The Precambrian Gneisses and Supracrestal Rocks of the Western Shore of Kaipokok Bay, Labrador, Newfoundland

Abstract

In the Kaipokok Bay area the amphibolite facies Hopedale Complex is overlain by the English River Greenstones. The Hopedale Complex is formed of gneisses, amphibolites, and associated granites and shows indications of being polycyclic, possibly derived from an older (Aphebian?) granulite facies terrane. The English River Greenstones are a supracrustal sequence of dominantly metavolcanic rocks and are the equivalents of the Aillik series. Hudsonian orogenic effects were superimposed on both rock units and caused locally intense refoliation of the gneisses and the development of a strong foliation in the greenstones. During this orogenic cycle an early period of intense zonal flattening was followed by a more regionally developed folding and weak tectonite fabric development. All of these rocks were cut by later acidic and basic intrusions. The geological history of the area shows a general similarity to that of southwestern Greenland.