Be data from meltwater channels suggest that Jameson Land, east Greenland, was ice-covered during the last glacial maximum |
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| Authors: | Lena Håkansson Jason P Briner Ala Aldahan Göran Possnert |
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| Institution: | aGeological Survey of Denmark and Greenland, Øster Voldgade 10, 1350 Copenhagen-K, Denmark;bDepartment of Geology, University at Buffalo, Buffalo, NY 14260, USA;cDepartment of Earth Sciences, Uppsala University, SE-752 36, Sweden;dDepartment of Geology, United Arab Emirates University, Al Ain, UAE;eTandem Laboratory, Uppsala University, SE-751 21, Sweden |
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| Abstract: | Along the northeast Greenland continental margin, bedrock on interfjord plateaus is highly weathered, whereas rock surfaces in fjord troughs are characterized by glacial scour. Based on the intense bedrock weathering and lack of glacial deposits from the last glaciation, interfjord plateaus have long been thought to be ice-free throughout the last glacial maximum (LGM). In recent years there is growing evidence from shelf and fjord settings that the northeast Greenland continental margin was more extensively glaciated during the LGM than previously thought. However, little is still known from interfjord settings. We present cosmogenic 10Be data from meltwater channels and weathered sandstone outcrops on Jameson Land, an interfjord highland north of Scoresby Sund. The mean exposure age of samples from channel beds (n = 3) constrains on the onset of deglaciation on interior Jameson Land to 18.5 ± 1.3–21.4 ± 1.9 ka (for erosion conditions of 0–10 mm/ka, respectively). This finding adds to growing evidence that the northeast Greenland continental margin was more heavily glaciated during the LGM than previously thought. |
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| Keywords: | Greenland Jameson Land Glaciation Last glacial maximum Cosmogenic isotopes Meltwater channels Sandstone Weathering |
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