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Late-Holocene environment and climatic changes in Ameralik Fjord, southwest Greenland: evidence from the sedimentary record

Møller, H. S., Jensen, K. G., Kuijpers, A., Aagaard-Sørensen, S., Seidenkrantz, M.-S., Prins, M., Endler, R., Mikkelsen, N.
TheHolocene 2006 v.16 no.5 pp. 685-695
Bacillariophyceae, Retaria, climate, climate change, fauna, gravity, ice, radiocarbon dating, sedimentation rate, sediments, snowmelt, winter, Atlantic Ocean, Greenland
Sedimentological and geochemical (XRF) data together with information from diatom and benthic foraminiferal records of a 3.5 m long gravity core from Ameralik Fjord, southern West Greenland, is used for reconstructing late-Holocene environmental changes in this area. The changes are linked to large-scale North Atlantic ocean and climate variability. AMS ¹⁴C-dating of benthic foraminifera indicates that the sediment core records the last 4400 years and covers the termination of the Holocene Thermal Maximum (HTM). The late HTM (4.4-3.2 ka BP) is characterized by high accumulation rates of fine (silty) sediments related to strong meltwater discharge from the Inland Ice. The HTM benthic foraminiferal fauna demonstrates the presence of well-ventilated, saline bottom water originating from inflow of subsurface West Greenland Current water of Atlantic (Irminger Sea) origin. The hydrographic conditions were further characterized by limited sea ice probably related to a mild and relatively windy winter climate. After 3.2 ka BP lower fine-grained sedimentation rates, but a larger input from sea-ice rafted or aeolian coarse material prevailed. This can be related to colder atmospheric conditions with a decreased meltwater discharge and more widespread sea-ice cover in the fjord.