Late Wisconsinan glacial and relative sea level history of Amund and Ellef Ringnes Islands, Nunavut, Canada

Amund and Ellef Ringnes islands occupy the northwest Queen Elizabeth Islands, Arctic Canada. This thesis reconstructs the glacial and relative sea level history of the Ringnes Islands, and builds upon previous studies demonstrating that the Late Wisconsinan Innuitian Ice Sheet extended through the alpine and lowland sectors of the eastern and central Queen Elizabeth Islands.; Ice-flow indicators and granite dispersal along eastern Amund Ringnes Island record the inundation of Massey Sound by northwestward flowing trunk ice from Innuitian divides spanning the alpine and lowland sectors of the Queen Elizabeth Islands. Geochemically similar granite erratics occur within a dispersal train that extends from Ellesmere to Meighen islands, which documents a major flow trajectory of the Innuitian Ice Sheet. The interior of Amund Ringnes Island was overridden by granite-free Innuitian ice flowing north from a lowland divide spanning the central Queen Elizabeth Islands. Although Ellef Ringnes Island experienced widespread Late Wisconsinan glaciation, it remains uncertain whether this was due to Innuitian ice flowing north from this lowland divide, or a local ice cap.; Deglaciation of the Ringnes Islands commenced >10 ka BP. From 10 to 9.4 ka BP, trunk ice in Hassel and Massey sounds retreated to northeast Ellef Ringnes and northern Amund Ringnes islands, and from Prince Gustaf Adolf Sea onto western Ellef Ringnes Island. Local ice caps persisted along the coastlines of Ringnes Islands ≥1400 14C years after the initial evacuation of ice from the intervening marine channels. The chronology of final deglaciation of residual ice caps on the Ringnes Islands remains unknown.; Provisional isobases drawn on deglacial shorelines record the diminishing thickness of the Innuitian Ice Sheet, northwestward across the Ringnes Islands. These support the proposal that an ice divide occupied the central Queen Elizabeth Islands. The continuity of the isobases across Amund and Ellef Ringnes islands is consistent with the glacial geologic evidence that suggests Massey and Hassel sounds were occupied by grounded ice during the last glaciation. Parallel isobases across Peary Channel suggest that this grounded ice extended beyond Massey Sound, although their northward deflection, parallel to western Axel Heiberg Island requires that ice thickness was greater on the eastern side of the channel.