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Compositional variation of coexisting olivine, orthopyroxene and Fe/Mg-ferrite as a function of T and \(f_{O_2 }\): a geothermometer and oxygen-barometer

Abstract

A thermodynamic model is developed that describes the compositional variation of coexisting olivine, orthopyroxene, and ferrite (Fe3O4-MgFe2O4) as a function of \(f_{O_2 }\) and T. The ferrite phase has a cation distribution which varies from nearly inverse to nearly random with increasing T and is described with a model in which the number of sites per formula unit on which mixing occurs varies from 1.67 to 2.0. Given this model and the equilibrium phase composition data for coexisting olivine and ferrite at 1,300° C of Jamieson and Roeder (1984), the ferrite solution is described to an excellent approximation by a symmetric regular solution model with W ft =+14.0 ±0.3 kJ/mole. Orthopyroxene and olivine non-ideality are also considered. The T-dependence of the equilibrium constant for the oxidation reaction 6Fs+2Mt=6Fa+O2 and the two Fe/Mg exchange reactions between olivine-ferrite and olivine-orthopyroxene, are used to calculate the compositional variation of coexisting phases as a function of \(f_{O_2 }\) and T. The results are summarized on an isobaric (1 bar) \(f_{O_2 }\) −1/Tplot with the compositional variation of olivine, ferrite, and orthopyroxene shown by sets of isopleths. The ferrite isopleths intersect those of olivine and orthopyroxene at sufficiently high angles for this assemblage to serve as a sensitive geothermometer and oxygen-barometer. The model is applied to orthopyroxene-ferrite symplectite in coronas around olivine in a metamorphosed gabbro, to olivine-hosted orthopyroxene-ferrite symplectite in unmetamorphosed gabbros and norites and to olivine-hosted orthopyroxene-ferrite symplectites developed within the rims of lherzolite xenoliths.

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References

  • Ambler EP, Ashley PM (1977) Vermicular orthopyroxene-magnetite symplectites from the Wateranga layered mafic intrusion, Queensland, Australia. Lithos 10:163–172

    Google Scholar 

  • Anderson DJ, Lindsley DH (1981) A valid Margules formulation for an asymmetric ternary solution: revision of the olivine-ilmenite thermometer, with applications. Geochim Cosmochim Acta 45:847–853

    Google Scholar 

  • Barth TFW, Posnjak E (1932) Spinel structures, with and without variate atom equipoints. Z Kristallogr 82:325–341

    Google Scholar 

  • Bohlen SR, Boettcher AL (1981) Experimental investigations and geological applications of orthopyroxene geobarometry. Am Mineral 66:951–964

    Google Scholar 

  • Bonnickson KR (1954) High temperature heat contents of calcium and magnesium ferrites. Am Chem Soc J 76:1480–1482

    Google Scholar 

  • Chatillon-Colinet C, Newton RC, Perkins D, Kleppa OJ (1983) Thermochemistry of (Fe2+, Mg)SiO3 orthopyroxene. Geochim Cosmochim Acta 47:1597–1603

    Google Scholar 

  • Conte SD, C de Boor (1980) Elementary Numerical Analysis. McGraw-Hill, New York

    Google Scholar 

  • Davidson PM, Mukhopadhyay DK (1984) Ca-Fe-Mg olivines: phase relations and a solution model. Contrib Mineral Petrol 86:256–263

    Google Scholar 

  • Engi M (1983) Equilibria involving Al-Cr spinel: Mg-Fe exchange with olivine. Experiments, thermodynamic analysis, and consequences for geothermometry. Am J Sci 283-A:29–71

    Google Scholar 

  • Evans BW, Frost BR (1975) Chrome-spinel in progressive metamorphism — a preliminary analysis. Geochim Cosmochim Acta 39:959–972

    Google Scholar 

  • Faller JG, Birchenall CE (1970) The temperature dependence of ordering in magnesium ferrite. J Appl Crystallogr 3:496–503

    Google Scholar 

  • Gordeev IV, Tretjakov JD (1963) Thermodynamics of solid solutions of magnesium ferrite with magnetite. Russ J Inorg Chem 8:943–947

    Google Scholar 

  • Haggerty SE, Baker I (1967) The alteration of olivine in basaltic and associated lavas. Part I: High temperature alteration. Contrib Mineral Petrol 16:233–257

    Google Scholar 

  • Hahn WC, Muan A (1962) Activity measurements in oxide soid solutions. The system “FeO”-MgO in the temperature interval 1,100° to 1,300° C. Trans Met Soc AIME 224:416–420

    Google Scholar 

  • Hewitt DA (1978) A redetermination of the fayalite-magnetite-quartz equilibrium between 650° and 850° C. Am J Sci 278:715–724

    Google Scholar 

  • Irvine TN (1965) Chromian spinel as a petrogenetic indicator. Part 1: Theory. Can J Earth Sci 2:648–672

