Immiscible hydrous Fe-Ca-P melt and the origin of iron oxide-apatite ore deposits

[en] The origin of iron oxide-apatite deposits is controversial. Silicate liquid immiscibility and separation of an iron-rich melt has been invoked, but Fe-Ca-P-rich and Si-poor melts similar in composition to the ore have never been observed in natural or synthetic magmatic systems. Here we report experiments on intermediate magmas that develop liquid immiscibility at 100 MPa, 1000-1040°C, and oxygen fugacity conditions (fO2) of ΔFMQ = 0.5-3.3 (FMQ = fayalite-magnetite-quartz equilibrium). Some of the immiscible melts are highly enriched in iron and phosphorous ± calcium, and strongly depleted in silicon (<5 wt.% SiO2). These Si-poor melts are in equilibrium with a rhyolitic conjugate and are produced under oxidized conditions (∼FMQ + 3.3), high water activity (aH2O ≥ 0.7), and in fluorine-bearing systems (1 wt.%). Our results show that increasing aH2O and fO2 enlarges the two-liquid field thus allowing the Fe-Ca-P melt to separate easily from host silicic magma and produce iron oxide-apatite ores. © 2018 The Author(s).

Disciplines :

Earth sciences & physical geography

Author, co-author :

Hou, T.; Institute of Mineralogy, Leibniz Universtät Hannover, Hannover, 30167, Germany, State Key Laboratory of Geological Process and Mineral Resources, China University of Geosciences, Beijing, 100083, China

Charlier, Bernard ; Université de Liège - ULiège > Département de géologie > Pétrologie, géochimie endogènes et pétrophysique

Holtz, F.; Institute of Mineralogy, Leibniz Universtät Hannover, Hannover, 30167, Germany

Veksler, I.; GFZ German Research Center for Geosciences, Telegrafenberg, Potsdam, 14473, Germany, Geological Department, Perm State University, Bukireva 15, Perm, 614990, Russian Federation

Zhang, Z.; State Key Laboratory of Geological Process and Mineral Resources, China University of Geosciences, Beijing, 100083, China

Thomas, R.; GFZ German Research Center for Geosciences, Telegrafenberg, Potsdam, 14473, Germany

Namur, Olivier ; Université de Liège - ULiège > Département de géologie > Pétrologie, géochimie endogènes et pétrophysique

Language :

English

Title :

Immiscible hydrous Fe-Ca-P melt and the origin of iron oxide-apatite ore deposits

Publication date :

2018

Journal title :

Nature Communications

eISSN :

2041-1723

Publisher :

Nature Publishing Group, United Kingdom

Volume :

Issue :

Peer reviewed :

Peer Reviewed verified by ORBi

Available on ORBi :

