, A. H., Kyser, T. K. & Naslund, H. R. Experiments on liquid immiscibility in silicate melts with H2O, P, S, F and Cl: implications for natural magmas. Contrib. Mineral. Petrol. 166, 329–349 (2013).

    Article  Google Scholar 

  26. Velasco, F., Tornos, F. & Hanchar, J. M. Immiscible iron- and silica-rich melts and magnetite geochemistry at the El Laco volcano (northern Chile): evidence for a magmatic origin for the magnetite deposits. Ore Geol. Rev. 79, 346–366 (2016).

    Article  Google Scholar 

  27. Hou, T. et al. Immiscible hydrous Fe–Ca–P melt and the origin of iron oxide-apatite ore deposits. Nat. Commun. 9, 1415 (2018).

    Article  Google Scholar 

  28. Lledo, H. L., Naslund, H. R. & Jenkins, D. M. Experiments on phosphate–silicate liquid immiscibility with potential links to iron oxide apatite and nelsonite deposits. Contrib. Mineral. Petrol. 175, 111 (2020).

    Article  Google Scholar 

  29. Bookstrom, A. A. Magmatic features of iron ores of the Kiruna type in Chile and Sweden: ore textures and magnetite geochemistry — a discussion. Econ. Geol. 90, 469–475 (1995).

    Article  Google Scholar 

  30. Ménard, J. J. Relationship between altered pyroxene diorite and the magnetite mineralization in the Chilean iron belt, with emphasis on the El Algarrobo iron deposits (Atacama region, Chile). Miner. Deposita 30, 268–274 (1995).

    Article  Google Scholar 

  31. Rhodes, A. L. & Oreskes, N. Magnetite deposition at El Laco, Chile: implications for Fe-oxide formation in magmatic-hydrothermal systems. In Giant Ore Deposits II: Controls on the Scale of Orogenic Magmatic-Hydrothermal Mineralization: Proc. Second Giant Ore Deposits Workshop (ed. Clark, A. H.) 582–622 (Department of Geological Sciences, Queen’s Univ., 1995).

  32. Barton, M. D. & Johnson, D. A. Evaporitic-source model for igneous-related Fe-oxide (REE–Cu–Au–U) mineralization. Geology 24, 259–262 (1996).

    Article  Google Scholar 

  33. Rhodes, A. L., Oreskes, N. & Sheets, R. W. Geology and REE geochemistry of the magnetite deposits at El Laco, Chile. Econ. Geol. Spec. Publ. 7, 299–332 (1999).

    Google Scholar 

  34. Rhodes, A. L. & Oreskes, N. in Geology and Ore Deposits of the Central Andes 7 (ed. Skinner, B. J.) 333–351 (Society of Economic Geologists Special Publication, 1999).

  35. Haynes, D. W. in Hydrothermal Iron Oxide-Copper-Gold and Related Deposits: A Global Perspective Vol. 1 (ed. Porter, T. M.) 71–90 (PGC, 2000).

  36. Sillitoe, R. H. & Burrows, D. R. New field evidence bearing on the origin of the El Laco magnetite deposit, northern Chile. Econ. Geol. 97, 1101–1109 (2002).

    Google Scholar 

  37. Dare, S. A. S., Barnes, S. J. & Beaudoin, G. Did the massive magnetite ‘lava flows’ of El Laco (Chile) form by magmatic or hydrothermal processes? New constraints from magnetite composition by LA-ICP-MS. Miner. Deposita 50, 607–617 (2015).

    Article  Google Scholar 

  38. Peters, S. T. M. et al. Triple oxygen isotope variations in magnetite from iron-oxide deposits, central Iran, record magmatic fluid interaction with evaporite and carbonate host rocks. Geology 48, 211–215 (2020).

    Article  Google Scholar 

  39. Hitzman, M. W., Oreskes, N. & Einaudi, M. T. Geological characteristics and tectonic setting of Proterozoic iron oxide (Cu–U–Au–REE) deposits. Precam. Res. 58, 241–287 (1992).

    Article  Google Scholar 

  40. Hitzman, M. W. in Hydrothermal Iron Oxide Copper-Gold and Related Deposits: A Global Perspective Vol. 1 (ed. Porter, T. M.) 9–26 (PGC, 2000).

  41. Williams, P. J. et al. Iron oxide copper-gold deposits: geology, space-time distribution, and possible modes of origin. Econ. Geol. 100th Anniv. Vol., 371–405 (2005).

  42. Groves, D. I., Bierlein, F. P., Meinert, L. D. & Hitzman, M. W. Iron oxide copper-gold (IOCG) deposits through Earth history: implications for origin, lithospheric setting, and distinction from other epigenetic iron oxide deposits. Econ. Geol. 105, 641–654 (2010).

    Article  Google Scholar 

  43. Barton, M. D. in Treatise of Geochemistry Vol. 13 (eds. Holland, H. & Turekian, K.) 515–536 (Univ. Arizona, 2014).

  44. Barra, F. et al. Unraveling the origin of the Andean IOCG clan: a Re-Os isotope approach. Ore Geol. Rev. 81, 62–78 (2017).

    Article  Google Scholar 

  45. Rojas, P. et al. A genetic link between magnetite mineralization and diorite intrusion at the El Romeral iron oxide-apatite deposit, northern Chile. Miner. Deposita 53, 947–966.

  46. Simon, A. C. et al. Kiruna-type iron oxide-apatite (IOA) and iron oxide copper-gold (IOCG) deposits form by a combination of igneous and magmatic-hydrothermal processes: evidence from the Chilean iron belt. Soc. Econ. Geol. Spec. Pub. 21, 89–114 (2018).

    Google Scholar 

  47. Sillitoe, R. H. Iron oxide-copper-gold deposits: an Andean view. Miner. Deposita 38, 787–812 (2003).

    Article  Google Scholar 

  48. Espinoza, R. S., Véliz, G. H., Esquivel, L. J., Arias, F. J. & Moraga, B. A. The cupriferous province of the Coastal Range, northern Chile. In Andean Copper Deposits: New Discoveries, Mineralization Styles and Metallogeny, 5 (eds. Camus, F. et al.) 19–32 (Society of Economic Geologists Special Publication, 1996).

  49. Reich, M. et al. Trace element signature of pyrite from the Los Colorados iron oxide-apatite (IOA) deposit, Chile: A missing link between Andean IOA and iron oxide-copper-gold systems? Econ. Geol. 111, 743–761 (2016).

    Article  Google Scholar 

  50. Apukhtina, O. B. et al. Early, deep magnetite-fluorapatite mineralization at the Olympic Dam Cu-U-Au-Ag deposit, South Australia. Econ. Geol. 112, 1531–1542 (2017).

