Hostname: page-component-78c5997874-m6dg7 Total loading time: 0 Render date: 2024-11-19T04:30:33.023Z Has data issue: false hasContentIssue false

High-temperature diffusion of oxygen in synthetic diopside measured by nuclear reaction analysis

Published online by Cambridge University Press:  05 July 2018

L. Pacaud
Affiliation:
Laboratoire d'étude des mécanismes de transfert en géologie, UMR CNRS 5563. Minéralogie, 39 allées Jules Guesde, F-31000 Toulouse, France
J. Ingrin
Affiliation:
Laboratoire d'étude des mécanismes de transfert en géologie, UMR CNRS 5563. Minéralogie, 39 allées Jules Guesde, F-31000 Toulouse, France
O. Jaoul
Affiliation:
Laboratoire d'étude des mécanismes de transfert en géologie, UMR CNRS 5563. Minéralogie, 39 allées Jules Guesde, F-31000 Toulouse, France

Abstract

We have performed O self-diffusion experiments in synthetic diopside single crystals along the b-axis at temperatures ranging from 1473–1643 K, under controlled O partial pressure (10−11–10−2 atm). The 18O tracer diffusion was imposed by solid/gas exchange between 16O in diopside and 18O2-enriched argon-hydrogen-H2O gas mixture. Diffusion profiles of 18O were measured by Nuclear Reaction Analysis 18O (p,α) 15N. The diffusion coefficients are described by , with log D0(m2/s)=−9.2 ± 1.0 and E 310 ± 30 kJ/mol.

Our results are in agreement with Ryerson and McKeegan's (1994) data and Farver's (1989) data along a direction perpendicular to the c direction. Experiments performed in a wide pO2 range show that D is independent of pO2.

We observe no change in the diffusion regime up to 1643 K (i.e. 22 K prior to melting temperature). This result differs from the diffusion study of Ca in diopside by Dimanov and Ingrin (1995), where a strong enhancement of Ca mobility, attributed to an excess disorder in the Ca-sublattice, was observed above 1523 K. We conclude that O diffusion in diopside is not affected by this premelting phenomenon.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1999

