Wisconsin Glacial Chronology and Relative Sea-level Movements, Narpaing Fiord Broughton Island Area, Eastern Baffin Island, N.W.T.

Abstract

Three distinct glacier advances and four major periods of adjustment of relative land and sea levels are recognized in the Wisconsin age stratigraphic and geomorphologic record of the Northern Cumber-land Peninsula. The coast, which is presently undergoing submergence, is close to an isostatic equilibrium position following rapid land emergence during post-Cockburn time (ca. 8000–1000 BP). Laurentide ice advances during two earlier stades—the Alikdjuak ca. 115 000 BP and the Napiat > 40 000 BP—were more extensive than the Cockburn glacier advances and a positive relationship between ice load and amount of crustal deflection at the ice margin is demonstrated. Computations based on synchronous raised marine features and known extent of the ice load indicate a crustal flexural parameter (α) of > 80 km and perhaps > 135 km for this area. The date of the Alikdjuak stade suggests the time transgressive nature of the early-Wisconsin maximum position of the continental ice sheet margin and supports the hypothesis that continental glaciation may well have originated in the climatically sensitive uplands of the eastern Canadian arctic/sub-arctic.