Skip to main content
Log in

Garnet-orthopyroxene and orthopyroxene-clinopyroxene relationships in simple and complex systems

  • Published:
Contributions to Mineralogy and Petrology Aims and scope Submit manuscript

Abstract

Use of simple mixing models of orthopyroxene and garnet solid solutions enables extrapolation of experimentally determined equilibria in the MgSiO3-Al2O3 system to uninvestigated parts of pressure-temperature-composition space. Apparent discrepancies in the experimental data for simple and multicomponent systems may be explained by considering the effect of CaO and FeO on reducing pyrope activity in the garnet solid solutions. Equilibration pressures of natural garnet-orthopyroxene assemblages may be calculated, provided temperatures are known, from a combination of the experimental data on the MgSiO3-Al2O3 system and analyses of coexisting natural phases.

Despite the presence of a compositional gap in the system, the solubility of enstatite in diopside coexisting with orthopyroxene can also be approximately treated by an ideal solution model. An empirical approach has been developed to take account of Fe2+ on the orthopyroxene-clinopyroxene miscibility gap in natural systems in order to calculate equilibration temperatures of 2-pyroxene assemblages. The model presented reproduces almost all of the available experimental data for multicomponent systems to within 60° C.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  • Atkins, F. B.: Pyroxenes of the Bushveld Intrusion, South Africa, J. Petrol. 10, 222–49 (1969)

    Google Scholar 

  • Beeson, M. H., Jackson, E. D.: Origin of Garnet-Pyroxenite Xenoliths at Salt Lake Grater, Oahu, Mineral. Soc. Amer. Spec. Pap. 3, 95–112 (1970)

    Google Scholar 

  • Bowen, N. L., Schairer, J. F.: The system MgO-FeO-SiO2. Am. J. Sci. 29, 151–217 (1935)

    Google Scholar 

  • Boyd, F. R.: Electron-probe study of Diopside inclusions from Kimberlite, Amer. J. Sci. 267A, 50–69 (1969)

    Google Scholar 

  • Boyd, F. R.: Garnet peridotites and the system CaSiO3-MgSiO3-Al2O3. Mineral. Soc. Amer. Spec. Pap. 3, 63–75 (1970)

    Google Scholar 

  • Boyd, F. R., England, J. L.: The system enstatite-pyrope. Yearbook Carnegie Inst. Wash. 63, 157–161 (1964)

    Google Scholar 

  • Boyd, F. R., Nixon, P. H.: Ultramafic nodules from the Thaba Putsoa Kimberlite Pipe. Yearbook Carnegie Inst. Wash. 71, 382–373 (1972)

    Google Scholar 

  • Brown, G. M.: Pyroxenes from the Early and Middle Stages of Fractionation of the Skaergaard Intrusion, East Greenland, Mineral. Mag. 31, 511–43 (1957)

    Google Scholar 

  • Brown, G. M.: Experimental studies on inversion relations in natural pigeonitic pyroxenes. Yearbook Carnegie Inst. Wash. 66, 347–353 (1967)

    Google Scholar 

  • Carmichael, I. S. E.: The iron-titanium oxides of salic volcanic rocks and their associated ferromagnesium silicates. Contr. Mineral. and Petrol. 14, 36–64 (1967a)

    Google Scholar 

  • Carmichael, I. S. E.: The mineralogy of Thingmuli, a Tertiary volcano in eastern Iceland. Am. Mineralogist 52, 1815–1841 (1967b)

    Google Scholar 

  • Chatterjee, N. D., Schreyer, W.: The reaction enstatitess+sillimanite⇌sapphiriness+quartz Contr. Mineral. and Petrol. 36, 49–62 (1972)

    Google Scholar 

  • Davis, B. T. C., Boyd, F. R.: The join Mg2Si2O6-CaMgSi2O6 at 30 kilobars pressure and its application to pyroxenes from Kimberlites, J. Geophys. Res. 71, 3567–3576 (1966)

    Google Scholar 

  • Evans, B. W., Moore, J. G.: Mineralogy as a function of depth in the prehistoric Makaopuhi tholeiitic lava lake, Hawaii. Contr. Mineral. and Petrol. 17, 85–115 (1968)