    Article  Google Scholar 

  51. Rodriguez-Mustafa, M. A. et al. A continuum from iron oxide copper-gold to iron oxide-apatite deposits: evidence from Fe and O stable isotopes and trace element chemistry of magnetite. Econ. Geol. 115, 1443–1459 (2020).

    Article  Google Scholar 

  52. Verdugo-Ihl, M. R., Ciobanu, C. L., Cook, N. J., Ehrig, K. J. & Courtney-Davies, L. Defining early stages of IOCG systems: evidence from iron oxides in the outer shell of the Olympic Dam deposit, South Australia. Miner. Deposita 55, 429–452 (2020).

    Article  Google Scholar 

  53. Rodriguez-Mustafa, M. A. et al. The Mina Justa iron oxide copper-gold (IOCG) deposit, Peru: constraints on metal and ore fluid sources. Econ. Geol. https://doi.org/10.5382/econgeo.4875 (2021).

    Article  Google Scholar 

  54. Skirrow, R. G. Iron oxide copper-gold (IOCG) deposits — a review (part 1): settings, mineralogy, ore geochemistry and classification. Ore Geol. Rev. 140, 104569 (2022).

    Article  Google Scholar 

  55. Dymek, R. & Owens, B. Petrogenesis of apatite-rich rocks (nelsonites and oxide-apatite gabbronorites) associated with massif anorthosites. Econ. Geol. 96, 797–815 (2001).

    Google Scholar 

  56. Tegner, C., Cawthorn, R. G. & Kruger, F. J. Cyclicity in the main and upper zones of the bushveld complex, south africa: crystallization from a zoned magma sheet. J. Petrol. 47, 2257–2279 (2006).

    Article  Google Scholar 

  57. Tollari, N., Barnes, S.-J., Cox, R. A. & Nabil, H. Trace element concentrations in apatites from the Sept-Îles Intrusive Suite, Canada — implications for the genesis of nelsonites. Chem. Geol. 252, 180–190 (2008).

    Article  Google Scholar 

  58. Charlier, B. et al. The Grader layered intrusion (Havre-Saint-Pierre anorthosite, Quebec) and genesis of nelsonite and other Fe-Ti-P ores. Lithos 101, 359–378 (2008).

    Article  Google Scholar 

  59. Treloar, P. J. & Colley, H. Variations in F and Cl contents in apatites from magnetite-apatite ores in northern Chile, and their ore-genetic implications. Mineral. Mag. 60, 285–301 (1996).

    Article  Google Scholar 

  60. Knipping, J. L. et al. Giant Kiruna-type deposits form by efficient flotation of magmatic magnetite suspensions. Geology 43, 591–594 (2015).

    Article  Google Scholar 

  61. Zhang, Z. et al. Spatio-temporal distribution and tectonic settings of the major iron deposits in China: an overview. Ore Geol. Rev. 57, 247–263 (2014).

    Article  Google Scholar 

  62. Taylor, R. D., Shah, A. K., Walsh, G. J. & Taylor, C. D. Geochemistry and geophysics of iron oxide-apatite (IOA) deposits and associated waste piles with implications for potential rare earth element (REE) resources from ore and historic mine waste in the eastern Adirondack Highlands, New York, USA. Econ. Geol. 114, 1569–1598 (2019).

    Article  Google Scholar 

  63. Lyons, J. I. Volcanogenic iron oxide deposits, Cerro de Mercado and vicinity, Durango, Mexico. Econ. Geol. 83, 1886–1906 (1988).

    Article  Google Scholar 

  64. Chen, H. et al. Evolution of the Giant Marcona-Mina Justa iron oxide-copper-gold district, south-central Peru. Econ. Geol. 105, 155–185 (2010).

    Article  Google Scholar 

  65. Corriveau, L., Montreuil, J.-F. & Potter, E. G. Alteration facies linkages among iron oxide copper-gold, iron oxide-apatite, and affiliated deposits in the Great Bear magmatic zone, Northwest Territories, Canada. Econ. Geol. 111, 2045–2072 (2016).

    Article  Google Scholar 

  66. Ootes, L. et al. A Paleoproterozoic Andean-type iron oxide copper-gold environment, the Great Bear magmatic zone, Northwest Canada. Ore Geol. Rev. 81, 123–139 (2017).

    Article  Google Scholar 

  67. Helvaci, C. Apatite-rich iron deposits of the Avnik (Bingol) region, southeastern Turkey. Econ. Geol. 79, 354–371 (1984).

    Article  Google Scholar 

  68. He, X. F., Santosh, M., Tsunogae, T. & Malaviarachchi, S. P. K. Magnetite-apatite deposit from Sri Lanka: implications on Kiruna-type mineralization associated with ultramafic intrusion and mantle metasomatism. Am. Mineral. 103, 26–38 (2018).

    Article  Google Scholar 

  69. Seo, J., Choi, S. G., Kim, D. W., Park, J. W. & Oh, C. W. A new genetic model for the Triassic Yangyang iron-oxide-apatite deposit, South Korea: constraints from in situ U-Pb and trace element analyses of accessory minerals. Ore Geol. Rev. 70, 110–135 (2015).

    Article  Google Scholar 

  70. Sun, W. et al. Geochronology and geochemistry of the Fe ore-bearing Zhonggu intrusions of the Ningwu basin: implications for tectonic setting and contemporaneous Cu-Au mineralization in the Middle–Lower Yangzte Metallogenic Belt. Ore Geol. Rev. 84, 246–272 (2017).

    Article  Google Scholar 

  71. Sun, W. et al. In situ LA–ICP–MS trace element analyses of magnetite: genetic implications for the Zhonggu orefield, Ningwu volcanic basin, Anhui Province, China. Miner. Deposita 54, 1243–1264 (2019).

    Article  Google Scholar 

  72. Parak, T. Kiruna iron ores are not intrusive-magmatic ores of the Kiruna type. Econ. Geol. 70, 1242–1258 (1975).

    Article  Google Scholar 

  73. Romer, R., Martinsson, O. & Perdahl, J. Geochronology of the Kiruna iron ores and hydrothermal alterations. Econ. Geol. 89, 1249–1261 (1994).

    Article  Google Scholar 

  74. Martinsson, O. Geology and metallogeny of the Northern Norrbotten Fe-Cu-Au province. Soc. Econ. Geol. Guideb. Ser. 33, 131–148 (2004).

    Google Scholar 

  75. Westhues, A., Hanchar, J. M., Whitehouse, M. J. & Martinsson, O. New constraints on the timing of host-rock emplacement, hydrothermal alteration, and iron oxide-apatite mineralization in the Kiruna district, Norrbotten, Sweden. Econ. Geol. 111, 1595–1618 (2016).