    Google Scholar 

  • Irvine TN (1967) Chromian spinel as a petrogenetic indicator. Part 2: Petrologic applications. Can J Earth Sci 4:71–103

    Google Scholar 

  • Jamieson HE, Roeder PL (1984) The distribution of Mg and Fe2+ between olivine and spinel at 1,300° C. Am Mineral 69:283–291

    Google Scholar 

  • Jaoul O, Froidevaux C, Durham WB, Michault M (1980) Oxygen self-diffusion in forsterite: implications for the high temperature creep mechanism. Earth Planet Sci Lett 47:391–397

    Google Scholar 

  • Johnston AD, Stout JH (1984a) Development of orthopyroxene—Fe/Mg ferrite symplectites by continuous olivine oxidation. Contrib Mineral Petrol 88:196–202

    Google Scholar 

  • Johnston AD, Stout JH (1984b) A highly oxidized ferrian salite-, kennedyite-, forsterite-, and rhönite-bearing alkali gabbro from Kauai, Hawaii and its mantle xenoliths. Am Mineral 69:57–68

    Google Scholar 

  • Johnston AD, Stout JH, Murthy VRM (1985) Geochemistry and origin of some unusually oxidized alkaline rocks from Kauai, Hawaii. J Volcanol Geotherm Res 25:225–248

    Google Scholar 

  • Kilinc A, Carmichael ISE, Rivers ML, Sack RO (1983) The ferric-ferrous ratio of natural silicate liquids equilibrated in air. Contrib Mineral Petrol 83:136–140

    Google Scholar 

  • King EG, Barany R, Weiler WW, Pankratz LB (1967) Thermodynamic properties of forsterite and serpentine. US Bur Mines Rept Inv 6962, 19 p

  • Kohlstedt DL, Vander Sande JB (1975) An electron microscopy study of naturally occurring oxidation produced precipitates in iron-bearing olivines. Contrib Mineral Petrol 55:13–24

    Google Scholar 

  • Mason TO, Bowen HK (1981) Electronic conduction and thermopower of magnetite and iron-aluminate spinels. J Am Cer Soc 64:237–242

    Google Scholar 

  • Matsui Y, Nishizawa O (1974) Iron(II)-magnesium exchange equilibrium between olivine and calcium-free pyroxene over a temperature range 800° C to 1,300° C. Bull Soc Fr Mineral Cristallogr 97:122–130

    Google Scholar 

  • McSween HY, Mystrom PG (1979) Mineralogy and petrology of the Dutchman's Creek gabbroic intrusion, South Carolina. Am Mineral 64:531–545

    Google Scholar 

  • Medaris LG (1969) Partitioning of Fe++ and Mg++ between coexisting synthetic olivine and orthopyroxene. Am J Sci 267:945–968

    Google Scholar 

  • Mozzi RL, Palladino AE (1963) Cation distributions in non-stoichiometric magnesium ferrite. J Chiem Phys 39:435–439

    Google Scholar 

  • Muir ID, Tilley CE (1957) Contributions to the petrology of Hawaiian basalts. 1. The picrite-basalts of Kilauea. Am J Sci 255:241–253

    Google Scholar 

  • Myers J, Eugster HP (1983) The system Fe-Si-O: Oxygen buffer calibrations to 1,500 K. Contrib Mineral Petrol 82:75–90

    Google Scholar 

  • Nafziger RH, Muan A (1967) Equilibrium phase compositions and thermodynamic properties of olivines and pyroxenes in the system MgO-“FeO”-SiO2. Am Mineral 52:1364–1385

    Google Scholar 

  • Navrotsky A, Kleppa OJ (1967) The thermodynamics of cation distributions in simple spinels. J Inorg Nucl Chem 29:2701–2714

    Google Scholar 

  • O'Neill HStC, Navrotsky A (1984) Cation distributions and thermodynamic properties of binary spinel solid solutions. Am Mineral 69:733–753

    Google Scholar 

  • O'Neill HStC, Wood BJ (1979) An experimental study of Fe-Mg partitioning between garnet and olivine and its calibration as a geothermometer. Contrib Mineral Petrol 70:59–70

    Google Scholar 

  • Peterson RC, Jamieson HE (1985) Cation distribution in Mg-Fe spinels. Geol Soc Amer Abstr with Progr 17:687

    Google Scholar 

  • Ramberg H, DeVore G (1951) The distribution of Fe++ and Mg++ in coexisting olivines and pyroxenes. J Geol 59:193–210

    Google Scholar 

  • Reznitskii LA, Khomyakov KG, Korzhukov NG, Orel SE (1969) Calorimeter for measuring true specific heats of ferrites between 300 and 1,000° C. Russ J Phys Chem 43:1216–1219

    Google Scholar 

  • Robie RA, Hemingway BS, Fisher JR (1979) Thermodynamic properties of minerals and related substances at 298.15 K and 1 bar (105 pascals) pressure and at higher temperatures. US Geological Survey Bulletin, 1452, 456 pp

