Be-10 ages from central east Greenland constrain the extent of the Greenland ice sheet during the Last Glacial Maximum

摘要

Traditional ice sheet reconstructions have suggested two distinctly different ice sheet regimes along the East Greenland continental margin during the Last Glacial Maximum (LGM): ice to the shelf break south of Scoresby Sund and ice extending no further than to the inner shelf at and north of Scoresby Sund. We report new Be-10 ages from erratic boulders perched at 250 m a.s.l. on the Kap Brewster peninsula at the mouth of Scoresby Sund. The average Be-10 ages, calculated with an assumed maximum erosion rate of 1 cm/ka and no erosion (respectively, 17.3 +/- 2.3 ka and 15.1 +/- 1.7 ka) overlap with a period of increased sediment input to the Scoresby Sund fan (19-15 ka). The results presented here suggest that ice reached at least 250 m a.s.l. at the mouth of Scoresby Sund during the LGM and add to a growing body of evidence indicating that LGM ice extended onto the outer shelf in northeast Greenland. (C) 2007 Elsevier Ltd. All rights reserved.