    Article  Google Scholar 

  76. Westhues, A., Hanchar, J. M., LeMessurier, M. & Whitehouse, M. J. Evidence for hydrothermal alteration and source regions for the Kiruna iron oxide-apatite ore (northern Sweden) from zircon Hf and O isotopes. Geology 45, 571–574 (2017).

    Article  Google Scholar 

  77. Westhues, A. et al. Tracing the fluid evolution of the Kiruna iron oxide apatite deposits using zircon, monazite, and whole rock trace elements and isotopic studies. Chem. Geol. 466, 303–322 (2017).

    Article  Google Scholar 

  78. Andersson, J. B. H., Bauer, T. E. & Martinsson, O. Structural evolution of the Central Kiruna Area, Northern Norrbotten, Sweden: implications on the geologic setting generating iron oxide-apatite and epigenetic iron and copper sulfides. Econ. Geol. 116, 1981–2009 (2021).

    Article  Google Scholar 

  79. Jonsson, E. et al. Magmatic origin of giant ‘Kiruna-type’ apatite-iron-oxide ores in Central Sweden. Sci. Rep. 3, 1644 (2013).

    Article  Google Scholar 

  80. Jonsson, E., Harlov, D. E., Majka, J., Högdahl, K. & Persson-Nilsson, K. Fluorapatite-monazite-allanite relations in the Grängesberg apatite-iron oxide ore district, Bergslagen, Sweden. Am. Mineral. 101, 1769–1782 (2016).

    Article  Google Scholar 

  81. Slack, J. F., Corriveau, L. & Hitzman, M. W. A special issue devoted to proterozoic iron oxide-apatite (± REE) and iron oxide copper-gold and affiliated deposits of Southeast Missouri, USA, and the Great Bear Magmatic Zone, Northwest Territories, Canada: Preface. Econ. Geol. 111, 1803–1814 (2016).

    Article  Google Scholar 

  82. Nold, J. L., Dudley, M. A. & Davidson, P. The southeast Missouri (USA) Proterozoic iron metallogenic province — types of deposits and genetic relationships to magnetite-apatite and iron oxide-copper-gold deposits. Ore Geol. Rev. 57, 154–171 (2014).

    Article  Google Scholar 

  83. Day, W. C. & Granitto, M. Geologic field notes and geochemical analyses of outcrop and drill core from Mesoproterozoic rocks and iron-oxide deposits and prospects of southeast Missouri. Open-File Report 2014-1053 (USGS, 2014).

  84. Childress, T. M., Simon, A. C., Day, W. C., Lundstrom, C. C. & Bindeman, I. N. Iron and oxygen isotope signatures of the Pea Ridge and Pilot Knob magnetite-apatite deposits, Southeast Missouri, USA. Econ. Geol. 111, 2033–2044 (2016).

    Article  Google Scholar 

  85. Nold, J. L., Davidson, P. & Dudley, M. A. The Pilot Knob magnetite deposit in the Proterozoic St. Francois Mountains terrane, southeast Missouri, USA: a magmatic and hydrothermal replacement iron deposit. Ore Geol. Rev. 53, 446–469 (2013).

    Article  Google Scholar 

  86. Mercer, C. N., Watts, K. E. & Gross, J. Apatite trace element geochemistry and cathodoluminescent textures — a comparison between regional magmatism and the Pea Ridge IOA-REE and Boss IOCG deposits, southeastern Missouri iron metallogenic province, USA. Ore Geol. Rev. 116, 103129 (2020).

    Article  Google Scholar 

  87. Watts, K. E. & Mercer, C. N. Zircon-hosted melt inclusion record of silicic magmatism in the Mesoproterozoic St. Francois Mountains terrane, Missouri: origin of the Pea Ridge iron oxide-apatite-rare earth element deposit and implications for regional crustal pathways of mineralization. Geochim. Cosmochim. Acta 272, 54–77 (2020).

    Article  Google Scholar 

  88. Tunnell et al. The Pilot Knob iron ore deposits in southeast Missouri, USA: a high-to-low temperature magmatic-hydrothermal continuum. Ore Geol. Rev. 131, 103973 (2021).

    Article  Google Scholar 

  89. Aleinikoff, J. N. et al. U-Pb, Re-Os, and Ar/Ar geochronology of rare earth element (REE)-rich breccia pipes and associated host rocks from the Mesoproterozoic Pea Ridge Fe-REE-Au deposit, S. Francois Mountains, Missouri. Econ. Geol. 111, 1883–1914 (2016).

    Article  Google Scholar 

  90. Neymark, L. A. et al. High spatial resolution U-Pb geochronology and Pb isotope geochemistry of magnetite-apatite ore from the Pea Ridge iron oxide-apatite deposit, St. Francois Mountains, southeast Missouri, USA. Econ. Geol. 111, 1915–1933 (2016).

    Article  Google Scholar 

  91. Ayuso, R. A., Slack, J. F., Day, W. C. & McCafferty, A. E. Geochemistry, Nd-Pb isotopes, and Pb-Pb ages of Mesoproterozoic Pea Ridge iron oxide-apatite-rare earth element deposit, southeast Missouri. Econ. Geol. 111, 1935–1962 (2016).

    Article  Google Scholar 

  92. Hofstra, A. H. et al. Mineral thermometry and fluid inclusion studies of the Pea Ridge iron oxide-apatite-rare earth element deposit, Mesoproterozoic St. Francois Mountains Terrane, Southeast Missouri, USA. Econ. Geol. 111, 1985–2016 (2016).

    Article  Google Scholar 

  93. Daliran, F. in Hydrothermal Iron Oxide-Copper-Gold and Related Deposits: A Global Perspective Vol. 2 (ed. Porter, T. M.) 303–320 (PGC, 2002).

  94. Torab, F. M. & Lehmann, B. Magnetite-apatite deposits of the Bafq district, Central Iran: apatite geochemistry and monazite geochronology. Mineral. Mag. 71, 347–363 (2007).

    Article  Google Scholar 

  95. Mokhtari, M. A. A., Zadeh, G. H. & Emami, M. H. Genesis of iron-apatite ores in Posht-e-Badam Block (Central Iran) using REE geochemistry. J. Earth Syst. Sci. 122, 795–807 (2013).

    Article  Google Scholar 

  96. Heidarian, H., Alirezaei, S. & Lentz, D. R. Chadormalu Kiruna-type magnetite-apatite deposit, Bafq district, Iran: insights into hydrothermal alteration and petrogenesis from geochemical, fluid inclusion, and sulfur isotope data. Ore Geol. Rev. 83, 43–62 (2017).

