Assessing changes in sea surface conditions due to the effects of past freshwater outflow through Baffin Bay and Davis Strait to the Labrador Sea, hereafter referred to as the Baffin Bay corridor, is relevant in understanding the variability in Labrador Sea Water (LSW) formation. Here, regional changes in oceanographic circulation and sea surface conditions are reconstructed based on organic-walled dinoflagellate cyst (dinocyst) assemblages from four cores collected from deep, central sites of the Baffin Bay corridor. All cores exhibit a major shift in dinocyst assemblages since the late glacial period. This shift consists of a change from a polar–subpolar heterotrophic species assemblage tolerating cold and near permanent ice-covered conditions, to assemblages characterized by a higher diversity and the occurrence of phototrophic taxa associated with mild conditions. Sea surface reconstructions from the modern analogue technique display a shift from harsh, quasi-perennial ice cover to warmer summer sea surface temperatures and a seasonal sea ice. South of the Davis Strait sill, this regime shift occurred at ca. 11.9 cal ka BP due to the influence of North Atlantic waters. Baffin Bay, however, remained densely sea ice covered until about 7.4 cal ka BP, when these warmer waters penetrated into Baffin Bay and mixed with the West Greenland Current (WGC). This mixing was facilitated by the retreat of the Greenland and Laurentide Ice Sheet (LIS) margins. A major change in Labrador Sea surface conditions occurred nearly at about the same time (~7.6 cal ka BP) when the strong stratification of surface waters weakened because of the reduction in meltwater supplies from the LIS that allowed winter convection and the inception of LSW formation. All these new records demonstrate large amplitude fluctuations in sea surface conditions tightly controlled by the relative strengths and shifts of the warmer WGC and colder Baffin Island Current.

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Based on quantitative X‐ray diffraction mineralogical analysis of cores HU2008029‐0006/0008 (857‐m water depth) located south of the Davis Strait sill, we seek answers to two questions: (i) the temporal correlation of NW Labrador Shelf Sea Heinrich (H‐) and Baffin Bay detrital carbonate (BBDC) events, and (ii) the provenance of the sediments? A sediment‐unmixing model (SedUnMix) is used to determine provenance variations. Although 12 radiocarbon dates were obtained there were many age reversals and we favour a depth/age model for HU2008029‐0008PC based on correlations to well‐dated neighbouring cores north and south of Davis Strait. We find no correlation between H‐ and BBDC events except for H‐0, which appears to be a broadly synchronous event along the NE Canadian margin and is correlative with an episode of major moraine building along this flank of the Laurentide Ice Sheet. Unmixing of the sediment composition based on six potential glacial source regions indicates that the bulk of the sediment in 0008PC is derived from glacial erosion of West Greenland, but is punctuated by intervals when dolomite‐rich sediments, derived from outcrops north of Baffin Bay, dominate the composition. Estimated dates on these BBDC events are ∼13, 25 and 30–38 cal ka BP.

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