  • Robie RA, Finch CB, Hemingway BS (1982a) Heat capacity and entropy of fayalite (Fe2SiO4) between 5.1 and 383 K: comparison of calorimetric and equilibrium values for the QFM buffer reaction. Am Mineral 67:463–469

    Google Scholar 

  • Robie RA, Hemingway BS, Takei H (1982b) Heat capacities and entropies of Mg2SiO4, Mn2SiO4 and Co2SiO4 between 5 and 380 K. Am Mineral 67:470–482

    Google Scholar 

  • Robinson GR, Haas JL, Schafer CM, Haselton HT (1983) Thermodynamic and thermophysical properties of selected phases in the MgO-SiO2-H2O-CO2, CaO-Al2O3-SiO2-H2O-CO2, and Fe-FeO-Fe2O3-SiO2 chemical systems, with special emphasis on the properties of basalts and their mineral components. US Geol Surv, Open File Rep, 83–79, 429 pp

  • Roeder PL, Campbell IH, Jamieson HE (1979) A re-evaluation of the olivine-spinel geothermometer. Contrib Mineral Petrol 68:325–334

    Google Scholar 

  • Sack RO (1980) Some constraints on the thermodynamic mixing properties of Fe-Mg orthopyroxenes and olivines. Contrib Mineral Petrol 71:257–269

    Google Scholar 

  • Sack RO (1982) Spinels as petrogenetic indicators: Activity-composition relations at low pressures. Contrib Mineral Petrol 79:169–186

    Google Scholar 

  • Saxena SK (1973) Thermodynamics of Rock-Forming Crystalline Solutions. Springer, Berlin Heidelberg New York

    Google Scholar 

  • Schwerdtfeger K, Muan A (1966) Activities in olivine and pyroxene solid solutions of the system Fe-Mn-Si-O at 1,150° C. Trans Metall Soc AIME 236:201–211

    Google Scholar 

  • Speidel DH, Osborn EF (1967) Element distribution among coexisting phases in the system MgO-FeO-Fe2O3-SiO2 as a function of temperature and oxygen fugacity. Am Mineral 52:1139–1152

    Google Scholar 

  • Stern CR, Huang W-L, Wyllie PJ (1975) Basalt-andesite-rhyolite H2O: crystallization intervals with excess H2O and H2O-under-saturated liquidus surfaces to 35 kilobars, with implications for magma genesis. Earth Planet Sci Lett 28:189–196

    Google Scholar 

  • Stull DR, Prophet H (1971) JANAF thermochemical tables. Nat Stan Ref Data Serv Nat Bur Stand 37

  • Tellier J-C (1967) Sur la substitution dan le ferrite de magnésium des ions ferriques par les ions trivalents, tétravalents et pentavalents. Rev Chim Mineral 4:325–365

    Google Scholar 

  • Thompson JB Jr (1967) Thermodynamik properties of simple solutions. In: PH Abelson (ed) Researches in Geochemistry, Vol 2, Wiley New York, pp 340–361

    Google Scholar 

  • Trestman-Matts A, Dorris SE, Mason TO (1984) Thermoelectric determination of cation distributions in Fe3O4-MgFe2O4. J Am Cer Soc 67:69–74

    Google Scholar 

  • Tretjakov JD, Schmalzried H (1965) Zur Thermodynamik von Spinellphase. Ber Bunsengesellsch 69:396–402

    Google Scholar 

  • van Lamoen H (1979) Coronas in olivine gabbros and iron ores from Susimäki and Riuttamaa Finland. Contrib Mineral Petrol 68:259–268

    Google Scholar 

  • Williams RJ (1971) Reaction constants in the system Fe-MgO-SiO2-O2 at 1 atm. between 900° and 1,300° C: experimental results. Am J Sci 270:334–360

    Google Scholar 

  • Williams RJ (1972) Activity-composition relations in the fayalite-forsterite solid solution between 900° and 1,300° C at low pressures. Earth Planet Sci Lett 15:296–300

    Google Scholar 

  • Wood BJ, Fraser DJ (1977) Elementary Thermodynamics for Geologists. Oxford UK, Oxford Univ Press, 303 p

    Google Scholar 

  • Wood BJ, Nicholls J (1978) The thermodynamic properties of reciprocal solid solutions. Contrib Mineral Petrol 66:389–400

    Google Scholar 

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Johnston, A.D., Beckett, J.R. Compositional variation of coexisting olivine, orthopyroxene and Fe/Mg-ferrite as a function of T and \(f_{O_2 }\): a geothermometer and oxygen-barometer. Contr. Mineral. and Petrol. 94, 323–332 (1986). https://doi.org/10.1007/BF00371441

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  • DOI: https://doi.org/10.1007/BF00371441

Keywords

  • Ferrite
  • Olivine
  • Equilibrium Phase
  • Solution Model
  • Thermodynamic Model