    Article  Google Scholar 

  97. Heidarian, H., Lentz, D., Alirezaei, S., McFarlane, C. & Peighambari, S. Multiple stage ore formation in the Chadormalu Iron Deposit, Bafq Metallogenic Province, Central Iran: evidence from BSE imaging and apatite EPMA and LA-ICP-MS U-Pb geochronology. Minerals 8, 87 (2018).

    Article  Google Scholar 

  98. Ziapour, S., Esmaeily, D., Khoshnoodi, K., Niroomand, S. & Simon, A. C. Mineralogy, geochemistry, and genesis of the Chahgaz (XIVA anomaly) Kiruna-type iron oxide-apatite (IOA) deposit, Bafq district, Central Iran. Ore Geol. Rev. 128, 103924 (2021).

    Article  Google Scholar 

  99. Stosch, H. G., Romer, R. L., Daliran, F. & Rhede, D. Uranium–lead ages of apatite from iron oxide ores of the Bafq District, east-central Iran. Miner. Deposita 46, 9–21 (2011).

    Article  Google Scholar 

  100. Nayebi, N., Esmaeily, D., Chew, D. M., Lehmann, B. & Modabberi, S. Geochronological and geochemical evidence for multi-stage apatite in the Bafq iron metallogenic belt (central Iran), with implications for the Chadormalu iron-apatite deposit. Ore Geol. Rev. 132, 104054 (2021).

    Article  Google Scholar 

  101. Chen, H., Clark, A. H. & Kyser, T. K. The Marcona magnetite deposit, Ica, south-central Peru: a product of hydrous, iron oxide-rich melts? Econ. Geol. 105, 1441–1456 (2010).

    Article  Google Scholar 

  102. Oyarzún, R., Oyarzún, J., Ménard, J. J. & Lillo, J. The Cretaceous iron belt of northern Chile: role of oceanic plates, a superplume event, and a major shear zone. Miner. Deposita 38, 640–646 (2003).

    Article  Google Scholar 

  103. Knipping, J. L. et al. Trace elements in magnetite from massive iron oxide–apatite deposits indicate a combined formation by igneous and magmatic-hydrothermal processes. Geochim. Cosmochim. Acta 171, 15–38 (2015).

    Article  Google Scholar 

  104. Knipping, J. L. et al. In-situ iron isotope analyses reveal igneous and magmatic-hydrothermal growth of magnetite at the Los Colorados Kiruna-type iron oxide–apatite deposit, Chile. Am. Mineral. 104, 471–484 (2019).

    Article  Google Scholar 

  105. La Cruz, N. L. et al. The geochemistry of apatite from the Los Colorados iron oxide–apatite deposit, Chile: implications for ore genesis. Miner. Deposita 54, 1143–1156 (2019).

    Article  Google Scholar 

  106. Bookstrom, A. A. The magnetite deposits of El Romeral, Chile. Econ. Geol. 72, 1101–1130 (1977).

    Article  Google Scholar 

  107. Rojas, P. et al. New contributions to the understanding of Kiruna-type iron oxide–apatite deposits revealed by magnetite ore and gangue mineral geochemistry at the El Romeral deposit, Chile. Ore Geol. Rev. 93, 413–435 (2018).

    Article  Google Scholar 

  108. Salazar, E. et al. Trace element geochemistry of magnetite from the Cerro Negro Norte iron oxide−apatite deposit, northern Chile. Miner. Deposita 55, 409–428 (2020).

    Article  Google Scholar 

  109. Gelcich, S., Davis, D. W. & Spooner, E. T. C. Testing the apatite-magnetite geochronometer: U-Pb and 40Ar/39Ar geochronology of plutonic rocks, massive magnetite-apatite tabular bodies, and IOCG mineralization in Northern Chile. Geochim. Cosmochim. Acta 69, 3367–3384 (2005).

    Article  Google Scholar 

  110. Palma, G. et al. Halogens, trace element concentrations, and Sr-Nd isotopes in apatite from iron oxide–apatite (IOA) deposits in the Chilean iron belt: evidence for magmatic and hydrothermal stages of mineralization. Geochim. Cosmochim. Acta 246, 515–540 (2019).

    Article  Google Scholar 

  111. Jara, J. J. et al. Episodic construction of the early Andean Cordillera unravelled by zircon petrochronology. Nat. Commun. 12, 4930 (2021).

    Article  Google Scholar 

  112. Naranjo, J. A., Henríquez, F. & Nyström, J. O. Subvolcanic contact metasomatism at El Laco Volcanic Complex, Central Andes. Andean Geol. 37, 110–120 (2010).

    Google Scholar 

  113. Tornos, F., Velasco, F. & Hanchar, J. M. The magmatic to magmatic-hydrothermal evolution of the El Laco deposit (Chile) and its implications for the genesis of magnetite-apatite deposits. Econ. Geol. 112, 1595–1628 (2017).

    Article  Google Scholar 

  114. Xie, Q. et al. New insights for the formation of Kiruna-type iron deposits by immiscible hydrous Fe-P Melt and high-temperature hydrothermal processes: evidence from El Laco deposit. Econ. Geol. 114, 35–46 (2019).

    Article  Google Scholar 

  115. Bain, W. M. et al. Evidence for iron-rich sulfate melt during magnetite(-apatite) mineralization at El Laco, Chile. Geology 49, 1044–1048 (2021).

    Article  Google Scholar 

  116. Ovalle, J. T. et al. Magmatic-hydrothermal evolution of the El Laco iron deposit revealed by trace element geochemistry and high-resolution chemical mapping of magnetite assemblages. Geochim. Cosmochim. Acta https://doi.org/10.1016/j.gca.2022.03.012 (2022).

    Article  Google Scholar 

  117. Broughm, S. G., Hanchar, J. M., Tornos, F., Westhues, A. & Attersley, S. Mineral chemistry of magnetite from magnetite-apatite mineralization and their host rocks: examples from Kiruna, Sweden, and El Laco, Chile. Miner. Deposita 52, 1223–1244 (2017).

    Article  Google Scholar 

  118. Childress, T. et al. Triple oxygen, hydrogen, and iron stable isotope signatures indicate a silicate magma source and magmatic- hydrothermal genesis for magnetite orebodies at El Laco, Chile. Econ. Geol. 115, 1519–1536 (2020).

    Article  Google Scholar 

  119. La Cruz, N. L. et al. The geochemistry of magnetite and apatite from the El Laco iron oxide–apatite deposit, Chile: implications for ore genesis. Econ. Geol. 115, 1461–1491 (2020).

    Article  Google Scholar 

  120. Huang, X. W. & Beaudoin, G. Textures and chemical compositions of magnetite from iron oxide copper-gold (IOCG) and Kiruna-type iron oxide-apatite (IOA) deposits and their implications for ore genesis and magnetite classification schemes. Econ. Geol. 114, 1–74 (2019).

