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New Mössbauer measurements of Fe3+/ΣFe in chromites from the mantle section of the Oman ophiolite: evidence for the oxidation of the sub-oceanic mantle

Published online by Cambridge University Press:  05 July 2018

H. Rollinson*
Affiliation:
School of Science, University of Derby, Kedleston Road, Derby DE22 1GB, UK
J. Adetunji
Affiliation:
School of Science, University of Derby, Kedleston Road, Derby DE22 1GB, UK
A. A. Yousif
Affiliation:
Department of Physics, Sultan Qaboos University, PO Box 36, Al-Khod 123, Sultanate of Oman
A. M. Gismelseed
Affiliation:
Department of Physics, Sultan Qaboos University, PO Box 36, Al-Khod 123, Sultanate of Oman

Abstract

Room temperature Mössbauer and electron-probe measurements of Fe3+/ΣFe in chromite from the mantle section of the Oman ophiolite define two groups of samples: a low Fe3+/ΣFe group (with Fe3+/ΣFe = 0.21–0.36) have cr# = Cr/(Cr + Al) in the range 0.49–0.75, whereas a smaller more geographically localized high Fe3+/ΣFe group (with Fe3+/ΣFe = 0.71–0.78) have a more restricted range of cr# ratios of 0.72–0.75. The low Fe3+/ΣFe chromitites have very variable Fe3+/ΣFe ratios. They are thought to have crystallized from melts that have interacted with depleted mantle and thereby acquired their variable Fe3+/ΣFe ratio. The high Fe3+/ΣFe chromitites are restricted to one small area of the mantle and their high oxidation state is thought to be post magmatic. They are either the product of later heating, related to melt flux or interaction with a later oxidising melt. A difference in oxygen fugacity between the MORB-depleted harzburgite host, which is at the quartz–fayalite–magnetite (QFM) buffer and the later chromite-bearing melts (QFM + 2) implies that there is a real difference in the oxidation state of the MORB and arc-magma sources.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2016

