Geology of the Canadian Appalachians

Abstract

Abstract The Appalachian orogen in Canada is a northeast-trending belt of upper Precambrian and Paleozoic rocks that were deformed in late Precambrian (Avalonian), Middle Ordovician (Taconian), Devonian (Acadian), and Permian-Carboniferous (Alleghanian) times. The Canadian Appalachians lie southeast of the Canadian Shield and Interior Platform of North America, and the system is bounded to the east by the Atlantic Ocean (Figs. 1 and 2). Toward the southwest, its rocks can be traced through the southeast United States to Alabama. Toward the northeast, its submerged offshore extensions are covered by Mesozoic and Cenozoic sediments of the Atlantic continental margin. Syntheses of the orogen and its offshore extensions in Canada and the United States are keyed to a similar format, using many of the same maps and illustrations for purposes of continuity and clarity. Rocks and structures like those of the Canadian Appalachians reappear on the opposite side of the Atlantic Ocean in the British Caledonides and extend northward to East Greenland and Scandinavia. An overview of the East Greenland Caledonides will be included in the Canadian Appalachian volume, because these rocks are a natural extension of those along the west flank of the Appalachian orogen and because of contiguity with the North American continent. The present stratigraphic and tectonic analysis of rocks of the Canadian Appalachians is based on both a temporal and spatial breakdown. Temporally, its rocks can be subdivided into four broad categories: those of late Precambrian-early Paleozoic age, those of middle Paleozoic age, those of late Paleozoic age, and those of early Mesozoic (Triassic) age.