    Article  Google Scholar 

  121. Huang, X. W. et al. Trace element composition of iron oxides from IOCG and IOA deposits: relationship to hydrothermal alteration and deposit subtypes. Miner. Deposita 54, 525–552 (2019).

    Article  Google Scholar 

  122. Bilenker, L. D. et al. Fe-O stable isotope pairs elucidate a high-temperature origin of Chilean iron oxide-apatite deposits. Geochim. Cosmochim. Acta 177, 94–104 (2016).

    Article  Google Scholar 

  123. Troll, V. R. et al. Global Fe–O isotope correlation reveals magmatic origin of Kiruna-type apatite-iron-oxide ores. Nat. Commun. 10, 1712 (2019).

    Article  Google Scholar 

  124. Ghiorso, M. S. & Sack, O. Fe–Ti oxide geothermometry: thermodynamic formulation and the estimation of intensive variables in silicic magmas. Contrib. Mineral. Petrol. 108, 485–510 (1991).

    Article  Google Scholar 

  125. Dare, S. A. et al. Trace elements in magnetite as petrogenetic indicators. Miner. Deposita 49, 785–796 (2014).

    Article  Google Scholar 

  126. Sievwright, R. H., Wilkinson, J. J., O’Neill, H. S. C. & Berry, A. J. Thermodynamic controls on element partitioning between titanomagnetite and andesitic–dacitic silicate melts. Contrib. Mineral. Petrol. 172, 62 (2017).

    Article  Google Scholar 

  127. Sievwright, R. H., O’Neill, H. S. C., Tolley, J., Wilkinson, J. J. & Berry, A. J. Difusion and partition coefcients of minor and trace elements in magnetite as a function of oxygen fugacity at 1150 °C. Contrib. Mineral. Petrol. 175, 40 (2020).

    Article  Google Scholar 

  128. Dupuis, C. & Beaudoin, G. Discriminant diagrams for iron oxide trace element fingerprinting of mineral deposit types. Miner. Deposita 46, 319–335 (2011).

    Article  Google Scholar 

  129. Nadoll, P., Mauk, J. L., Hayes, T. S., Koenig, A. E. & Box, S. E. Geochemistry of magnetite from hydrothermal ore deposits and host rocks of the Mesoproterozoic Belt Supergroup, United States. Econ. Geol. 107, 1275–1292 (2012).

    Article  Google Scholar 

  130. Nadoll, P., Angerer, T., Mauk, J. L., French, D. & Walshe, J. The chemistry of hydrothermal magnetite: a review. Ore Geol. Rev. 61, 1–32 (2014).

    Article  Google Scholar 

  131. Nadoll, P., Mauk, J. L., Leveille, R. A. & Koenig, A. E. Geochemistry of magnetite from porphyry Cu and skarn deposits in the southwestern United States. Miner. Deposita 50, 493–515 (2015).

    Article  Google Scholar 

  132. Deditius, A. P. et al. Nanogeochemistry of hydrothermal magnetite. Contrib. Miner. Petrol. 173, 46 (2018).

    Article  Google Scholar 

  133. Canil, D. & Lacourse, T. Geothermometry using minor and trace elements in igneous and hydrothermal magnetite. Chem. Geol. 541, 119576 (2020).

    Article  Google Scholar 

  134. Verdugo-Ihl, M. R. et al. Nanomineralogy of hydrothermal magnetite from Acropolis, South Australia: genetic implications for iron-oxide copper gold mineralization. Am. Mineral. 106, 1273–1293 (2021).

    Article  Google Scholar 

  135. Huang, X. W. & Beaudoin, G. Nanoinclusions in zoned magnetite from the Sossego IOCG deposit, Carajás, Brazil: implication for mineral zoning and magnetite origin discrimination. Ore Geol. Rev. 139, 104453.

  136. Hu, H. et al. Reequilibration processes in magnetite from iron skarn deposits. Econ. Geol. 111, 1–8 (2015).

    Article  Google Scholar 

  137. Wen, G. et al. Hydrothermal reequilibration of igneous magnetite in altered granitic plutons and its implications for magnetite classification schemes: insights from the Handan-Xingtai iron district, North China Craton. Geochim. Cosmochim. Acta 213, 255–270 (2017).

    Article  Google Scholar 

  138. Yin, S., Ma, C. & Robinson, P. T. Textures and high field strength elements in hydrothermal magnetite from a skarn system: Implications for coupled dissolution-reprecipitation reactions. Am. Mineral. 102, 1045–1056 (2017).

    Google Scholar 

  139. Liu, Y. et al. In-situ LA-ICP-MS trace element analysis of magnetite from Mesozoic iron oxide apatite (IOA) deposits in the Luzong volcanic basin, eastern China. J. Asian Earth Sci. 166, 233–246 (2018).

    Article  Google Scholar 

  140. Krolop, P. et al. Trace element geochemistry of iron oxides from the Per Geijer apatite iron ores in the Kiruna district, northern Sweden: implications for ore genesis. EGU21-1987 (EGU General Assembly, 2021).

  141. Majidi, S. A. et al. Employing geochemistry and geochronology to unravel genesis and tectonic setting of iron oxide-apatite deposits of the Bafq-Saghand metallogenic belt, Central Iran. Int. J. Earth. Sci. 110, 127–164 (2021).

    Article  Google Scholar 

  142. Sidder, G. B. et al. Mineralogic and fluid-inclusion studies of the Pea Ridge iron-rare-earth-element deposit, southeast Missouri. USGS Bull. 2039, 205–216 (1993).

    Google Scholar 

  143. Sheets, S. A. Fluid Inclusion Study of the El Laco Magnetite Deposits, Chile. MSc thesis, 94 (Dartmouth College, Hanover, 1997).

  144. Broman, C., Nyström, J. O., Henríquez, F. & Elfman, M. Fluid inclusions in magnetite-apatite ore from a cooling magmatic system at El Laco, Chile. GFF 121, 253–267 (1999).

    Article  Google Scholar 

  145. Jami, M., Dunlop, A. C. & Cohen, D. R. Fluid inclusion and stable isotope study of Esfordi apatite-magnetite deposit, Central Iran. Econ. Geol. 102, 1111–1125 (2007).

    Article  Google Scholar 

  146. Gleeson, S. A. & Smith, M. P. The sources and evolution of mineralizing fluids in iron oxide-copper-gold systems, Norrbotten, Sweden: constraints from Br/Cl ratios and stable Cl isotopes of fluid inclusion leachates. Geochim. Cosmochim. Acta 73, 5658–5672 (2009).

