This chapter summarizes, and repeats without referencing, information presented in preceding chapters. Some of these chapters were written more than 5 years ago and there have been important subsequent changes. A few new ref- erences are therefore cited. This chapter was written also with an eye toward suitability for a Canadian overview volume.
The summary follows the systematics introduced ear- lier, treating all rocks according to the four broad temporal divisions; lower Paleozoic and older rocks, middle Paleozoic rocks, upper Paleozoic rocks, and Mesozoic rocks. The rocks of each temporal division are subdivided into spatial divisions. Thus, the lower Paleozoic and older rocks are separated into the Humber, Dunnage, Gander, Avalon, and Meguma zones and subzones as depicted in Figure 11.1. The middle Paleozoic rocks are separated into belts: Gaspé, Fredericton, Mascarene, Arisaig, Cape Breton, and Annapolis for the mainland; and Clam Bank, Springdale, Cape Ray, Badger, La Poile, Botwood, and Fortune for Newfoundland (Fig. 11.2). The upper Paleozoic rocks define a number of basins, and Mesozoic rocks define graben (Fig. 11.3). A compilation and classification of volcanic rocks for the Canadian Appalachian region is provided for comparisons with other divisions (Fig. 11.4).
The Canadian Appalachians provide an excellent example of an orogen that built up through accretion and eventual continental collision. In this model of a typical Wilson cycle, the Humber Zone is the Appalachian miogeocline or continental margin of Laurentia, and outboard zones are accreted parts of the orogen or suspect terranes. These zones are the fundamental divisions
Figures & Tables
This volume focuses on the highly populated Canadian Appalachian region. The chapter on the East Greenland Caledonides stands alone and there is no attempt to integrate the geological accounts of the two far removed regions. Rocks of the Canadian Appalachian region are described under four broad temporal divisions: lower Paleozoic and older, middle Paleozoic, upper Paleozoic, and Mesozoic. The rocks of these temporal divisions define geographic zones, belts, basins, and graben, respectively. The area is of special interest because so many modern concepts of mountain building are based on Appalachian rocks and structures.