Reconstructions of sea‐surface conditions during the Holocene were achieved on two sediment cores from the northwest Greenland margin (AMD14‐204) and Kane Basin (AMD14‐Kane2B) based on dinoflagellate cyst assemblages. On the northwest Greenland margin, sea‐surface conditions were cold with an extended sea ice cover prior to 7750 cal a bp associated with the end of the deglaciation. A major change occurred around ca. 7750 cal a bp with enhanced influence of warmer water from the West Greenland Current, and optimal sea‐surface conditions were observed around 6000 cal a bp. After 3350 cal a bp, results reflect the establishment of the modern assemblages. In the Kane Basin, sea‐surface conditions were not favourable for dinocyst productivity prior to 7880 cal a bp, as the basin was still largely covered by ice. The presence of warmer water is recorded between 7880 and 7200 cal a bp and the highest primary productivity between 5200 and 2100 cal a bp, but sea‐surface conditions remained cold with an extended sea ice cover throughout the Holocene. Overall, the results from this study revealed the strong influence of meltwater discharges and oceanic current variability on the sea‐surface conditions. Copyright © 2019 John Wiley & Sons, Ltd.

The northeastern Baffin Bay continental margin, which experiences high sediment accumulation rates, is an excellent location to study Holocene sedimentary variations. However, it is often difficult to obtain reliable chronologies of the sediment archives using traditional methods (δ18O and radiocarbon) due to specific oceanographic conditions (e.g. corrosive bottom waters). Here we propose a chronostratigraphy of three cores collected on the northwestern Greenland margin (AMD14‐204, AMD14‐210 and AMD14‐Kane2B) based on a combination of radiocarbon dating and palaeomagnetic records. Geophysical properties of discrete samples were used to verify the reliability of the palaeomagnetic records. Palaeomagnetic analyses indicate a strong and stable natural remanent magnetization carried by low coercivity ferrimagnetic minerals (magnetite) in the pseudo‐single domain grain size range. Correlation of the full palaeomagnetic vector (inclination, declination, and relative palaeointensity) was used to establish a reliable chronostratigraphical framework for two of the cores (AMD14‐204 and AMD14‐210) and to propose an original palaeomagnetic record for the previously 14C‐dated core AMD14‐Kane2B that covers most of the Holocene. Overall, this new chronostratigraphy allowed improvement of the timing of the main palaeoenvironmental changes that occurred in this area during the Holocene.

The mineralogical and geochemical compositions of three sediment cores from the northwestern Greenland continental margin (AMD14-204 and AMD14-210) and Kane Basin (AMD14-Kane2B) were investigated using quantitative X-ray diffraction and energy-dispersive X-ray fluorescence in order to document the impact of ice-ocean interactions on the sediment provenance and transport pathways during the Holocene. Unmixing of the sediment composition and ratios such as quartz/clays and K/Fe indicate that detrital sediments in cores from the northwest Greenland margin are derived mainly from Prøven granite and reworked Archean gneiss, whereas sediments from Kane Basin are derived mainly from detrital carbonate (Ellesmere Island) and Proterozoic gneiss (Humboldt Glacier). Mineralogical and geochemical signatures also reveal that changes in detrital sediment provenance and transport in the region are strongly interconnected to regional ice stream dynamics, especially during the early Holocene with strong meltwater discharge from the Greenland Ice Sheet associated with the end of deglaciation. With the establishment of milder conditions during the mid-Holocene and reduced glacial activity once ice sheets retreated inland, sediment inputs via ocean currents became more effective. Thus, detrital proxies in core AMD14-204, located in the Upernavik cross-shelf trough, support the hypothesis of an intensification of the West Greenland Current influence after 7.7 cal ka BP, which eventually affected the regional sediment dynamic by a greater contribution from basalt to the sediment supply. Finally, our results suggest that the interactions between climate, glacial dynamics, and surface ocean circulation controlled the paleoenvironmental changes observed in the three cores.

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