Holocene sedimentary environment of a High-Arctic fjord in Nordaustlandet, Svalbard

A 2.5-metre-long marine core from Isvika bay in Nordaustlandet (80 degrees N, 18 degrees E) was AMS C-14 dated and analysed for its sedimentological and magnetic parameters. The studied record was found to cover the entire Holocene and indicates major turnovers in the palaeo-hydrography and sedimentary depositional history. The area was deglaciated at around 11,300 BP. The early Holocene has indications of rapid melting of glaciers and frequent deposition of ice-rafted debris (IRD). The climatic optimum terminated with a probable glacier re-advance event occurring ca. 5800 cal BP. This event caused the deposition of a diamicton unit in Isvika bay, followed by a shift towards a colder and a more stratified hydrographic setting. The reduction in IRD indicates gradual cooling, which led to the stratification of the bay and eventually to more persistent fast sea-ice conditions by 2500 cal BP. For the last 500 years, Isvika has again been seasonally open.