Late Pleistocene to early Holocene environmental changes on Store Koldewey, coastal north-east Greenland

• Published in: Polar research 2016-01, Vol.35 (1), p.21912-14
• Main Authors: Klug, Martin, Bennike, Ole, Wagner, Bernd
• Format: Article
• Language: English
• Subjects: Archives & records; Arctic environments; Biogeochemistry; Bulk sampling; Carbon 14; Catchment area; Coasts; Dating; Dating techniques; Decay; deglaciation; Environmental changes; Geochemistry; Geophysical methods; Geophysics; Glaciers; Global positioning systems; GPS; Greenland Ice Sheet; Holocene; Ice; Ice ages; Ice environments; Investigations; Lake basins; Lake catchments; Lake ice; lake sediment; Lake sediments; Lakes; Last Glacial Maximum; Mass spectrometry; Mass spectroscopy; Meltwater; North-east Greenland; Pleistocene; Polar environments; Radiocarbon dating; Radiometric dating; Scientific imaging; Sea level; Sediment; Sediment samples; Sedimentation; Sediments; Snow accumulation; Water analysis
• ISSN: 1751-8369; 0800-0395; 1751-8369
• DOI: 10.3402/polar.v35.21912

A lake sediment sequence from southern Store Koldewey, north-east Greenland, has been investigated using a multidisciplinary approach, including geophysical, geochemical, biogeochemical, biological and sedimentological methods. Chronological constraints are provided by accelerator mass spectrometry (AMS) 14 C dating of bulk sediment and complemented with published water moss ages. The record consists of three major sediment units. Their individual structural, textural, geophysical and geochemical characteristics indicate variable input of sediment and meltwater due to variable proximity of the ice margin and therefore reflect the growth and decay of a local glacier during the late Weichselian. Radiocarbon dating of bulk sediment samples from the lowermost unit gave ages of 42 to 34 calibrated thousand years (cal Ky B.P.) and indicates that this material is redeposited in the lake basin during or after the ice advance at the end of the Pleistocene. Increased meltwater and sediment input from a retreating ice margin following the Younger Dryas is indicated by the occurrence of a sandy to gravely section. Fine-grained and laminated sediments were deposited during the Pleistocene-Holocene transition and indicate calm sedimentation conditions with an ice margin outside of the lake catchment. The reoccurrence of coarse sediments during the early Holocene may indicate increased meltwater input in response to the cold spell at about 9.3 Kya with increased snow accumulation rather than fluctuations of local glaciers. The dating results furthermore show that AMS 14 C dating of bulk sediment samples deposited during glacier decay in High Arctic environments can give problematic ages.