Abstract
The oxygen fugacities of 48 mantle xenoliths from 5 localities in southern Siberia (USSR) and Mongolia have been determined. Ferric iron contents of spinels were measured by 57Fe Mössbauer spectroscopy and oxygen fugacities calculated from spinel-olivineorthopyroxene equilibrium. The samples studied represent the major types of upper mantle lithologies including spinel and garnet peridotites and pyroxenites, fertile and depleted peridotites and anhydrous and metasomatized samples which come from diverse tectonic settings. Extensive geochemical and isotope data are also available for these samples. Oxygen fugacity values for most central Asian xenoliths fall within the range observed in peridotite xenoliths from other continental regions at or slightly below the FMQ buffer. However, xenoliths from the Baikal rift zone are the most reduced among xenoliths for which Mössbauer data on spinels are available. They yield fO2 values similar to those in oceanic peridotites and MORBs, while xenoliths in other occurrences have higher fO2s. In general, the continental lithosperic mantle is more oxidized than MORB-like oceanic mantle. This difference seems to be due to incorporation of oxidized material into some parts of the subcontinental mantle as a result of subduction of oceanic crust. Garnet- and garnet-spinel lherzolites from the Baikal rift area have slightly higher oxygen fugacities than shallower spinel lherzolites. Oxygen fugacity does not appear to be correlated with the degree of depletion of peridotites, and its values in peridotites and pyroxenites are very much alike, suggesting that partial melting (at least at moderate degrees) takes place at essentially the same fO2s that are now recorded by the residual material. Modally (amphibole- and phlogopitebearing) and cryptically metasomatized xenoliths from the Baikal rift zone give the same fO2 values as depleted anhydrous peridotites, suggesting that solid-melt-fluid reactions in the continental rift mantle also take place without substantial change in redox state. This is in contrast to other tectonic environments where metasomatism appears to be associated with oxidation.
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References
Arculus RJ, Delano JW (1981) Intrinsic oxygen fugacity measurements: techniques and results from upper mantle peridotites and megacryst assemblages. Geochim Cosmochim Acta 45:899–913
Arculus RJ, Dawson JB, Mitchell RH, Gust DA, Holmes RD (1984) Oxidation state of the upper mantle recorded by megacryst ilmenite in kimberlite and type A and B spinel lherzolites. Contrib Mineral Petrol 85:85–94
Ballhaus C, Berry RF, Green DH (1990) Oxygen fugacity controls in the Earth's upper mantle. Nature 348:437–440
Ballhaus C, Berry RF, Green DH (1991) High pressure experimental calibration of the olivine-orthopyroxene-spinel oxygen geobarometer: implications for the oxidation state of the upper mantle. Contrib Mineral Petrol 107:27–40
Bancroft GM, Osborne MD, Fleet ME (1983) Next-nearest neighbor effects in the Mössbauer spectra of Cr-spinels: an application of partial quadrupole splittings. Solid State Comm 47:623–625
Brey GP, Köhler T (1990) Geothermobarometry in four-phase lherzolites II. New thermobarometers, and practical assessment of existing thermobarometers. J Petrol 31:1353–1378
Bryndzia LT, Wood BJ (1990) Oxygen thermobarometry of abyssal spinel peridotites: the redox state and C-O-H volatile composition of the earth's sub-oceanic upper mantle. Am J Sci 290:1093–1116
Bryndzia LT, Wood BJ, Dick HJB (1989) The oxidation state of the Earth's sub-oceanic mantle from oxygen thermobarometry of abyssal spinel peridotites. Nature 341:526–527
Canil D, Virgo D, Scarfe CM (1990) Oxidation state of mantle xenoliths from British Columbia, Canada. Contrib Mineral Petrol 104:453–462
Chen YD, Pearson NJ, O'Reilly SY, Griffin WL (1991) Applications of olivine-orthopyroxene-spinel oxygen geobarometers to the redox state of the upper mantle. J Petrol, Orogenic lherzolites and mantle processes, special vol, pp 291–306
Christie DM, Carmichael ISE, Langmuir CH (1986) Oxidation states of mid-ocean ridge basalt glasses. Earth Planet Sci Lett 79:397–411
Davidson WC (1959) Variable metric method for minimization. Argonne National Laboratory document ANL-5990
Downes H, Dupuy C (1987) Textural, isotopic and REE variations in spinel peridotite xenoliths, Massif Central, France. Earth Planet Sci Lett 82:121–135
Dyar MD, McGuire AV, Ziegler RD (1989) Redox equilibria and crystal chemistry of coexisting minerals from spinel lherzolite mantle xenoliths. Am Mineral 74:969–980
Frey FA, Prinz M (1978) Ultramafic inclusions from San Carlos, Arizona: petrologic and geochemical data bearing on their petrogenesis. Earth Planet Sci Lett 38:129–176
Ionov DA (1986) Spinel peridotite xenoliths from the Shavaryn-Tsaram volcano, northern Mongolia; petrography, mayor element chemistry and mineralogy. Geologica Carpathica 37:681–692