    Article  Google Scholar 

  147. Martinsson, O., Billström, K., Broman, C., Weihed, P. & Wanhainen, C. Metallogeny of the Northern Norrbotten Ore Province, northern Fennoscandian Shield with emphasis on IOCG and apatite-iron ore deposits. Ore Geol. Rev. 78, 447–492 (2016).

    Article  Google Scholar 

  148. Bain, W. M. et al. A fundamental role of carbonate–sulfate melts in the formation of iron oxide–apatite deposits. Nat. Geosci. 13, 751–757 (2020).

    Article  Google Scholar 

  149. Harlov, D. E. et al. Apatite–monazite relations in the Kiirunavaara magnetite–apatite ore, northern Sweden. Chem. Geol. 191, 47–72 (2002).

    Article  Google Scholar 

  150. Xie, Q. H. et al. Magnesium isotopic composition of continental arc andesites and the implications: A case study from the El Laco volcanic complex, Chile. Lithos 318–319, 91–103 (2018).

    Article  Google Scholar 

  151. Lledo, H. L. & Jenkins, D. M. Experimental investigation of the upper thermal stability of Mg-rich actinolite; implications for Kiruna-type iron deposits. J. Petrol. 49, 225–238 (2008).

    Article  Google Scholar 

  152. Nyström, J. O. et al. Oxygen isotope composition of magnetite in iron ores of the Kiruna type in Chile and Sweden. GFF 130, 177–188 (2008).

    Article  Google Scholar 

  153. Johnson, C. A., Day, W. C. & Rye, R. O. Oxygen, hydrogen, sulfur, and carbon isotopes in the Pea Ridge magnetite-apatite deposit, southeast Missouri, and sulfur isotope comparisons to other iron deposits in the region. Econ. Geol. 111, 2017–2032 (2016).

    Article  Google Scholar 

  154. Deymar, S., Yazdi, M., Rezvanianzadeh, M. R. & Behzadi, M. Alkali metasomatism as a process for Ti–REE–Y–U–Th mineralization in the Saghand Anomaly 5, Central Iran: insights from geochemical, mineralogical, and stable isotope data. Ore Geol. Rev. 93, 308–336 (2018).

    Article  Google Scholar 

  155. Xie, Q. et al. Constraints of Fe-O isotopes on the origin of magnetite in the El Laco Kiruna-type iron deposit, Chile. Ore Geol. Rev. 130, 103967 (2021).

    Article  Google Scholar 

  156. McCafferty, A. E., Phillips, J. D., Hofstra, A. H. & Day, W. C. Crustal architecture beneath the southern midcontinent (USA) and controls on Mesoproterozoic iron-oxide mineralization from 3D geophysical models. Ore Geol. Rev. 111, 102966 (2019).

    Article  Google Scholar 

  157. Shah, A. K., Taylor, R. D., Walsh, G. & Phillips, J. Integrated geophysical imaging of rare-earth-element-bearing iron oxide-apatite deposits in the eastern Adirondack Highlands, New York. Geophysics 86, B37–B54 (2021).

    Article  Google Scholar 

  158. Hildebrand, R. S. Kiruna-type deposits: their origin and relationship to intermediate subvolcanic plutons in the Great Bear Magmatic Zone, Northwest Canada. Econ. Geol. 81, 640–659 (1986).

    Article  Google Scholar 

  159. Camprubí, A. et al. Geochronology of Mexican mineral deposits. VII: The Peña Colorada magmatic-hydrothermal iron oxide deposits (IOCG ‘clan’), Colima. Bol. Soc. Geol. Mex. 70, 633–674 (2018).

    Article  Google Scholar 

  160. Heimann, A., Beard, B. L. & Johnson, C. M. The role of volatile exsolution and sub-solidus fluid/rock interactions in producing high 56Fe/54Fe ratios in siliceous igneous rocks. Geochim. Cosmochim. Acta 72, 4379–4396 (2008).

    Article  Google Scholar 

  161. Bindeman, I. Oxygen isotopes in mantle and crustal magmas as revealed by single crystal analysis. Rev. Mineral. Geochem. 69, 445–478 (2008).

    Article  Google Scholar 

  162. Weis, F. Oxygen and Iron Isotope Systematics of the Grängesberg Mining District (GMD), Central Sweden. MSc thesis, 77 (Uppsala Univ., 2013).

  163. Tornos, F., Hanchar, J. M., Munizaga, R., Velasco, F. & Galindo, C. The role of the subducting slab and melt crystallization in the formation of magnetite-(apatite) systems, Coastal Cordillera of Chile. Miner. Deposita 56, 253–278 (2021).

    Article  Google Scholar 

  164. Weis, F. et al. Absence of hydrothermal oxygen isotope variations in host rocks supports magmatic origin of the giant Grängesberg iron oxide–apatite (IOA) deposit, Central Sweden. Int. J. Earth. Sci. https://doi.org/10.1007/s00531-021-02122-9 (2021).

    Article  Google Scholar 

  165. Lindsley, D. H. & Epler, N. Do Fe-Ti-oxide magmas exist? Probably not! Am. Mineral. 102, 2157–2169 (2017).

    Article  Google Scholar 

  166. Hurwitz, S. & Navon, O. Bubble nucleation in rhyolitic melts: experiments at high pressure, temperature, and water content. Earth Planet. Sci. Let. 122, 267–280 (1994).

    Article  Google Scholar 

  167. Gardner, J. E. & Denis, M. H. 2004, Heterogeneous bubble nucleation on Fe-Ti oxide crystals in high-silica rhyolitic melts. Geochim. Cosmochim. Acta 68, 3587–3597 (2004).

    Article  Google Scholar 

  168. Edmonds, M., Brett, A., Herd, R. A., Humphreys, M. C. S. & Woods, A. Magnetite-bubble aggregates at mixing interfaces in andesite magma bodies. Geol. Lond. Spec. Publ. 410, 95–121 (2014).

    Article  Google Scholar 

  169. Gualda, G. A. R. & Anderson, A. T. Magnetite scavenging and the buoyancy of bubbles in magmas. Part 1: Discovery of a pre-eruptive bubble in Bishop rhyolite. Contrib. Mineral. Petrol. 154, 733–742 (2007).

    Article  Google Scholar 

  170. Gardner, J. E. Heterogeneous bubble nucleation in highly viscous silicate melts during instantaneous decompression from high pressure. Chem. Geol. 236, 1–12 (2007).

    Article  Google Scholar 

  171. Gualda, G. A. R. & Ghiorso, M. S. Magnetite scavenging and the buoyancy of bubbles in magmas. Part 2: Energetics of crystal-bubble attachment in magmas. Contrib. Miner. Petrol. 154, 479–490 (2007).

