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An Unusual Occurrence of Myrmekite, and its Significance.

Published online by Cambridge University Press:  01 May 2009

Edwin Sherbon Hills
Edwin Sherbon Hills
Affiliation:
(Lecturer in Geology in the University of Melbourne).
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Extract

As early as 1875, Michel-Lévy made what is believed to be the first reference to that intergrowth of plagioclase and vermicular quartz which Sederholm later (1897) named “myrmekite”. In spite of its early recognition and characteristic appearance, however, there was for long no general agreement as to the geological significance or even the exact nature of the intergrowth. It appeared to be confined to the granitoid plutonic and metamorphic rocks, Becke (1913) having categorically stated that it does not occur in “eigentlich vulcanischen Gesteine”, so that it was with interest that the author recently (1932) recorded its occurrence in an Upper Devonian meta-toscanite from Marysville, Victoria. This does not conflict with Becke's statement, since the rock in question has suffered metamorphism by an intrusion of granodiorite, and is therefore not an “eigentlich“ volcanic rock. Nevertheless the mode of occurrence is unique, and the history of the toscanite has been elucidated with sufficient detail to allow one to infer with some accuracy the conditions under which the myrmekite was produced. In the following account, the myrmekite, biotite-quartz-symplektite, and biotite-dactylite in the subjacent granodiorite and neighbouring adamellite bodies, as well as the myrmekite in the meta-toscanite, are described.

Type
Original Articles
Information
Geological Magazine , Volume 70 , Issue 7 , July 1933 , pp. 294 - 301
Copyright
Copyright © Cambridge University Press 1933

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References

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