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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