| Summary: | The western Laurentide Ice Sheet (LIS) is known to have experienced complex ice-flow shifts during the last glaciation due to ice divide migration and increasing topographic influence during deglaciation. Several glacial lakes also developed at different elevations during ice margin retreat over the region. However, due to limited field-based studies and surficial mapping, the evolution of the western LIS is still poorly constrained. Improving reconstructions of the western LIS evolution and understanding its net effect on landscapes and surficial sediments can provide important insights into long-term glacial processes, as well as useful knowledge for mineral exploration in glaciated terrains. Furthermore, detailing retreat over this region can help refine continental-scale ice sheet models and help test suggested meltwater drainage pathways to the northwest down the Mackenzie River Valley, which have important implications in paleoclimatology. This research details relative ice-flow chronology and associated till stratigraphy and provides a reconstruction of ice margin retreat and glacial lake positions along a portion of the western LIS situated west of Great Slave Lake, in the Northwest Territories. Relative ice-flow chronology is established using glacial landforms, outcrop-scale ice-flow indicators, as well as till stratigraphic and provenance analyses. Outcrop-scale indicators show a shift in ice-flow direction from an oldest southwestern (230°) flow, to a western (250°) flow, to a final northwestern (305°) flow. This sequence counters the simple westward flow of other studies and suggests a younger rather than older northwestward ice-flow. Lodged boulders and till clast fabrics from till stratigraphic sections across the study area are broadly consistent with the clockwise ice-flow shift up the stratigraphic column. Indicators of northeast provenance include Canadian Shield (igneous and metamorphic) clasts that are in higher proportions than Mesozoic mudrocks and Paleozoic carbonate rocks that underlie ...
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