ABSTRACT

The 2000 km stretch of glaciated terrain between the north coast of Ellesmere Island and the centre of ice recession in Keewatin can be divided into several large concentric zones, each with characteristic ice-marginal and subglacial landform assemblages determined by basal ice thermal conditions. The entire region lies well north of the southern limit of continuous permafrost, which is several hundreds to more than a thousand metres thick and represents the normal interglacial ground temperature for this region. Permafrost either persisted through the last glaciation under continuously cold-based ice patches or, except where submerged, it reformed upon deglaciation, sometimes early in the deglacial cycle under thinning marginal ice. In this chapter, we describe the glacial landsystems that demarcate the former margins of the Laurentide and Innuitian ice sheets in the area located between northern Baffin Island and the Yukon coastal plain, including the Mackenzie Delta region, and between the islands of the Canadian Arctic Archipelago and central Keewatin (Fig. 7.1). We also discuss vying interpretive models of landform genesis.