Metamorphism and metasomatism of rocks of the Moine Series by a dolerite plug in Glenmore, Ardnamurchan (Plate XIX)
Published online by Cambridge University Press: 14 March 2018
Summary
A small dolerite plug in Glenmore, Ardnamurchan, has metamorphosed and partially vitrified the adjacent Moine arkoses up to a distance of 6 ft. from the contact. Chemical analyses show that the glasses produced by the metamorphism have compositions close to the ternary minimum in the system NaAlSi3O8-KAlSi3O8-SiO2, indicating that they were formed by fractional fusion of a lowest-melting composition from the arkose. Alkali metasomatism in the metamorphosed arkoses resulted in an increase of Na2O and a decrease of K2O as the contact with the dolerite is approached, while an associated pelitic horizon shows an increase of K2O content. A review of other examples of thermal metamorphism of quartzo-feldspathic rocks by basic intrusions shows that movements of alkalis are very common in this type of environment, and the possible relations of the metasomatism and the fusion are discussed.
- Type
- Research Article
- Information
- Mineralogical magazine and journal of the Mineralogical Society , Volume 32 , Issue 254 , September 1961 , pp. 866 - 897
- Copyright
- Copyright © The Mineralogical Society of Great Britain and Ireland 1961
References
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