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VI.—The Development of Brown Mica from Augite by Reaction with Felspathic Material
Published online by Cambridge University Press: 01 May 2009
Extract
The conversion of augite or hornblende into brown mica appears to take place from three causes:—
1. By crushing of pyroxenic minerals and felspar, as has been observed by Professor Bonney in sundry schists of the Alps.
2. By the intrusion of felspathic material into a rock containing augite or hornblende, as in the Harz, where granite invades diabase, converting the augite into biotite. A similar change has been observed in the gabbro of the Barnavave Mountain, in the Carlingford district, the diallage being wholly or in part replaced by biotite owing to the invasion of granophyric magma. In Sark the intrusion of an aplitic magma into almost pure hornblende has resulted in the formation of biotite.
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References
page 316 note 2 Q.J.G.S., vol. xlix, p. 104Google Scholar.
page 316 note 3 Lossen, K. A.: Congrès Internat. Géol. Comptes Rendues de la 4me session, 1888, p. 184Google Scholar.
page 316 note 4 Sollas, : Trans. Roy. Irish Acad., vol. xxx (1894), p. 477Google Scholar.
page 316 note 5 Bonney, : Q.J.G.S., vol. xlviii, p. 122 et seqGoogle Scholar.
page 317 note 1 Q.J.G.S., vol. liii, p. 405Google Scholar.
page 317 note 2 I am indebted to Professor Bonney for the opportunity of studying these slices, which belong to his collection.