Since Peach and Horne's pioneer investigation, there has been speculation that ice from Scandinavia reached Shetland during or prior to the last glacial maximum. The evidence for the presence of ice from Scandinavia is scant and unless and until more evidence is forthcoming it is probably simplest to exclude the possibility of Scandinavian glaciation for the following reasons:

• the Dalsetter erratic is undoubtedly derived from the Oslo region but there is no certainty that it is a glacial erratic carried by ice from its source. The block could have been brought to Shetland by Norse settlers.

• despite searches, no other Scandinavian erratics are known from Shetland, aside from the former contents of ship's ballast at two localities. This situation can be contrasted with the Buchan coastal fringe, where around a dozen Norwegian erratics have been recorded.

• the transport of material to the northwest across southern Shetland can be achieved by Shetland ice if the ice shed lies east of south Mainland. Under these circumstances it would be possible to first raft erratic material from Scandinavia on icebergs and then to carry material westwards beneath Shetland ice at a later stage (Ross, 1996)

• unlike Orkney, no shelly tills derived from the erosion of glacimarine sediment has been found on the eastern fringes of Shetland, indicating that ice has not moved across the bed of the northern North Sea to reach Shetland

• a cover of Scandinavian ice can only occur when the Scandinavian ice sheet is sufficiently thick to cross the Norwegian Trench. This implies conditions close to those of glacial maxima when ice on Shetland would also be thick and act to exclude external ice.