Ionov DA, Jagoutz E (1989) Sr and Nd isotopic composition in minerals of garnet and spinel peridotite xenoliths from the Vitim Highland: first data for mantle inclusions in the USSR. Trans (Doklady) USSR Acad Sci: Earth Sci Sect 301:232–236
Ionov DA, Kramm U, Stosch H-G (1992) Evolution of the upper mantle beneath the southern Baikal rift zone: a Sr−Nd isotope study of xenoliths from the Bartoy volcanoes. Contrib Mineral Petrol 111:235–247
Ionov DA, Stosch H-G, Kovalenko VI (1989) Lithophile trace elements in minerals of a composite mantle xenolith. Trans (Doklady) USSR Acad Sci: Earth Sci Sect 296:216–220
Kempton PD (1987) Mineralogic and geochemical evidence for differing styles of metasomatism in spinel lherzolite xenoliths: enriched mantle source regions of basalts? In: Menzies MA, Hawkesworths CJ (eds) Mantle metasomatism. Academic Press, London, pp 45–89
Kovalenko VI, Ionov DA, Yarmolyuk VV, Jagoutz E, Stosch H-G, Lugmair GW (1991) Isotope data on the evolution of the mantle and its correlation with evolution of the crust in some parts of Central Asia. Geochem Internat 28:82–92
Luth RW, Virgo D, Boyd FR, Wood BJ (1990) Ferric iron in mantle-derived garnets: implications for thermobarometry and for oxidation state of the mantle. Contrib Mineral Petrol 104:56–72
Ma X (1988) Lithospheric dynamics of China. Episodes 11:84–94
Mattioli GS, Baker MB, Rutter MJ, Stolper EM (1989) Upper mantle oxygen fugacity and its relationship to metasomatism. J Geol 97:521–536
Mattioli GS, Wood BJ (1986) Upper mantle oxygen fugacity recorded by spinel lherzolites. Nature 322:626–628
Mattioli GS, Wood BJ (1988) Magnetite activities across the MgAl2O4−Fe3O4 spinel join, with application to thermobarometric estimates of upper mantle oxygen fugacity. Contrib Mineral Petrol 98:148–162
Menzies MA, Arculus RJ, Best MG, Bergman SC, Ehrenberg SN, Irving AJ, Roden MF, Schulze DJ (1987) A record of subduction processes and within-plate volcanism in lithospheric xenoliths of the southwestern USA. In: Nixon PH (ed) Mantle xenoliths. John Wiley pp 59–74
Mercier J-CC, Nicolas A (1975) Textures and fabrics of upper mantle peridotites as illustrated by xenoliths from basalts. J Petrol 16:454–487
McDonough WF (1990) Constraints on the composition of the continental lithospheric mantle. Earth Planet Sci Lett 101:1–18
Nell J, Wood BJ (1991) High temperature electrical measurements and thermodynamic properties of Fe3O4-FeCr2O4-MgCr2O4-FeAl2O4 spinels. Am Mineral 76:405–426
O'Neill HStC, Wall VJ (1987) The olivine-spinel oxygen geobarometer, the nickel precipitation curve and the oxygen fugacity of the upper mantle. J Petrol 28:1169–1192
Press S, Witt G, Seck HA, Ionov D, Kovalenko VI (1986) Spinel peridotite xenoliths from the Tariat Depression, Mongolia. I: Major element chemistry and mineralogy of a primitive mantle xenolith suite. Geochim Cosmochim Acta 50:2587–2599
Staudacher T, Allègre CJ (1991) Cosmogenic neon in ultramafic nodules from Asia and in quartzite from Antarctica. Earth Planet Sci Lett 106:87–102
Stosch H-G, Lugmair GW, Kovalenko VI (1986) Spinel peridotite xenoliths from the Tariat Depression, Mongolia: geochemistry and Nd and Sr isotopic composition and their implications for the evolution of the subcontinental lithosphere. Geochim Cosmochim Acta 50:2601–2614
Virgo D, Luth RW, Moats MA, Ulmer GC (1988) Constraints on the oxidation state of the mantle: an electrochemical and 57Fe Mössbauer study of mantle-derived ilmenites. Geochim Cosmochim Acta 52:1781–1794
Wells P (1977) Pyroxene thermometry in simple and complex systems. Contrib Mineral Petrol 62:129–139
Wood BJ (1990) An experimental test of the spinel peridotite oxygen barometer. J Geophys Res 97:15845–15851
Wood BJ (1991) Oxygen barometry of spinel peridotites. Reviews in Mineralogy 25:417–431
Wood BJ, Virgo D (1989) Upper mantle oxidation state: ferric iron contents of lherzolite spinels by 57Fe Mössbauer spectroscopy and resultant oxygen fugacities. Geochim Cosmochim Acta 53:1277–1291
Wood BJ, Banno S (1973) Garnet-orthopyroxene and orthopyroxene-clinopyroxene relationships in simple and complex systems. Contrib Mineral Petrol 42:109–124
Wood BJ, Bryndzia LT, Johnson KE (1990) Mantle oxidation state and its relationship to tectonic environment and fluid speciation. Science 248:337–345
Woodland AB, Kornprobst J, Wood BJ (1992) Oxygen thermobarometry of orogenic lherzolite massifs. J Petrol 33:203–230
Zorin YA (1981) The Baikal rift: an example of the intrusion of asthenospheric material into the lithosphere as the cause of disruption of lithospheric plates. Tectonophysics 73:91–104
Zorin YA, Bulk TV, Novoselova MR, Turutanov EH (1988) The thickness of the lithosphere beneath the Mongol-Siberian mountain country and adjacent regions. Physics of the Earth, No7:33–42 (in Russian)
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Ionov, D.A., Wood, B.J. The oxidation state of subcontinental mantle: oxygen thermobarometry of mantle xenoliths from central Asia. Contrib Mineral Petrol 111, 179–193 (1992). https://doi.org/10.1007/BF00348950
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DOI: https://doi.org/10.1007/BF00348950