Abstract
Samples of two types of natural basalt were equilibrated over a range of oxygen pressures at four different temperatures, and then quenched to room temperature. Except at the lowest temperature, where magnetic crystals formed under the most oxidizing conditions, totally amorphous samples were obtained. The Mössbauer spectra of 45 samples of the quenched basaltic melts were measured at room temperature. The relationship obtained between the oxidation state and oxygen fugacity differs to some extent from those relations previously described in the literature, in not yielding a linear relationship between log(farric/ferrous) and log(fo2). This might indicate a more involved redox process than that described by a simple reaction between oxides and/or the influence of the cation composition in the process of glass formation. An investigation was made of the kinetics of the redox process. For the experimental setup used, redox equilibrium would be reached within three hours. Finally, three naturally quenched basalt glasses were analyzed for comparison; two showed lower oxidation states than previously found in Icelandic rocks.
Similar content being viewed by others
References
G. C. Kennedy, Am. J. Sci. 246 (1948) 529.
J. S. Hubner, in Research Techniques for High Pressure and High Temperature, Ed. G. C. Ulmer (Springer, New York, 1971), p. 123.
R. H. Nafziger, G. D. Ulmer and E. Woermann, in Research Techniques for High Pressure and High Temperature, Ed. G. C. Ulmer (Springer, New York, 1971), p. 9.
R. F. Fudali, Geochim. Cosmochim. Acta 29 (1965) 1063.
C. R. Thornber, P. L. Roeder and J. R. Foster, Geochim. Cosmochim. Acta 44 (1980) 525.
R. Sack, I. Carmichael, M. Rivers and M. Ghiorso, Contrib. Min. Petrol. 75 (1980) 3
B. Spiering and F. Scifert, Contr. Mineral. and Petrol. 90 (1985) 63.
Y. Hsia, R. Liu, J.-F. Jing, U. Gonser and H. Engelmann, Hyperf. Interact. 27 (1986) 409.
B. O. Mysen, F. Scifert and D. Virgo, Am. Mincral. 65 (1980) 867.
I. Kushiro, Am. Mincral. 57 (1972) 1260.
D. Virgo and B. O. Mysen, Phys. Chem. Mincral. 12 (1985) 65.
S. E. Haggerty in Oxide Minerals, Ed. D. Rumble, III (Mincralogical Society of America, Washington D. C., 1976) p. Hg-160.
A microchemical method exists for this analysis: A. D. Wilson, Analyst 85 (1960) 823.
N. Óskarsson, G. E. Sigvaldason, S. Steinthorsson, J. Petrol. 23 (1982) 28.
M. Sato, in Research Techniques for High Pressure and High Temperature, Ed. G. C. Ulmer (Springer, New York, 1971), p. 43.
C. Wivel and S. Mørup, J. Phys. E. Sci. Instrum. 14 (1981) 605.
M. Cukierman and D. R. Uhlmann, J. Geophys. Res. 79 (1974) 1954.
P. L. Rocder and R. F. Emslic, Contr. Mineral. and Petrol. 29 (1970) 275.
T. N. Irvine and W. R. A. Baragar, Can. J. Earth Sci. 8 (1971) 523.
D. M. Christic, I. Carmichacl and C. H. Langmuir, Earth Planct. Sci. Lett. 79 (1986) 397.
Ö. Helgason and S. Mørup, Proc. Int. Conf. on Mössbauer Spectroscopy, Eds. Barb and Tarina, (Bucharest, 1977), p. 243.
Ö. Helgason, S. Steinthorsson, S. Mørup, J. Lipka and J. E. Knudsen, J. de Physique, 37 (1976) C6.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Helgason, Ö., Steinthorsson, S. & Mørup, S. The ferric/ferrous ratio in basalt melts at different oxygen pressures. Hyperfine Interact 45, 287–294 (1989). https://doi.org/10.1007/BF02405890
Issue Date:
DOI: https://doi.org/10.1007/BF02405890