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References

Al-Alawi, Z., Gismelseed, A.M., Yousif, A.A., Worthing, M.A., Sutherland, H.H., Rais, A.M., Elzain, M.E. and Al-Rawas, A.D. (1996) Cation distribution in natural chromites from Oman. Sultan Qaboos University Journal of Science and Technology, 1, 5561.Google Scholar
Ballhaus, C., Berry, R.F. and Green, D.H. (1991) High pressure experimental calibration of the olivineorthopyroxene- spinel oxygen geobarometer: implications for the oxidation state of the upper mantle. Contributions to Mineralogy and Petrology, 107, 2740.CrossRefGoogle Scholar
Bosi, F., Andreozzi, G.B., Ferrini, V. and Lucchesi, S. (2004) Behaviour of cation vacancy in kenotetrahedral Cr-spinels from Albanian eastern belt ophiolites. America. Mineralogist, 89, 13671373 CrossRefGoogle Scholar
Canil, D. (2002) Vanadium in peridotites, mantle redox and tectonic environments: Archaean to present. Earth and Planetary Science Letters, 195, 7590.CrossRefGoogle Scholar
Carmichael, I.S.E. (1991) The redox states of basic and silicic magmas: a reflection of their source regions? Contributions to Mineralogy an. Petrology, 106, 129141 Google Scholar
Cottrell, E. and Kelley, K.A. (2011) The oxidation state of Fe in MORB glasses and the oxygen fugacity of the upper mantle. Earth and Planetary Scienc. Letters, 305, 270282 Google Scholar
Dare, S.A.S., Pearce, J.A., McDonald, I. and Styles, M.T. (2009) Tectonic discrimination of peridotites using fO2-Cr# and Ga-Ti-FeIII systematics in chrome spinel. Chemical Geology. 261, 199216 CrossRefGoogle Scholar
Godard, M., Jousselin, D. and Bodinier, J.L. (2000) Relationships between geochemistry and structure beneath a palaeo-spreading centre: a study of the mantle section of the Oman ophiolite: an ICP-MS study. Earth and Planetary Scienc. Letters, 180, 133148 Google Scholar
Kamenetsky, V.S., Crawford, A.J. and Meffre, S. (2001) Factors controlling chemistry of magmatic spinel: an empirical study of associated olivine, Cr-spinel and melt inclusions from primitive rocks. Journal of Petrology, 42, 655671 CrossRefGoogle Scholar
Leblanc, M. and Ceulneer, G. (1992) Chromite crystallization in a multicellular magma flow: evidence from a chromitite dike in the Oman Ophiolite. Lithos, 27, 231257 CrossRefGoogle Scholar
Lee, C-T.A., Luffi, P., Le Roux, V., Dasgupta, R., Albarede, F. and Leeman, W.F. (2010) The redox state of arc mantle using Zn/Fe systematic. Nature, 468, 681685 CrossRefGoogle Scholar
Lenaz, D., Andreozzi, G.B., Mitra, S., Bidyananda, M. and Princivalle, F.(2004) Crystal chemical and 57Fe Mossbauer study of chromite from the Nuggihalli schist belt, (India). Mineralogy and Petrology, 80, 4557.CrossRefGoogle Scholar
Li, Z., Ping, J.Y., Jin, M.Z. and Liu, M.L. (2002) Distribution of Fe2+ and Fe3+ and next-nearest neighbour effects in natural chromites: comparison between results of QSD and Lorentzian doublet analysis. Physics and Chemisty of Minerals, 29, 485494 CrossRefGoogle Scholar
Martignago, F., Dal Negro, A. and Carbonin, S. (2003) How Cr3+ and Fe3+ affect Mg-Al order-disorder transformation at high temperature in natural spinels. Physics an. Chemistry of Minerals, 30, 401408 CrossRefGoogle Scholar
Menegazzo, G., Carbonin, S. and Della Giusta, A. (1997) Cation and vacancy distribution in an artificially oxidized natural spinel. Mineralogica. Magazine, 61, 411421 Google Scholar
Mitra, S., Pal, T. and Pal, T. (1991) Petrogenetic implication of Mössbauer hyperfine parameters of Fe3+-chromites from Sukinda (India) ultramafites. Mineralogica. Magazine, 55, 535542 Google Scholar
Nell, J. and Pollak, H. (1998) Cation to anion stoichiometry of chromite: a new perspective. Hyperfin. Interactions, 111, 309312 Google Scholar
Óneill, H. St C. and Navrotsky, A. (1983) Simple spinels: crystallographic parameters, cation radii, lattice energies and cation distribution. America. Mineralogist, 68, 181194 Google Scholar
Pal, T., Moon, H. and Mitra, S. (1994) Distribution of iron cation in natural chromites at different stages of oxidation - a 57Fe Mössbauer investigation. Journal of the Geological Society of India, 44, 5364.Google Scholar
Pearce, J., Barker, P.F., Edwards, S.J., Parkinson, I.J. and Leat, P.T. (2000) Geochemistry and tectonic significance of peridotites from the South Sandwich arc-basin system, South Atlantic. Contributions to Mineralogy and Petrology, 139, 3653.CrossRefGoogle Scholar
Quintiliani, M. (2005) 57Fe Mössbauer spectroscopy analysis of spinels: Fe3+/Fetot quantification accuracy and consequences on fO2 estimate. Periodico d. Mineralogia, 74, 139146 Google Scholar
Quintiliani, M., Andreozzi, G.B. and Graziani, G. (2006) Fe2+ and Fe3+ quantification by different approaches and fO2 estimation for Albanian Cr-spinels. America. Mineralogist, 91, 907916 CrossRefGoogle Scholar
Rais, A., Yousif, A.A., Al-Shihi, M.H., Al-Rawas, A.D., Gismelseed, A.M. and El-Zain, M.E. (2003) Cation distribution and magnetic properties of natural chromites. Physica Status Solid. (b), 239, 439446 Google Scholar
Roeder, P.L. and Reynolds, I. (1991) Crystallization of chromite and chromium solubility in basaltic melts. Journal of Petrology, 32, 909934 CrossRefGoogle Scholar
Rollinson, H.R. (2005) Chromite in the mantle section of the Oman ophiolite: a new genetic model. Islan. Arc, 14, 542550 Google Scholar
Rollinson, H.R. (2008) The geochemistry of mantle chromitites from the northern part of the Oman ophiolite: inferred parental melt compositions. Contributions to Mineralogy an. Petrology, 156, 273288 Google Scholar
Schmidbauer, E. (1987) Fe-57 Mössbauer-spectroscopy and magnetization of cation deficient Fe2TiO4 and FeCr2O4 2. Magnetization data. Physics an. Chemistry of Minerals, 15, 201207 CrossRefGoogle Scholar
Trumbull, R.B., Yang, J-S., Robinson, P.T., Di Perro, S., Vennemann, T. and Weidenbeck, M. (2009) The carbon isotope composition of natural SiC (moissanite) from the Earth’s mantle: new discoveries from ophiolites. Lithos, 113, 612620 CrossRefGoogle Scholar
Wood, B.J. and Virgo, D. (1989) Upper mantle oxidation state: ferric iron contents of Iherzolite spinels by 57Fe Mö ssbauer spectroscopy and resultant oxygen fugacities. Geochimica et Cosmochimica Acta, 53, 12771291 CrossRefGoogle Scholar