Abstract

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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