ABSTRACT During the last glacial period, the Laurentide Ice Sheet (LIS) was the largest terrestrial ice sheet on Earth. Its evolution since the Last Glacial Maximum profoundly influenced Earth's geodynamics and surface processes. Investigating the past dynamics of the LIS provides critical insights into how contemporary ice sheets may respond to ongoing climate change. In this paper, we combine lithostratigraphy, targeted foraminiferal assemblage analysis, and swath bathymetry to reconstruct the early phase of retreat of the LIS margin across the Broughton and Merchants fjord–cross‐shelf–trough systems in southeastern Baffin Island, Canadian Arctic Archipelago. Radiocarbon dates based on mixed foraminiferal assemblages provide a revised deglacial chronology for southeastern Baffin Island. In Broughton Trough, the absence of moraines indicates a continuous retreat without prolonged stabilization until at least 12.9 k cal a BP. However, turbidites preserved in sediment cores record meltwater discharge during glacial retreat. In contrast, the Merchants Ice Flow stabilized on a grounding‐zone wedge (GZW) between the LGM and 12.0 k cal a BP. Within the associated turbidite sequence downflow of the GZW, the transition between the presence of the foraminiferal species Islandiella helenae typically associated with ice‐edge or seasonally open‐water conditions and the absence of ice‐rafted debris suggests the development of an ice shelf during this stabilization phase. Previously reported terrestrial cosmogenic nuclide dates show that the inter‐trough region appears to have deglaciated more rapidly than the adjacent troughs, acting as a transitional zone between the Broughton and Merchants ice flow sectors. When integrated with previously published terrestrial record, these results provide an updated deglaciation history of southeastern Baffin Island.
Belko et al. (2026) studied this question.