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Ando, K. and Oishi, Y. (1983) Effect of ratio of surface area to volume on oxygen self-diffusion coefficients determined for crushed MgO-Al2O3 spinels. J. Amer. Ceram. Soc., 66, C131–2.CrossRefGoogle Scholar
Azough, F. and Freer, R. (1998) An ion microprobe study of cation diffusion in diopside with applications to thermobarometry. Abstract, Mineralogical Society (London) Winter Meeting: Microbeam Techniques in the Geosciences, London, Jan. 1998.Google Scholar
Béjina, F. and Jaoul, O. (1996) Silicon self-diffusion in quartz and diopside measured by nuclear micro-analysis methods. Phys. Earth Planet. Int., 97, 145–62.CrossRefGoogle Scholar
Cawley, J. D. (1984) Oxygen diffusion in alpha alumina. Unpubl. PhD, Case Western Reserve University, 73 pp.Google Scholar
Connolly, C. and Muehlenbachs, K. (1988) Contrasting oxygen diffusion in nepheline, diopside and other silicates and their relevance to isotopic systematics in meteorites. Geochim. Cosmochim. Acta, 52, 1585–91.CrossRefGoogle Scholar
Dimanov, A. and Ingrin, J. (1995) Premelting and high-temperature diffusion of Ca in synthetic diopside: an increase of the cation mobility. Phys. Chem. Min., 22, 437–42.CrossRefGoogle Scholar
Dimanov, A., Jaoul, O. and Sautter, V. (1996) Calcium self-diffusion in natural diopside single crystals. Geochim. Cosmochim. Acta, 60, 21, 4095–106.CrossRefGoogle Scholar
Elphick, S.C., and Graham, C.M., (1988) The effect of hydrogen on oxygen diffusion in quartz: Evidence for fast proton transients? Nature, 335, 243–5.CrossRefGoogle Scholar
Elphick, S.C., and Graham, C.M., (1990) Hydrothermal oxygen diffusion in diopside at 1 kb, 900–1200°C, a comparison with oxygen diffusion in forsterite, and constraints on oxygen isotope disequilibrium in peridotite nodules. Terra Abstr., 7, 72.Google Scholar
Farver, J.R., (1989) Oxygen self-diffusion in diopside with application to cooling rate determinations. Earth Planet. Sci. Lett., 92, 386–96.CrossRefGoogle Scholar
Farver, J.R., and Yund, R.A., (1990) The effect of hydrogen, oxygen and water fugacity on oxygen diffusion in alkali feldspar. Geochim. Cosmochim. Acta, 54, 2953–64.CrossRefGoogle Scholar
Farver, J.R., and Yund, R.A., (1991) Oxygen diffusion in quartz: dependence on temperature and water fugacity. Chem. Geol., 90, 55–70.CrossRefGoogle Scholar
Fiquet, G., Gillet, P. and Richet, P. (1992) Anharmonicity and high-temperature heat capacity of crystals: the examples of CaGeO4, Mg2GeO4 and CaMgGeO4 olivines. Phys. Chem. Min., 18, 469–79.CrossRefGoogle Scholar
Gérard, O. and Jaoul, O. (1989) Oxygen diffusion in San Carlos olivine. J. Geophys. Res., 94, 4119–28.CrossRefGoogle Scholar
Giletti, B.J., (1985) The nature of oxygen transport within minerals in the presence of hydrothermal water and the role of diffusion. Chem. Geol., 53, 197206.CrossRefGoogle Scholar
Giletti, B.J., and Yund, R.A., (1984) Oxygen diffusion in quartz. J. Geophys. Res., 89, 4039–46.CrossRefGoogle Scholar
Huebner, J.S., and Voigt, D.E., (1988) Electrical conductivity of diopside: Evidence for oxygen vacancies. Amer. Mineral., 73, 1235–54.Google Scholar
Ingrin, J., Latrous, K., Doukhan, J.C., and Doukhan, N. (1989) Water in diopside: an electron microscopy and infrared spectroscopy study. Eur. J. Mineral., 1, 327–41.CrossRefGoogle Scholar
Jaoul, O. and Raterron, P. (1994) High-temperature deformation of diopside crystal 3. Influences of pO2 and SiO2 precipitation. J. Geophys. Res., 99, 9423–39.CrossRefGoogle Scholar
Jaoul, O., Froidevaux, C., Durham, W.B., and Michaut, M. (1980) Oxygen self-diffusion in forsterite: implications for the high-temperature creep mechanism. Earth Planet. Sci. Lett., 47, 391–7.CrossRefGoogle Scholar
Jaoul, O., Houlier, B. and Abel, F. (1983) Study of 18O diffusion in magnesium orthosilicate by nuclear microanalysis. J. Geophys. Res., 88, 613–24.CrossRefGoogle Scholar
Jaoul, O., Sautter, V. and Abel, F. (1991) Nuclear microanalysis: a powerful tool for measuring low atomic diffusivity with mineralogical applications. In Diffusion, Atomic Ordering, and Mass Transport: Selected Topics in Geochemistry (Ganguly, J., ed.). Advances in Physical Geochemistry, 8, pp. 198220. Springer-Verlag, Berlin, Heidelbeg, New York.CrossRefGoogle Scholar
L'Hoir, A., Schmaus, D., Cawley, J. and Jaoul, O. (1981) Depth profiling light nuclei in single crystals: a combined nuclear reaction and RBS technique to minimize unwanted channeling effects. Nucl. Inst. Methods, 191, 357–66.CrossRefGoogle Scholar
Reddy, K.P.R., Oh, S.M., Major, L.D. Jr. and Cooper, A.R., (1980) Oxygen diffusion in forsterite. J. Geophys. Res., 85, 322–6.CrossRefGoogle Scholar
Richet, P. and Fiquet, G. (1991) High-temperature heat capacity and premelting of minerals in the system MgO–CaO–Al2O3–SiO2 . J. Geophys. Res., 96, 445–56.CrossRefGoogle Scholar
Richet, P., Ingrin, J., Mysen, B.O., Courtial, P. and Gillet, P. (1994) Premelting effects in minerals: an experimental study. Earth Planet. Sci. Lett., 121, 589600.CrossRefGoogle Scholar
Richet, P., Mysen, B.O., and Ingrin, J. (1998) High-Temperature X-ray diffraction and Raman spectroscopy of diopside and pseudowollastonite. Phys. Chem. Min., 25, 401–14.CrossRefGoogle Scholar
Ryerson, F.J., and McKeegan, K.D., (1994) Determination of oxygen self-diffusion in akermanite, anorthite, diopside, and spinel: Implication for oxygen isotopic anomalies and the thermal histories of Ca-Al-rich inclusions. Geochim. Cosmochim. Acta, 58, 3713–34.CrossRefGoogle Scholar
Sneeringer, M., Hart, S.R., and Shimizu, N. (1984) Strontium and samarium diffusion in diopside. Geochim. Cosmochim. Acta, 48, 1589–608.CrossRefGoogle Scholar
Stocker, R.L., (1978) Influence of oxygen pressure on defect concentrations in olivine with a fixed cationic ratio. Phys. Earth Planet. Inter., 17, 118–29.CrossRefGoogle Scholar
Stocker, R.L., and Smyth, D.M., (1978) Effect of enstatite activity and oxygen partial pressure on the point-defect chemistry of olivine. Phys. Earth Planet. Int., 16, 145–56.CrossRefGoogle Scholar
Weast, R.C., and Astle, M.J., (1979) Handbook of Chemistry and Physics. CRC Press Inc., Boca Raton, Florida.Google Scholar
York, D. (1966) Least-squares fitting of a straight line. Canad. J. Phys., 44, 1079–86.CrossRefGoogle Scholar
Ziegler, J.F. and Biersack, J.P., (1985) The Stopping and Range of Ions in Solids. Pergamon Press, New York.Google Scholar