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标题：Late Pleistocene to early Holocene environmental changes on Store Koldewey, coastal north-east Greenland
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作者：Martin Klug ; Ole Bennike ; Bernd Wagner 等
期刊名称：Polar Research
印刷版ISSN：1751-8369
出版年度：2016
卷号：35
期号：1
页码：21912
DOI：10.3402/polar.v35.21912
语种：English
出版社：Co-Action Publishing
摘要：Abstract 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) ¹⁴C 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 ¹⁴C dating of bulk sediment samples deposited during glacier decay in High Arctic environments can give problematic ages.
关键词：North-east Greenland ; Greenland Ice Sheet ; Last Glacial Maximum ; deglaciation ; lake sediment.