Skip to main content Accessibility help
×
Home

Chemistry and microstructure of orthoamphiboles from cordierite-amphibole rocks at Outokumpu, North Karelia, Finland

  • Peter J. Treloar (a1) and Andrew Putnis (a1)

Abstract

Orthoamphiboles from the cordierite-amphibole-bearing rocks at Outokumpu span a large part of the gedrite-anthophyllite solid-solution series. The amphiboles grew at temperatures near to or just above that of the solvus crest with post-metamorphic cooling resulting in sub-solvus exsolution, the distribution of which is compatible with an asymmetric solvus in which the anthophyllite limb is the steeper. Metamorphic conditions in the area imply that the crest of the solvus is unlikely to be at a temperature in excess of about 600 °C Electron microprobe traverses and Al- scans show that the amphibole compositions vary rapidly both along and across grains. These variations can be explained by varying availability of Na controlling the extent of the edenitic substitution in the solid solution series. In this case this variability in Na availability may be explained by the external control of μ Na through the fluid phase.

Copyright

References

Hide All
Campbell, D. S. (1980) Trans. R. Soc. Edinburgh, 71, 185-200.
Chinner, G. A., and Fox, J. S. (1974) Geol. Mag. 111, 397-408.
Eskola, P. (1933) Bull. Comm. Geol. Finland, 103, 2644.
Gaal, G., Koistinen, T., and Mattila, E. (1975) Bull. Geol. Surv. Finland, 271, 1-67.
Gittos, M. R., Lorimer, G. W., and Champness, P. E. (1976) In Electron Microscopy in Mineralogy, Wenk, H. R. et al. (eds.), Springer-Verlag, Berlin, 238-47.
Huhma, A., and Huhma, M. (1970) Bull. Geol. Soc. Finland, 42, 57-88.
James, R. S., Grieve, R. A. F., and Pauk, L. (1978) Am. J. Sci. 278, 41-63.
Kirby, S. H. (1976) In Electron Microscopy in Mineralogy, Wenk, H. R. et al. (eds.), Springer-Verlag, Berlin, 465-72.
Koistinen, T. J. (1981) Trans. R. Soc. Edinburgh, 72, 115-58.
Makela, M. (1974) Bull. Geol. Surv. Finland, 267, 1-45.
Mikkola, A. (1980) Ibid. 305, 1-22.
Peltola, E. (1978) Econ. Geol. 73, 461-77.
Putnis, A., and McConnell, J. D. C. (1980) Principles of Mineral Behaviour, Blackwells, Oxford.
Robinson, P., and Jaffe, H. W. (1969) Mineral. Soc. Am. Spec. Paper, 2, 251-74.
Robinson, P., Ross, M., and Jaffe, H. W. (1971) Am. Mineral. 56, 1005-41.
Ross, M., Papike, J. J., and Shaw, K. W. (1969) Mineral. Soc. Am. Spec. Paper, 2, 275-99.
Spear, F. S. (1980) Am. Mineral. 65, 1103-18.
Stoddard, E. F. (1979) Geol. Soc. Am. Abs. with Progs., Cordilleran Section 11, 130.
Treloar, P. J., Koistinen, T. J., and Bowes, D. R. (1981) Trans. R. Soc. Edinburgh, 72, 201-15.
Tuominen, H. V., and Mikkola, T. (1950) Bull. Comm. Geol. Finland, 150, 67-92.
Vallance, T. G. (1967) J. Petrol. 8, 84-96.
Veblen, D. R., and Buseck, P. R. (1979) Am. Mineral. 64, 687-700.

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed