Preservation of basal-ice sediment texture in ice-sheet moraines

Ice-sheet moraines near Kangerlussuaq in west Greenland inherit distinctive particle-size distributions from basal ice, although debris structures fro m the basal ice are commonly destroyed by deposition and resedimentation pr ocesses. The abundance of clay and silt in the "dispersed facies" basal ice at the ice-sheet margin is clearly reflected in the sedimentology of the i ce-sheet moraine. Geographical variations in the texture or grain size of m oraine sediments may thus reflect geographical variations in basal ice. Thi s offers a new approach to reconstructing the basal-ice characteristics, an d hence the thermal and dynamic properties, of former ice sheets. (C) 2000 Elsevier Science Ltd. All rights reserved.