Block fields in southern Norway: Significance for the Late Weichselian ice sheet

The geographical and altitudinal distribution of block fields and trimlines in southern Norway are
discussed in relation to the vertical extent of the continental ice sheet during the Late Weichselian glacial
maximum. Inferred from these considerations and formerly presented ice-sheet phases for the last
glaciation in southern Norway, a new model on the Late Weichselian ice sheet is presented. This model
indicates a low-gradient, poly-centred ice sheet during maximum glaciation with the ice divide zone
located close to the present main watershed. During the deglaciation, the margin of the ice sheet retreated
to the coast and fjord areas of western Norway. This induced a backward lowering of the ice-sheet
surface, and the culmination zones in areas with low pass-points between eastern and western parts of
southem Norway thus migrated E/SE of the present main watershed. During maximum glaciation the
areas of greatest relative ice thickness were located to the central lowland areas of eastern Norway, to
the Tr√łndelag region, and along the deeper fjords of western Norway.