    Google Scholar 

  • Green, D. H.: Conditions of melting of basanite magma from Garnet Peridotite. Earth Planet. Sci. Lett. 17, 456–465 (1973)

    Google Scholar 

  • Green D. H., Hibberson, W.: Experimental duplication of conditions of precipitation of high pressure phenocrysts in a basaltic magma. Phys. Earth Planet. Int. 3, 247–254 (1970)

    Google Scholar 

  • Green, D. H., Ringwood, A. E.: The genesis of basaltic magmas. Contr. Mineral. and Petrol. 15, 103–190 (1967)

    Google Scholar 

  • Green, D. H., Ringwood, A. E.: Mineralogy of peridotitic compositions under upper mantle conditions. Phys. Earth Planet. Interiors 3, 359–371 (1970)

    Google Scholar 

  • Hafner, S. S., Virgo, D., Warburton, D.: Cation distributions and cooling history of clinopyroxenes from Oceanus Procellarum. Proceedings 2nd Lunar Science Conference, Vol. 1, 99–108 (1971)

    Google Scholar 

  • Heming, R. F., Carmichael, I. S. E.: High-temperature pumice flows from Rabaul Caldera, Papua, New Guinea, Contr. Mineral. and Petrol. 38, 1–20 (1973)

    Google Scholar 

  • Himmelberg, G. R., Loney, R. A.: Petrology of the Vulcan Peak Alpine-Type Peridotite, Southwestern Oregon, Geol. Soc. Am. Bull. 84, 1585–1600 (1973)

    Google Scholar 

  • Howie, R. A.: The geochemistry of the Charnockite series of madras, India. Trans. Roy. Soc. Edinburgh 62, 725–768 (1955)

    Google Scholar 

  • Kushiro, I., Shimizu, N., Nakamura, Y.: Compositions of coexisting liquid and solid phases formed upon melting of natural Garnet and Spinel lherzolites at high pressures: A preliminary report. Earth Planet. Sci. Lett. 14, 19–25 (1972)

    Google Scholar 

  • Lindsley, D. H., Munoz, J. L.: Subsolidus relations along the join hedenbergite-ferrosilite. Am. J. Sci. 267 A, 295–324 (1969)

    Google Scholar 

  • MacGregor, I. D.: The system MgO-Al2O3-SiO2; Solubility of Al2O3 in enstatite for spinel- and garnet-peridotite compositions. Am. Mineralogist (in press) (1973)

  • Medaris, L. G., Jr.: High-Pressure peridotites in Southwestern Oregon. Geol. Soc. Am. Bull. 83, 41–58 (1972)

    Google Scholar 

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

    Google Scholar 

  • O'Hara, M. J., Schairer, J. F.: The join diopside-pyrope at atmospheric pressure, Yearbook Carnegie Inst. Wash. 62, 107–115 (1963)

    Google Scholar 

  • Saxena, S. K., Ghose, S.: Mg2+-Fe2+ Order-disorder and the thermodynamics of the orthopyroxene crystalline solution. Am. Mineralogist 56, 532–559 (1971)

    Google Scholar 

  • Skinner, B. J., Boyd, F. R.: Aluminous enstatites. Yearbook Carnegie Inst. Wash. 63, 163–165 (1964)

    Google Scholar 

  • Smith, D.: Stability of iron-rich pyroxene in the system CaSiO3-FeSiO3-MgSiO3. Am. Mineralogist 57, 1413–1428 (1972)

    Google Scholar 

  • Virgo, D., Hafner, S. S.: Fe2+, Mg order-disorder in heated orthopyroxenes. Mineral. Soc. Amer. Spec. Pap. 2, 67–81 (1969)

    Google Scholar 

  • Williams, R. J.: Reaction constants in the system FeO-MgO -SiO2-O2 at 1 atm between 9000 C and 1300° C: Experimental results. Am. J. Sci. 270, 334–360 (1971)

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

Wood, B.J., Banno, S. Garnet-orthopyroxene and orthopyroxene-clinopyroxene relationships in simple and complex systems. Contr. Mineral. and Petrol. 42, 109–124 (1973). https://doi.org/10.1007/BF00371501

Download citation

  • Received:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF00371501

Keywords

Navigation