On the plutonic evolution of the Wesleyville area, Bonavista Bay, Newfoundland
The Wesleyville area is composed of polydeformed gneisses and migmatites cut by a series of granitic plutons and dike suites. Four major episodes of igneous activity are recognized as follows: (1) the emplacement of the garnetiferous Powder Hill Leucogranite, marking the first event; (2) the emplace...
| Published in: | Canadian Journal of Earth Sciences |
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| Main Authors: | , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Canadian Science Publishing
1976
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| Subjects: | |
| Online Access: | http://dx.doi.org/10.1139/e76-162 http://www.nrcresearchpress.com/doi/pdf/10.1139/e76-162 |
| Summary: | The Wesleyville area is composed of polydeformed gneisses and migmatites cut by a series of granitic plutons and dike suites. Four major episodes of igneous activity are recognized as follows: (1) the emplacement of the garnetiferous Powder Hill Leucogranite, marking the first event; (2) the emplacement of the large megacrystic granites of Deadman's Bay and Cape Freels; (3) development of a suite of diabase dikes; and finally, (4) the emplacement of the Newport pluton, a megacrystic granite almost identical in lithology and chemistry to the earlier ones.The country rocks were affected by five deformation episodes, of which the first two and a regional migmatization pre-dated the Powder Hill pluton. These rocks were then deformed by a third episode, and the last two events post-dated all but the diabase dikes and the Newport pluton. A 400 ± 5 m.y. whole-rock isochron date on the Cape Freels indicates that it is Devonian. This also provides a lower age limit on a late fault that apparently truncates the Newport pluton, and which locally forms the junction between the Avalon and Gander Zones. |
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