Abstract

The Devonian System in the region bordered by the Canadian Shield, the Arctic Ocean, the Alaska-Yukon border and interior ranges of the Cordillera and the 49th Parallel has been divided into four stratigraphic units corresponding to the Famennian and Frasnian Ages, and very approximately to the Middle and Early Devonian Epochs. The regional palaeogeographic setting is described for each of the intervals in terms, whenever possible, of the location of shoreline, shelf edge, basin and adjacent orogenic belt. The variations in sedimentary facies within each of the areas of deposition are described and related, if possible, to factors influencing the changes. The major transgressions and regressions of the sea are defined and the regional effects of the resultant unconformities are described. Detailed lithologic descriptions and lists of fossils are omitted. The exhaustive use of synonomous stratigraphic names is deliberately avoided in order to present a brief and simple stratigraphic story illustrated on four facies and thickness maps, a pre-Devonian palaeogeologic map and a stratigraphic cross-section drawn between Manitoba and the Alaska border.