Late glacial and Holocene marine records from the Independence Fjord and Wandel Sea regions, North Greenland

Authors


N. Nørgaard-Pedersen, Geological Survey of Denmark and Greenland, Øster Voldgade 10, DK-1350 Copenhagen K, Denmark.
E-mail: nnp@geus.dk

Abstract

The first marine sediment cores from the unexplored Independence Fjord system and the Wandel Sea, North Greenland, have been investigated to reveal the glacial marine history of the region. Two key sites in the Independence Fjord system, and an earlier analysed site from the Wandel Sea continental slope, off the mouth of Independence Fjord, are presented. The Independence Fjord sites reveal an early Holocene record (10.0–8.9 Kya) of fine-grained reddish muds with calcareous microfossils, dominated by the benthic foraminifera Cassidulina neoteretis. We suggest that a semi-permanent fast ice cover characterized the region in the early Holocene, and that the deeper troughs in the mouth region of the Independence Fjord system were intruded by subsurface Atlantic water. A stiff diamicton, at least 1.3 m thick, with coal and sandstone clasts of mainly local origin, and a 0.5-m-thick Holocene cover, are found in one of the sites. The diamicton is assumed to represent a subglacial till predating the early Holocene sediments (>10 Kya). Shallow seismic records off the mouth of Independence Fjord reveal kilometre-sized troughs with signs of glacial erosion, till deposition and a Holocene glaciomarine deposition. These features could indicate that glacial ice debouching from the Independence Fjord system at some time during the last glacial period extended to the mid-outer Wandel Sea shelf. Data from a high-resolution sediment core previously retrieved from the adjacent Wandel Sea slope indicate that the maximum ice sheet advance in this area culminated about 25–20 Kya.

Ancillary