The Peel Plateau of Northwestern Canada: An Ice-Rich Hummocky Moraine Landscape in Transition

Abstract

The Peel Plateau is a fluvially incised, ice-rich moraine landscape that extends along the eastern margins of the Richardson and Mackenzie Mountains, northwestern Canada. The 24,000 km2 region demarcates the western boundary of the former Laurentide Ice Sheet (LIS). Landscape form and geomorphic processes are strongly conditioned by terrain assemblages produced during the advance and retreat of the LIS and by the large stores of relict late Pleistocene ground ice preserved in permafrost. Holocene fluvial, slope, and thermokarst activity has reshaped this landscape. Fluvial incision of the plateau and an abundance of ground ice favor the development of retrogressive thaw slumps. Recent warming and increasing rainfall have given rise to large, long-lived instances of these thermokarst features. We discuss the morphology, processes, and climate feedbacks that control their development. Thaw slump activity on the Peel Plateau provides insight on the geomorphic processes that are likely to dominate the evolution of ice-rich glacigenic landscapes under rapidly changing climate conditions.