Glacial history of the Spitsbergen archipelago and the problem of a Barents Shelf ice sheet

The popular concept of a Late Weichselian ice sheet covering the Barents Shelf and confluent with the Scandinavian and Russian ice sheets is based primarily on the 6500 B.P. isobase which rises to the east over Spitsbergen, and to the west over Franz Joseph Land. Analysis of uplift curves from the Spitsbergen archipelago shows, however, that the strongest early Holocene uplift occurs over northeastern Spitsbergen and eastern Nordaustlandet, falling both to east and west, and that the centre of uplift migrates to the southeast during the Holocene. Direct evidence of glacier fluctuation indicates an important Billefjorden Stage of glaciation at about 11,000 to 10,000 B.P., part of whose extent can be defined by moraines and by abrupt changes in the marine limit. The dominant ice masses of the Billefjorden Stage seem to have formed over eastern Spitsbergen, Edgeøya, Barentsøya and southern Hinlopenstretet, and it is the decay of this ice mass which is primarily responsible for the pattern of early Holocene uplift. Stratigraphic evidence suggests the absence of an important glacial event at 18,000–20,000 B.P., but an important phase of Spitsbergen-centred glaciation at about 40,000 B.P., and a glacial phase at 80,000–120,000 B.P. It is suggested that many raised beach sequences outside the Billefjorden readvance show an upper sequence related to deglaciation at about 40,000 B.P., and a lower, Holocene sequence related to decay of the Billefjorden ice. The anomalous pattern of late Holocene uplift may be related to restrained rebound produced by regeneration of ice on the main islands of the archipelago and unrestrained rebound on Hopen and Kong Karls Land, which were incapable of sustaining large ice masses of their own. A pattern of LateGlacial climatic circulation which may have produced ice masses on the east coast of Spitsbergen, west coast of Novaya Zemlya and north coast of Russia is suggested. It is also suggested that this pattern of glaciation produced features which have been wrongly interpreted as evidence of a Barents ice sheet.