Hostname: page-component-78c5997874-lj6df Total loading time: 0 Render date: 2024-11-05T11:51:45.608Z Has data issue: false hasContentIssue false

Crystallization trends of pyroxenes from agpaitic phonolites (Cantal, France)

Published online by Cambridge University Press:  05 July 2018

R. Brousse
Affiliation:
Laboratoire de Pétrographie-Volcanologie, Université Paris XI, 91405 Orsay, France
J. Ph. Rançon
Affiliation:
Bureau de Recherches Géologiques et Miniéres, Départment Géothermie, BP 6009, 45060 Orléans Cédex, France

Abstract

Ca- and Na-rich pyroxene compositions of four agpaitic phonolites from the Cantal Volcano (France) have been studied. The pyroxenes from each sample show a range of compositions between X2+ pyroxencs (with X = Ca, Mg, Fe2+) and aegirine. The main substitution, X2+ by (Fe3+ + Na+), occurs when Na-Mg = 0.5, by which time Si is already equal to 2.0. The crystallization of Fe-Na-rich pyroxenes seems to be related to the increasing peralkalinity of the environment, in which the initially high temperature was suddenly reduced. Other factors, such as the structure of the liquid, are also considered.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1984

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

Abbott, M. J. (1969) Contrib. Mineral. Petrol. 20, 115–34.CrossRefGoogle Scholar
Aoki, K. (1964) Am. Mineral. 49, 1199–223.Google Scholar
Azambre, B., and Girod, M. (1966) Bull. Soc. Fr. Mineral. Cristallogr. 89, 514–20.Google Scholar
Bailey, D. K. (1969) Am. J. Sci. 267-A, 116.CrossRefGoogle Scholar
Baker, I. (1969) Bull. Geol. Soc. Am. 80, 1283–1310.CrossRefGoogle Scholar
Baubron, J. C., Demange, J., and Varet, J. (1977) 5th Reun. Ann. Sci. Terre. Rennes, France.Google Scholar
Brousse, R. (1971) Symp. Jung. p. 337. Annales Hebert, Paris.Google Scholar
Brousse, R. et al. (1972) Geological Map ofRiom es Montagnes, 1/50000. BRGM.Google Scholar
Bussen, I. V., and Sakharov, A. S. (1972) Nauka, Leningrad (in Russian), 1296.Google Scholar
Carmichael, I. S. E. (1962) Mineral. Mag. 33, 86113.Google Scholar
Cawthorn, R. G., and Collerson, K. D. (1974) Am. Mineral. 59, 1203–8.Google Scholar
Edgar, A. D. (1974) Mineral. Mag. 39, 729–30.CrossRefGoogle Scholar
Ernst, W. G. (1962) J. Geol. 70, 689–836.CrossRefGoogle Scholar
Ernst, W. G. (1968) Amphiboles. Springer, 125 pp.CrossRefGoogle Scholar
Ferguson, A. K. (1977a) Contrib. Mineral. Petrol. 60, 247–53.CrossRefGoogle Scholar
Ferguson, A. K. (1977b) J. Geol. Soc. Austral. 24, 491–4.CrossRefGoogle Scholar
Ferguson, A. K. (1978) Contrib. Mineral. Petrol. 67, 11–15.CrossRefGoogle Scholar
Flower, M. F. J. (1974) Am. Mineral. 59, 536–48.Google Scholar
Gerassimovsky, V. I. (1956) Geochemistry. 5, 61–74.Google Scholar
Gerassimovsky, V. I. (1968) 23rd Intern. Geol. Cong. Prague, 6, 259.Google Scholar
Gilbert, M. C. (1969) Am. J. Sci. 267–A, 145–59.Google Scholar
Gomes, C. de B., Moro, S. L., and Dutra, C. V. (1970) Am. Mineral. 55, 224–30.Google Scholar
Hamilton, D. L. (1961) J. Geol. 69, 321–9.CrossRefGoogle Scholar
Kushiro, I. (1962) Japan. J. Geol. Geog. 33, 213–20.Google Scholar
Kushiro, I. (1976) J. Geophys. Res. 81, 6347–50.CrossRefGoogle Scholar
Larsen, L. M. (1976) J. Petrol. 17, 258–90.CrossRefGoogle Scholar
Larsen, L. M. and Steenfelt, A. (1974) Lithos. 7, 81–90.CrossRefGoogle Scholar
Le Maitre, R. W. (1962) Bull. Geol. Soc. Am. 73, 1309–40.CrossRefGoogle Scholar
Maury, R. (1976) Thesis, Univ. Paris XI, 455 pp.Google Scholar
Mysen, B. O., and Virgo, D. (1978) Am. J. Sci. 278, 1307–22.CrossRefGoogle Scholar
Nicholls, J., and Carmichael, I. S. E. (1969) Schweiz. Mineral. Petrogr. Mitt. 49, 47–64.Google Scholar
Nielsen, T. F. D. (1979) Contrib. Mineral. Petrol. 69, 234–44.CrossRefGoogle Scholar
Noble, D. C. (1970) Bull. Geol. Soc. Am. 81, 2677–88.CrossRefGoogle Scholar
Noble, D. C., Smith, V. C., and Peck, L. C. (1967) Geochim. Cosmochim. Ada. 31, 215–23.CrossRefGoogle Scholar
Nolan, J. (1969) Mineral. Mag. 37, 216–29.CrossRefGoogle Scholar
Pedersen, A. K., Engell, J., and Ronsbo, J. G. (1975) Lithos. 8, 255–68.CrossRefGoogle Scholar
Powell, M., and Powell, R. (1977) Contrib. Mineral. Petrol. 62, 193–204.CrossRefGoogle Scholar
Powell, R. (1978) Phil. Trans. R. Soc. London, 288, 457–69.Google Scholar
Ronsbo, J. G., Pedersen, A. K., and Engell, J. (1977) Lithos. 10, 193–204.CrossRefGoogle Scholar
Rossi, G. (1978) Contrib. Mineral. Petrol. 66, 109.CrossRefGoogle Scholar
Roux, J. (1979) Thesis, Univ. Paris XI, 46 pp.Google Scholar
Scott, P. W. (1976) Mineral. Mag. 40, 805–16.CrossRefGoogle Scholar
Sorensen, H. (1974) The Alkaline Rocks, John Wiley and Sons, 622 pp.Google Scholar
Stephenson, D. (1972) Lithos. 5, 187–201.CrossRefGoogle Scholar
Sutherland, D. S. (1974) Bull. Vole. 38, 517–47.CrossRefGoogle Scholar
Varet, J. (1967) 3rd cycle thesis, Univ. Paris XI, 354 pp. (1968) Bull. Vole. 33, 621–56.CrossRefGoogle Scholar
Yagi, K. (1953) Bull. Geol. Soc. Am. 64, 769–810.CrossRefGoogle Scholar
Yagi, K. (1958) J. Mineral. Soc. Japan. 3, 763–9.Google Scholar
Yagi, K. (1966) Am. Mineral. 51, 976–1000.Google Scholar