Abstract
An equation for the excess free energy of melts containing all major components is derived from published experimental data on equilibria between silicate liquids with either metallic iron or spinel at controlled oxygen partial pressure. The FeO activities in mafic and ultramafic magmas calculated with this equation were used to develop an oxygen barometer (geoxometer) for the association spinel + melt. Data derived with the application of the geoxometer confirm that meymechite magmas in the Siberian trap province had oxygen fugacities higher than in other magmatic systems. The origin of lower lithospheric domains with elevated redox potential can be explained by the intense diffusion of hydrogen from zones in which water-rich near-solidus melts from asthenospheric sources were emplaced into harzburgites, which had lost water and other incompatible elements in the course of earlier large-scale melting.
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H. S. C. O’Neill and S. M. Eggins, “The effect of melt composition on trace element partitioning: an experimental investigation of the activity coefficients of FeO, NiO, CoO, MoO2 and MoO3 in silicate melts,” Chem. Geol. 186, 151–181 (2002).
A. A. Borisov, “Experimental study of the influence of SiO2 on the solubility of cobalt and iron in silicate melts,” Petrology 15(6), 523–529 (2007).
A. V. Girnis, “Olivine-orthopyroxene-melt equilibrium as a thermobarometer for mantle-derived magmas,” Petrology 11, 101–114 (2003).
B. J. Wood, L. T. Bryndzya, and K. E. Johnson, “Mantle oxidation state and its relationship to tectonic environment and fluid speciation,” Science 248, 337–345 (1990).
T. J. B. Holland and R. Powell, “An internally consistent thermodynamic data set for phases of petrological interest,” J. Metamorph. Geol. 16, 309–343 (1998).
K. J. Jayasuriya, H. S. C. O’ Neill, A. J. Berry, and S. J. Campbell, “A Mossbauer study of the oxidation state of Fe in silicate melts,” Am. Mineral. 89, 1597–1609 (2004).
P. C. Hess, Thermodynamic mixing properties and the structure of silicate melts, in Reviews in Mineralogy ed. by J. F. Stebbins, P. F. McMillan, and D. B. Dingwell (Mineral. Soc. Am., Washington, 1995), Vol. 32, pp. 145–189.
H. S. C. O’Neill and A. J. Berry, “Activity coefficients at low dilution of CrO, NiO and CoO in melts in the system CaO-MgO-Al2O3-SiO2 at 1400°C: using the thermodynamic behaviour of transition metal oxides in silicate melts to probe their structure,” Chem. Geol. 237, 77–89 (2006).
M. J. Toplis, “The thermodynamics of iron and magnesium partitioning between olivine and liquid: criteria for assessing and predicting equilibrium in natural and experimental systems,” Contrib. Mineral. Petrol. 149, 22–39 (2005).
M. S. Ghiorso and R. S. Sack, “Chemical mass transfer in magmatic processes. IV. A revised and internally consistent thermodynamic model for the interpolation and extrapolation of liquid-solid equilibria in magmatic systems at elevated temperatures and pressures,” Contrib. Mineral. Petrol. 119, 197–202 (1995).
A. A. Ariskin and G. N. Barmina, Modeling of Phase Equilibria during Crystallization of Basaltic Magmas (Nauka, Moscow, 2000) [in Russian].
I. D. Ryabchikov, I. P. Solovova, T. Ntaflos, and A. Büchl, “Subalkaline picrobasalts and plateau basalts from the Putorana Plateau (Siberian continental flood basalt province): I. Mineral compositions and geochemistry of major and trace elements,” Geochem. Int. 39(5), 415–431 (2001).
C. E. Ford, D. G. Russell, J. A. Craven, and M. R. Fisk, “Olivine-liquid equilibria: temperature, pressure and composition dependence of the crystal/liquid cation partition coefficients for Mg, Fe2+, Ca and Mn,” J. Petrol. 24, 256–265 (1983).
V. S. Kamenetsky, A. J. Crawford, and S. Meffre, “Factors controlling chemistry of magmatic spinels: an empirical study of associated olivine, Cr-spinel and melt inclusions from primitive rocks,” J. Petrol. 42, 655–671 (2001).
A. V. Sobolev, V. S. Kamenetskii, and N. N. Kononkova, “New data on petrology of the Siberian meimechites,” Geokhimiya, 1084–1095 (1991).
I. D. Ryabchikov and L. N. Kogarko, “A new version of the spinel-olivine-pyroxene oxybarometer and extreme redox differentiation in magmatic systems of mantle sources,” Dokl. Earth Sci. 430, 248–251 (2010).
A. B. Sobolev, C. B. Sobolev, D. V. Kuzmin, K. N. Malitch, and A. G. Petrunin, “Siberian meimechites: origin and relation to flood basalts and kimberlites,” Russ. Geol. Geophys. 50(12), 999–1033 (2009).
J. E. Mungall, J. J. Hanley, N. T. Arndt, and A. Debecdelievre, “Evidence from meimechites and other low-degree mantle melts for redox controls on mantle-crust fractionation of platinum-group elements,” Proc. Nat. Acad. Sci. U.S.A. 103, 12695–12700 (2006).
I. D. Ryabchikov, “Oxygen potential of high-magnesium magmas,” Dokl. Earth Sci. 448, 149–152 (2012).
L. N. Kogarko and I. D. Ryabchikov, “Conditions of generation of meimechite magmas (Polar Siberia): geochemical data,” Geokhimiya, 1699–1709 (1995).
I. D. Ryabchikov, I. P. Solovova, L. N. Kogarko, G. P. Brai, T. Ntaflos, S. G. Simakin, “Thermodynamic parameters of generation of meymechites and alkaline picrites in the Maymecha-Kotui Province: evidence from melt inclusions,” Geochem. Int. 40(11), 1031–1041 (2002).
L. N. Kogarko and I. D. Ryabchikov, “Geochemical evidence for meimechite magma generation in the subcontinental lithosphere of Polar Siberia,” J. Asian Earth Sci. 18, 195–203 (2000).
J. F. Allan, T. Falloon, R. F. Pedersen, B. Sh. Lakka-pragada, J. H. Natland, and J. Malpas, “Petrology of selected Leg 147 basaltic lavas and dikes,” Proc. ODP, Sci. Results, Ocean Drilling Program, College Station, TX, Ed. by C. Mevel, K. M. Gillis, J. F. Allan, and P. S. Meyer, 147, 173–185, (1996).
J. H. Natland, “Partial melting of a lithologically heterogeneous mantle: inferences from crystallization histories of magnesian abyssal tholeiites from the Siqueiros fracture zone,” in Magmatism in the Ocean Basins, Ed. by A.D. Saunders and M.J. Norry, Geol. Soc. Spec. Publ. 42, 41–70 (1989).
A. W. McNeill, The Crystallisation History of Normal Mid-Ocean Ridge Basalts from the Eastern Pacific Ocean and Implications for the Composition of Primary Mid-Ocean Ridge Magmas Evidence from Mineralogy, Pillow-Rim Glasses and Melt Inclusion Studies (University of Tasmania, 1997).
L. V. Danyushevskii, A. V. Sobolev, and L. V. Dmitriev, “Low-Ti orthopyroxene-bearing tholeiite as a new type of oceanic rift tholeiites,” Doklady Akad. Nauk SSSR 292, 102–105 (1987).
T. J. Falloon, L. V. Danyushevsky, A. Ariskin, D. H. Green, C. E. Ford, “The application of olivine geothermometry to infer crystallization temperatures of parental liquids: implications for the temperature of MORB magmas,” Chem. Geol. 41, 207–233 (2002).
I. D. Ryabchikov, “Redox equilibria in upper mantle,” Dokl. Akad. Nauk SSSR 268, 703–706 (1983).
H. S. C. O’Neill, D. C. Rubie, D. Canil, C. A. Geiger, C. R. Ross, F. Seifert, and A. B. Woodland, “Ferric iron in the upper mantle and in transition zone assemblages: implications for relative oxygen fugacities in the mantle,” in Evolution of the Earth and Planets, Ed. by E. Takahashi, R. Jeanloz, and D.C. Rubie, Geophys. Monogr. Am. Geophys. Union, 74, 73–88 (1993).
D. J. Frost, C. Liebske, F. Langenhorst, C. A. McCammon, R. G. Tronnes, and D. C. Rubie, “Experimental evidence for the existence of iron-rich metal in the Earth’s lower mantle,” Nature 428, 409–412 (2004).
D. J. Frost and C. A. McCammon, “The redox state of Earth’s mantle,” Annu. Rev. Earth Planet. Sci. 36, 389–420 (2008).
A. Rohrbach, C. Ballhaus, U. Golla-Schindler, P. Ulmer, V. S. Kamenetsky, and D. V. Kuzmin, “Metal saturation in the upper mantle,” Nature 449, 456–458 (2007).
I. D. Ryabchikov, L. N. Kogarko, and I. P. Solovova, “Physicochemical conditions of magma formation at the base of the Siberian plume: insight from the investigation of melt inclusions in the meymechites and alkali picrites of the Maimecha-Kotui province,” Petrology 17(3), 287–299 (2009).
E. K. Hauri, G. A. Gaetani, and T. H. Green, “Partitioning of water during melting of the Earth’s upper mantle at H2O-undersaturated conditions,” Earth Planet. Sci. Lett. 248, 715–734 (2006).
S. Demouchy and S. Mackwell, “Mechanisms of hydrogen incorporation and diffusion in iron-bearing olivine,” Phys. Chem. Minerals 33, 347–355 (2006).
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Original Russian Text © I.D. Ryabchikov, L.N. Kogarko, 2013, published in Geokhimiya, 2013, Vol. 51, No. 12, pp. 1055–1065.
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Ryabchikov, I.D., Kogarko, L.N. FeO activity and oxygen potential in magnesian magmas. Geochem. Int. 51, 949–958 (2013). https://doi.org/10.1134/S0016702913120070
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DOI: https://doi.org/10.1134/S0016702913120070