The deglaciation history of Cape Norton Shaw Inlet (eastern Canadian Arctic Archipelago)

This study presents a geophysical and morphosedimentary framework for the reconstruction of the glacial history of a fjord of Ellesmere Island, the Cape Norton Shaw Inlet. The reconstruction is based on a multimethod approach combining high-resolution swath bathymetry, acoustic sub-bottom profiles, and a dated composite sediment sequence (33BC/05GGC: 01CNS). The presence of at least five grounding-zone wedges and a large cluster of moraines at the inlet entrance suggests a period of glacial stillstands and gradual retreat during the Younger Dryas. A radiocarbon date of 10.4 cal ka BP from the mid-inlet provides a minimum age for the retreat of the Innuitian Ice Sheet during the early Holocene. Mineralogical and geochemical signatures from core 01CNS, along with low sedimentation rate, support the hypothesis of the gradual opening of Nares Strait between 9.6 and 8 cal ka BP. Until 1.9 cal ka BP, coarse-grained sediments rich in plagioclase and K-feldspar suggest a landward retreat of glaciers bordering the inlet. A dense cluster of recessional moraines suggests a readvance into the inlet of Cape Norton Shaw glaciers during the Little Ice Age, when they reached their Holocene maximum extent. Near the modern glacier front, submarine landforms (including mega-scale glacial lineations, crevasse-squeeze ridges, eskers, terminal moraines and retreat moraines) form a complete surge-type assemblage, confirming the surge behavior of Cape Norton Shaw Glacier. The close correspondence between the terminal moraine position and the 1959 CE glacier front indicates that the most recent surge began around 1959 CE, with the glacier reaching its maximum extent between 1959 and 1971 CE.