    Article  Google Scholar 

  172. Cluzel, N., Laporte, D. & Provost, A. Kinetics of heterogeneous bubble nucleation in rhyolitic melts: implications for the number density of bubbles in volcanic conduits and for pumice textures. Contrib. Miner. Petrol. 156, 745–763 (2008).

    Article  Google Scholar 

  173. Gardner, J. E. & Ketcham, R. A. Bubble nucleation in rhyolite and dacite melts: temperature dependence of surface tension. Contrib. Miner. Petrol. 162, 929–943 (2011).

    Article  Google Scholar 

  174. Knipping, J. L., Webster, J. D., Simon, A. C. & Holtz, F. Accumulation of magnetite by flotation on bubbles during decompression of silicate magma. Sci. Rep. 9, 3852 (2019).

    Article  Google Scholar 

  175. Plêse, P. et al. Production and detachment of oxide crystal shells on bubble walls during experimental vesiculation of andesitic magmas. Contrib. Miner. Petrol. 174, 21 (2019).

    Article  Google Scholar 

  176. Edmonds, M. Flotation of magmatic minerals. Research focus. Geology 43, 655–656 (2015).

    Article  Google Scholar 

  177. Townsend, M. & Huber, C. A critical magma chamber size for volcanic eruptions. Geology 48, 431–435 (2020).

    Article  Google Scholar 

  178. Chou, I. M. & Eugster, H. P. Solubility of magnetite in supercritical chloride solutions. Am. J. Sci. 277, 1296–1314 (1977).

    Article  Google Scholar 

  179. Heinrich, C. A., Ryan, C. G., Mernagh, T. P. & Eadington, P. J. Segregation of ore metals between magmatic brine and vapor — a fluid inclusion study using PIXE microanalysis. Econ. Geol. 87, 1566–1583 (1992).

    Article  Google Scholar 

  180. Audétat, A., Günther, D. & Heinrich, C. A. Magmatic-hydrothermal evolution in a fractionating granite: a micro-chemical study of the Sn-W-F-mineralized mole granite (Australia). Geochim. Cosmochim. Acta 64, 3373–3393 (2000).

    Article  Google Scholar 

  181. Simon, A. C., Pettke, T., Candela, P. A., Piccoli, P. M. & Heinrich, A. H. Magnetite solubility and iron transport in magmatic-hydrothermal environments. Geochim. Cosmochim. Acta 68, 4905–4914 (2004).

    Article  Google Scholar 

  182. Williams-Jones, A. E. & Heinrich, C. A. Vapor transport of metals and the formation of magmatic-hydrothermal ore deposits. Econ. Geol. 100, 1287–1312 (2005).

    Article  Google Scholar 

  183. Matveev, S. & Ballhaus, C. Role of water in the origin of podiform chromitite deposits. Earth Planet. Sci. Lett. 203, 235–243 (2002).

    Article  Google Scholar 

  184. Martel, C., Pichavant, M., Holtz, F. & Scaillet, B. Effects of fO2 and H2O on andesite phase relations between 2 and 4 kbar. J. Geophys. Res. 104, 29453–29470 (1999).

    Article  Google Scholar 

  185. Mungall, J. E., Brenan, J. M., Godel, B., Barnes, S. & Gaillard, F. Transport of metals and sulphur in magmas by flotation of sulphide melt on vapour bubbles. Nat. Geosci. 8, 216–219 (2015).

    Article  Google Scholar 

  186. Cashman, C. V., Sparks, R. J. S. & Blundy, J. D. Vertically extensive and unstable magmatic systems: a unified view of igneous processes. Science 355, 6331 (2017).

    Article  Google Scholar 

  187. Matthews, S. J., Sparks, R. S. J. & Gardeweg, M. C. The Piedras Grandes–Soncor Eruptions, Lascar Volcano, Chile; evolution of a zoned magma chamber in the Central Andean upper crust. J. Petrol. 40, 1891–1919 (1999).

    Article  Google Scholar 

  188. Bell, A. & Simon, A. C. Evidence for the alteration of the Fe3+/ΣFe of silicate melt caused by the degassing of chlorine-bearing aqueous volatiles. Geology 39, 499–502 (2011).

    Article  Google Scholar 

  189. Edmonds, M. & Wallace, P. Volatiles and exsolved vapor in volcanic systems. Elements 13, 29–34 (2017).

    Article  Google Scholar 

  190. Wallace, P. J., Anderson, A. T. & Davis, A. M. Gradients in H2O, CO2, and exsolved gas in a large-volume silicic magma system: interpreting the record preserved in melt inclusions from the Bishop Tuff. J. Geophys. Res. Sol. Earth 104, 20097–20122 (1999).

    Article  Google Scholar 

  191. Walter, T. R. & Troll, V. R. Formation of caldera periphery faults: an experimental study. Bull. Volcanol. 63, 191 (2001).

    Article  Google Scholar 

  192. Seward, T. M., Williams-Jones, A. E. & Migdisov, A. A. in Treatise of Geochemistry Vol. 13 (eds. Holland, H. & Turekian, K.) 29–57 (Elsevier, 2014).

  193. Dolejs, D. & Zajacz, Z. in The Role of Halogens In Terrestrial and Extraterrestrial Geochemical Processes: Surface, Crust, and Mantle (eds. Harlov, D. E. & Aranovich, L.) 431–543 (Springer, 2018).

  194. Williams-Jones, A. & Migdisov, A. Experimental constraints on the transport and deposition of metals in ore-forming hydrothermal systems. Soc. Econ. Geol. Spec. Publ. 18, 77–96 (2014).

    Google Scholar 

  195. Yao, Z., Mungall, J. E. & Jenkins, M. C. The Rustenburg Layered Suite formed as a stack of mush with transient magma chambers. Nat. Commun. 12, 505 (2021).

    Article  Google Scholar 

  196. Yao, Z. & Mungall, J. E. Magnetite layer formation in the Bushveld Complex of South Africa. Nat. Commun. 13, 416 (2022).

    Article  Google Scholar 

  197. Richards, J. P. et al. Contrasting tectonic settings and sulfur contents of magmas associated with cretaceous porphyry Cu ± Mo ± Au and intrusion-related iron oxide Cu-Au deposits in Northern Chile. Econ. Geol. 112, 295–318 (2017).

    Article  Google Scholar 

  198. Park, J. W., Campbell, I. H., Chiaradia, M., Hao, H. & Lee, C.-T. Crustal magmatic controls on the formation of porphyry copper deposits. Nat. Rev. Earth Environ. 2, 542–557 (2021).

    Article  Google Scholar 

  199. Bauer, T. E., Andersson, J. B. H., Sarlus, Z., Lund, C. & Kearney, T. Structural controls on the setting, shape, and hydrothermal alter- ation of the Malmberget iron oxide-apatite deposit, Northern Sweden. Econ. Geol. 113, 377–395 (2018).

    Article  Google Scholar 

  200. Andersson, J. B. H., Bauer, T. E. & Lynch, E. P. Evolution of structures and hydrothermal alteration in a Palaeoproterozoic supracrustal belt: constraining paired deformation-fluid flow events in an Fe and Cu-Au prospective terrain in northern Sweden. Solid. Earth 11, 547–578 (2020).

    Article  Google Scholar 

  201. Ridolfi, F. & Renzulli, A. Calcic amphiboles in calc-alkaline and alkaline magmas: thermobarometric and chemometric empirical equations valid up to 1,130 °C and 2.2 GPa. Contrib. Miner. Petrol. 163, 877–895 (2012).

    Article  Google Scholar 

  202. Mutch, E. J. F., Blundy, J. D., Tattitch, B. C., Cooper, F. J. & Brooker, R. A. An experimental study of amphibole stability in low-pressure granitic magmas and a revised Al-in-hornblende geobarometer. Contrib. Mineral. Petrol. 171, 85 (2016).

    Article  Google Scholar 

  203. Chelle-Michou, C., Rottier, B., Caricchi, L. & Simpson, G. Tempo of magma degassing and the genesis of porphyry copper deposits. Sci. Rep. 7, 40566 (2017).

    Article  Google Scholar 

  204. Chiaradia, M. & Caricchi, L. Supergiant porphyry copper deposits are failed large eruptions. Commun. Earth Environ. 3, 107 (2022).

    Article  Google Scholar 

  205. Audétat, A. The metal content of magmatic-hydrothermal fluids and its relationship to mineralization potential. Econ. Geol. 114, 1033–1056 (2019).

    Article  Google Scholar 

  206. Ortelli, M., Kouzmanov, K., Wälle, M. & Casanova, V. Fluid inclusion studies in opaque ore minerals: I. Trace element content and physical properties of ore minerals controlling textural features in transmitted near-infrared light microscopy. Econ. Geol. 113, 1845–1860 (2018).

    Article  Google Scholar 

  207. Casanova, V. et al. Fluid inclusion studies in opaque ore minerals: II. A comparative study of syngenetic synthetic fluid inclusions hosted in quartz and opaque minerals. Econ. Geol. 113, 1861–1883 (2018).

    Article  Google Scholar 

  208. Storey, C. R. & Smith, M. P. Metal source and tectonic setting of iron oxide-copper-gold (IOCG) deposits: evidence from an in situ Nd isotope study of titanite from Norrbotten, Sweden. Ore Geol. Rev. 81, 1287–1302 (2017).

    Article  Google Scholar 

  209. del Real, I., Thompson, J. F. H. & Carriedo, J. Lithological and structural controls on the genesis of the Candelaria-Punta del Cobre iron oxide copper gold district, Northern Chile. Ore Geol. Rev. 102, 106–153 (2018).

    Article  Google Scholar 

  210. Hu, H. et al. A genetic link between iron oxide-apatite and iron skarn mineralization in the Jinniu volcanic basin, Daye district, eastern China: evidence from magnetite geochemistry and multi-mineral U-Pb geochronology. GSA Bull. 132, 899–917 (2019).

    Article  Google Scholar 

  211. Ehrig, K. et al. Staged formation of the supergiant Olympic Dam uranium deposit, Australia. Geology 49, 1312–1316 (2021).

    Article  Google Scholar 

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Acknowledgements

Funding to M.R., F.B. and G.P. was provided by Millennium Science Initiative through Millennium Nucleus for Metal Tracing along Subduction Grant NC130065. Additional support was provided by FONDAP project 15090013 “Centro de Excelencia en Geotermia de Los Andes, CEGA”, and FONDECYT grant #1190105.

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Authors and Affiliations

  1. Department of Geology and Andean Geothermal Center of Excellence (CEGA), FCFM, Universidad de Chile, Santiago, Chile

    Martin Reich & Fernando Barra

  2. Millennium Nucleus for Metal Tracing Along Subduction, FCFM, Universidad de Chile, Santiago, Chile

    Martin Reich & Fernando Barra

  3. Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI, USA

    Adam C. Simon

  4. Escuela de Geología, Universidad Mayor, Santiago, Chile

    Gisella Palma

  5. State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Beijing, China

    Tong Hou

  6. Institut für Mineralogie, Leibniz Universtät Hannover, Hannover, Germany

    Tong Hou

  7. Department of Geosciences, College of Sciences and Mathematics, Auburn University, Auburn, AL, USA

    Laura D. Bilenker

Authors
  1. Martin Reich
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  2. Adam C. Simon
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Contributions

All of the authors contributed to the discussion of the content as a team. M.R. wrote the paper with contributions from A.C.S., F.B., T.H., G.P. and L.D.B. Compilation of the data sets and preparation of figures was carried out by G.P., M.R. and T.H.

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Correspondence to Martin Reich.

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Glossary

Massive magnetite ore

Mineral assemblage composed of ⪅90% magnetite [Fe3O4], with variable amounts of apatite, actinolite and/or pyroxene.

Apatite

Group of common phosphate minerals [Ca5(PO4)3(F, Cl, OH)] including fluorapatite, chlorapatite and hydroxyapatite.

Actinolite

Calcium magnesium iron silicate mineral of the amphibole group [Ca2(Mg4.5–2.5Fe0.5–2.5)Si8O22(OH)2].

Pyroxene

Most important group of rock-forming ferromagnesian silicates, which includes the clinopyroxene diopside [CaMgSi2O6].

Stockworks

Structurally controlled or randomly oriented sets of veins that form a three-dimensional network.

Stratabound

An ore body confined to a single stratigraphic level or unit.

Pegmatite

Intrusive igneous rock occurring as dykes, veins or lenses, and consisting almost entirely of centimetre-sized crystals.

Silicate liquid immiscibility

Process leading to formation of mixtures of distinct iron-rich and silica-rich melts from one parental silicate magma.

Metasomatic replacement

Fluid-driven replacement process of one mineral or a mineral assemblage by another of different composition, while the rock remains solid.

Arc settings

Tectonic environments where one oceanic plate subducts beneath another oceanic plate, or under a continental plate.

Liquidus phase

A crystalline phase that forms first on cooling from a silicate melt, at or below its liquidus temperature.

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Reich, M., Simon, A.C., Barra, F. et al. Formation of iron oxide–apatite deposits. Nat Rev Earth Environ 3, 758–775 (2022). https://doi.org/10.1038/s43017-022-00335-3

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