since 15 October 2019

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Bibliography

Frietsch, R. On the magmatic origin of iron ores of the Kiruna type. Econ. Geol. 73, 478-485 (1978).
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).
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).
Gleason, J. D., Marikos, M. A., Barton, M. D. & Johnson, D. A. Neodymium isotopic study of rare earth element sources and mobility in hydrothermal Fe oxide (Fe-P-REE) systems. Geochim. Cosmochim. Acta 64, 1059-1068 (2000).
Naslund, H. R., Henriquez, 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 (Porter Geoscience Consultancy Publishing, Adelaide, 2002).
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).
Chen, H., Clark, A. H. & Kyser, T. K. The Marcona magnetite deposit, Ica, South-Central Peru: a product of hydrous, iron oxide-rich liquids? Econ. Geol. 105, 1441-1456 (2010).
Jonsson, E. et al. Magmatic origin of giant 'Kiruna-type' apatite-iron-oxide ores in Central Sweden. Sci. Rep. 3, 1644 (2013).
Dare, S. A., 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. Depos. 50, 607-617 (2015).
Knipping, J. L. et al. Giant Kiruna-type deposits form by efficient flotation of magmatic magnetite suspensions. Geology 43, 591-594 (2015).
Tornos, F., Velasco, F. & Hanchar, J. M. Iron-rich liquids, magmatic magnetite, and superheated hydrothermal systems: the El Laco deposit, Chile. Geology 44, 427-430 (2016).
Nyström, J. O., Henríquez, F., Naranjo, J. A. & Nasuland, H. R. Magnetite spherules in pyroclastic iron ore at El Laco, Chile. Am. Miner. 101, 587-595 (2016).
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).
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).
Lindsley, D. & Epler, N. Do Fe-Ti-oxide magmas exist? Probably not! Am. Miner. 102, 2157-2169 (2017).
Lester, G. W., Clark, A. H., Kyser, T. K. & Naslund, H. R. Experiments on liquid immiscibility in silicate liquids with H2O, P, S, F and Cl: implications for natural magmas. Contrib. Miner. Petrol. 166, 329-349 (2013).
Philpotts, A. R. Compositions of immiscible liquids in volcanic rocks. Contrib. Mineral. Petrol. 80, 201-218 (1982).
Charlier, B., Namur, O. & Grove, T. L. Compositional and kinetic controls on liquid immiscibility in ferrobasalt-rhyolite volcanic and plutonic series. Geochim. Cosmochim. Acta 113, 79-93 (2013).
Charlier, B. & Grove, T. L. Experiments on liquid immiscibility along tholeiitic liquid lines of descent. Contrib. Mineral. Petrol. 164, 27-44 (2012).
Bogaerts, M. & Schmidt, M. W. Experiments on silicate liquid immiscibility in the system Fe2SiO4-KAlSi3O8-SiO2-CaO-MgO-TiO2-P2O5 and implications for natural magmas. Contrib. Mineral. Petrol. 152, 257-274 (2006).
Ryerson, F. J. & Hess, P. C. Implications of liquid-liquid distribution coefficients to mineral-liquid partitioning. Geochim. Cosmochim. Acta 42, 921-932 (1978).
Longhi, J. Silicate liquid immiscibility in isothermal crystallisation experiments. Proc. Lunar Planet. Sci. Conf. 20, 13-24 (1990).
Hess, P. C., Rutherford, M. J., Guillemette, R. N., Ryerson, F. J. & Tuchfeld, H. A. Residual products of fractional crystallisation of lunar magmas-an experimental study. Proc. Lunar Planet. Sci. Conf. 6, 895-909 (1975).
Rutherford, M. J., Hess, P. C. & Daniel, G. H. Experimental liquid line of descent and liquid immiscibility for basalt 70017. Proc. Lunar Planet. Sci. Conf. 5, 569-583 (1974).
Dixon, S. & Rutherford, M. J. Plagiogranites as late-stage immiscible liquids in ophiolite and mid-ocean ridge suites: an experimental study. Earth. Planet. Sci. Lett. 45, 45-60 (1979).
Philpotts, A. R. & Doyle, C. D. Effect of magma oxidation state on the extent of silicate liquid immiscibility in a tholeiitic basalt. Am. J. Sci. 283, 967-986 (1983).
Kamenetsky, V. S. et al. Magma chamber-scale liquid immiscibility in the Siberian Traps represented by liquid pools in native iron. Geology 41, 1091-1094 (2013).
Hou, T. et al. Experimental study of liquid immiscibility in the Kiruna-type Vergenoeg iron-fluorine deposit, South Africa. Geochim. Cosmochim. Acta 203, 303-322 (2017).
Namur, O., Charlier, B. & Holness, M. B. Dual origin of Fe-Ti-P gabbros by immiscibility and fractional crystallisation of evolved tholeiitic basalts in the Sept Iles layered intrusion. Lithos 154, 100-114 (2012).
Fischer, L. A. et al. Immiscible iron-and silica-rich liquids in the upper zone of the Bushveld complex. Earth. Planet. Sci. Lett. 443, 108-117 (2016).
Visser, W. & Koster van Groos, A. F. Effect of P2O5 and TiO2 on liquid-liquid equilibria in the system K2O-FeO-Al2O3-SiO2. Am. J. Sci. 279, 970-988 (1979).
Clark, A. H. & Kontak, D. J. Fe-Ti-P oxide melts generated through magma mixing in the Antauta subvolcanic center, Peru: implications for the origin of nelsonite and iron oxide-dominated hydrothermal deposits. Econ. Geol. 99, 377-395 (2004).
