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A second occurrence of dalyite and the petrology of some ejected syenite blocks from São Miguel, Azores

Published online by Cambridge University Press:  14 March 2018

J. R. Cann*
Affiliation:
Department of Mineralogy and Petrology, Downing Place, Cambridge1

Summary

Dalyite, K2ZrSi6O15, occurs in the ejected syenite blocks of Serra de Agua de Pau (Lagoa do Fogo), São Miguel, Azores, in an assemblage sanidine-arfvedsonite-quartz-aegirine-fayalite-astrophyllite-dalyite-pyrrhite. Other blocks from the same locality contain biotite-zircon in place of astrophyllite-dalyite. A comparison made between the chemistry of one specimen of each type indicates that they may be related by paraeutectoid fractional crystallization.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1967

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References

Berthois, (L.), 1953. Comun. Serv. Geol. Portugal, vol. 34, pp. 5198.Google Scholar
Cann, (J. R.), 1965. Proc. Geol. Soe. Lond., Session 1964-65, p. 62.Google Scholar
Cann, (J. R.) and Fleet, (S. G.), 1967. Min. Mag., vol. 36, pp. 233241.Google Scholar
Esenwein, (P.), 1928. Zeitsehr. Volc., vol. 12, pp. 108227.Google Scholar
Fleet, (S. G.), 1965. Zeitschr. Krist., vol. 121, pp. 349368.CrossRefGoogle Scholar
Hartung, (G.), 1860. Die Azoren in ihrer äusseren Erscheinung und nach ihrer geognostichen Natur. Leipzig, 1860.CrossRefGoogle Scholar
Mügge, (O.), 1883. Neues Jahrb. Min., Bd. II, p. 189.Google Scholar
Nockolds, (S. R.) and Allen, (R.), 1953. Geochimica Acta, vol. 4, pp. 105142.CrossRefGoogle Scholar
Osann, (A.), 1888. Neues Jahrb. Min., Bd. I, pp. 117-130.Google Scholar
Sabine, (P. A.), 1960. Bull. Geol. Surv. Gt. Britain, No. 16, pp. 156178.Google Scholar
Van Tassel, (R.), 1952. Min. Mag., vol. 29, pp. 850857.Google Scholar
Wager, (L. R.) and Mitchell, (R. L.), 1951. Geochimiea Acta, vol. 1, pp. 129208.CrossRefGoogle Scholar