Chemistry of Biotites from a Zoned Granitic Pluton in Morocco

A. Mahmood*
Direction de la Géologie, Ministère de l'Energie et des Mines, Rabat, Morocco
*Present address: Department of Geology, Ecole Nationale de l'Industrie Minerale, B.P. 753, Agdal-Rabat, Morocco.

Abstract: Chemical analyses and structural formulae of biotites from the Zaër pluton, a zoned granitic body in the Central Hercynian Massif of Morocco, are presented. The pluton grades from more mafic single-mica granodioritic facies near the margin to more felsic two-mica granitic facies in the central part. There is a relationship between the composition of the biotites and that of the host rocks. Biotite composition in the internal two-mica facies was influenced by a hydrothermal phase.

Mineralogical Magazine; September 1983 v. 47; no. 344; p. 365-369; DOI: 10.1180/minmag.1983.047.344.12
© 1983, The Mineralogical Society
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