Lyons, J. I. Volcanogenic iron oxide deposits, Cerro de Mercado and vicinity, Durango. Econ. Geol. 83, 1886-1906 (1988).
Eslamizadeh, A. Petrology and geochemistry of early Cambrian volcanic rocks hosting the Kiruna-type iron ore in Anomaly 10 of Sechahun, Central Iran. J. Sci. Islamic Repub. Iran. 28, 21-35 (2016).
Jiang, Z. et al. Geology, geochemistry, and geochronology of the zhibo iron deposit in the western Tianshan, NW China: constraints on metallogenesis and tectonic setting. Ore Geol. Rev. 57, 406-424 (2014).
Jiang, Z. et al. Geochemistry and zircon U-Pb age of volcanic rocks from the chagangnuoer and zhibo iron deposits, western Tianshan, and their geological significance. Acta Petrol. Sin. 28, 2074-2088 (2012).
Mathez, E. A., Van Tongeren, J. A. & Schweitzer, J. On the relationships between the Bushveld complex and its felsic roof rocks, part 1: petrogenesis of Rooiberg and related felsites. Contrib. Miner. Petrol. 166, 435-449 (2013).
Zajacz, Z. The effect of melt composition on the partitioning of oxidized sulfur between silicate melts and magmatic volatiles. Geochim. Cosmochim. Acta 158, 223-244 (2015).
Wilke, M. Fe in magma-an overview. Ann. Geophys. 48, 609-617 (2005).
Filiberto, J. et al. Effect of fluorine on near-liquidus phase equilibria of an Fe-Mg rich basalt. Chem. Geol. 312-313, 118-126 (2012).
Lukkari, S. & Holtz, F. Phase relations of a F-enriched peraluminous granite: an experimental study of the Kymi topaz granite stock, southern Finland. Contrib. Miner. Petrol. 153, 273-288 (2007).
Kelley, K. A. & Cottrell, E. Water and the oxidation state of subduction zone magmas. Science 325, 605-607 (2009).
Williams, P. et al. in Economic Geology: One Hundredth Anniversary Volume (eds Hedenquist, J. W., et al.) 371-406 (Society of Economic Geologists, Littleton, 2005).
Hitzman, M., Oreskes, N. & Einaudi, M. Geological characteristics and tectonic setting of proterozoic iron oxide (Cu-U-Au-REE) deposits. Precam. Res. 58, 241-287 (1992).
Carmichael, I. S. E. The redox states of basic and silicic magmas: a reflection of their source regions? Contrib. Mineral. Petrol. 106, 129-141 (1991).
Tornos, F., Velasco, F. & Hanchar, J. M. The magmatic to magmatichydrothermal evolution of the El Laco deposit (Chile) and its implications for the genesis of magnetite-apatite deposits. Econ. Geol. 112, 1595-1628 (2017).
Burgisser, A. & Scaillet, B. Redox evolution of a degassing magma rising to the surface. Nature 445, 194-205 (2007).
Bell, A. S. & Simon, A. Experimental 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).
Moussallam, Y. et al. The impact of degassing on the oxidation state of basaltic magmas: a case study of Kīlauea volcano. Earth. Planet. Sci. Lett. 450, 317-325 (2016).
Berndt, J. et al. A combined rapid quench and H2 membrane setup for internally heated pressure vessels: description and application for water solubility in basaltic liquids. Am. Mineral. 87, 1717-1726 (2002).
Taylor, J. R., Wall, V. J. & Pownceby, M. I. The calibration and application of accurate redox sensors. Am. Miner. 77, 284-295 (1992).
Huebner, J. S. & Sato, M. The oxygen fugacity-temperature relationships of manganese and nickel oxide buffers. Am. Miner. 55, 934-952 (1970).
Botcharnikov, R. E., Koepke, J., Holtz, F., McCammon, C. & Wilke, M. The effect of water activity on the oxidation and structural state of Fe in a ferrobasaltic liquid. Geochim. Cosmochim. Acta 69, 5071-5085 (2005).
Botcharnikov, R. E., Almeev, R. R., Koepke, J. & Holtz, F. Phase relations and liquid lines of descent in hydrous ferrobasalt-implications for the Skaergaard intrusion and Columbia river flood basalts. J. Petrol. 49, 1687-1727 (2008).
Burnham, C. W. in Volatiles in Magmas.Reviews in Mineralogy Vol. 30 (eds Carroll, M. R. & Holloway, J. R.) 123-130 (Mineralogical Society of America, 1994).
Almeev, R. R. et al. High-temperature, low-H2O silicic magmas of the yellowstone hotspot: an experimental study of rhyolite from the Bruneau-Jarbidge Eruptive Center, Central Snake River Plain, USA. J. Petrol. 53, 1837-1866 (2012).
Schwab, R. G. & Küstner, D. Die gleichgewichtsfugazitäten technologisch und petrologisch wichtiger sauerstoffpuffer. Neues Jahrb. für Mineral. Abh. 140, 111-142 (1981).
Zhang, C. et al. A practical method for accurate measurement of trace level fluorine in Mg-and Fe-bearing mineral and glass using electron probe microanalysis. Geostand. Geoanal. Res. 40, 351-363 (2016).
Thomas, R. Determination of water contents of granite liquid inclusions by confocal laser Raman microprobe spectroscopy. Am. Mineral. 85, 868-872 (2000).
Thomas, R., Kamenetsky, V. S. & Davidson, P. Laser Raman spectroscopy measurements of water in unexposed glass inclusions. Am. Mineral. 91, 467-470 (2006).