Holocene history of Fiskesø, Prinsesse Ingeborg Halvø, eastern North Greenland

Sediment cores up to 92 cm in length were recovered with gravity and Russian peat corers from Fiskesø, Prinsesse Ingeborg Halvø, eastern North Greenland, during the summer 2014. The correlated sediment succession consists of clastic sediments that are interspersed in the upper part with layers of organic material and likely record the environmental history of the lake since deglaciation. The paucity of macrofossil remains hampered radiocarbon dating of the sediments from Fiskesø. According to published data, the deglaciation of the region took place c. 10 cal. ka BP. Relative sea-level reconstructions from the region suggest that the Fiskesø basin, which is today located at 33 m above sea level, was characterised by marine conditions until c. 8.1 cal. ka BP. Marine fossils in the lower part of the sediment succession support the prevalence of marine conditions. A reliable radiocarbon age from 5 cm above the isolation horizon in Fiskesø sediments indicates an age of 6.1 cal. ka BP and supports the isolation of the basin prior to this time. Cooling is indicated in the upper part of the sediment succession and is reported to have taken place in the region stepwise shortly after 6.1 cal. ka BP and at c. 4.5–4.0 cal. ka BP. Despite the poor chronology the data from Fiskesø support existing terrestrial and marine reconstructions from the region.