A Regional Stratigraphic Isochron (ca. 800014C yr B.P.) from Final Deglaciation of Hudson Strait

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Abstract
Sedimentologic, rock-magnetic, and X-ray fluorescence data from two marine sediment cores in Hudson Strait suggest that a red, hematite-rich clay layer was deposited throughout the strait during the final collapse of the Laurentide Ice Sheet in the vicinity of northern Hudson Bay and western Hudson Strait. This layer, which can be recognized by its reddish-pink color (10YR6/2 to 5YR4/2) and relatively high-hematite proportions (low magnetic susceptibility and magnetite-to-hematite ratio), is dated from 8000 to 790014C yr B.P. at both ends of the strait. The Dubawnt Group, a Proterozoic bedrock unit in northern Hudson Bay, is the most likely source of this stratigraphic isochron. In eastern Hudson strait, the recognition of this red unit and other distal glaciomarine sediments from 8400 to 790014C yr B.P. indicates that little sediment from the nearby Labrador Dome reached eastern Hudson Strait during this 500-yr interval. This time interval immediately postdates the Noble Inlet advance, a northward flow of Labrador ice across eastern Hudson Strait onto southern Baffin Island from ca. 8900 to 840014C yr B.P. One explanation for the lack of Labrador sediments is that the northern margin of the Labrador dome was cold-based for up to 500 yr following the Noble Inlet advance.