Paleoceanographic Development in Nordfjord, North East Greenland, During the Mid- and Late Holocene

Abstract

Sediment core HH13-012GC-TUNU, retrieved from Nordfjord, North-East Greenland, has been investigated in order to reconstruct the paleoceanographic development during the mid- and late Holocene. Nordfjord is one of three tributary fjords to Kaiser Franz Joseph Fjord, and Waltershausen Gletcher is located at its head. The fjord system is largely influenced by the Eastern Greenland Current. Most of the paleoceanographic research from fjords in Greenland have been done in the south-east, and south-west, whereas there are very few studies from the north-eastern part. In this study, results from the sediment core HH13-012GC-TUNU are based on benthic foraminiferal assemblages. An age model is established based on two AMS 14C dates, in addition to an assumed age of the uppermost part. From the results, three foraminiferal assemblage zones are established within the last ⁓7800 cal. yr. BP, covering the Holocene Climate Optimum, the Neoglaciation, and the Little Ice Age. The strong dominance of the species Cassidulina reniforme throughout the core indicates that the conditions within Nordfjord have been that of a glaciomarine environment during the last ⁓7800 cal. yr. High relative abundance of Islandiella Helenae indicates that Atlantic Water, and seasonal sea ice conditions influenced the area until ⁓5200 cal. yr. BP. The transition from the Holocene Climate Optimum to the Neoglaciation is marked by an abrupt increase in the cold water species Astrononion Gallowayi, indicating inflow of Arctic Water, combined with higher energy conditions. The last ⁓630 cal. yr. BP is dominated by Elphidium excavatum f. clavata, indicating continued inflow of Arctic Water, combined with seasonal sea ice cover.