FLUCTUATIONS OF THE SVALBARD BARENTS-SEA-ICE SHEET DURING THE LAST 150000 YEARS

On Spitsbergen, western Svalbard, three major glacial advances have be en identified during the Weichselian. All three reached the continenta l shelf west of the Svalbard archipelago. Radiocarbon, luminescence an d amino acid dating of interbedded interstadial and interglacial sedim ents indicate that these glacial advances have Early (Isotope Stage 5d ), Middle (Stage 4), and Late Weichselian ages (Stage 2). An additiona l, more local, advance has been dated to Isotope Stage 5b. The Late We ichselian ice sheet expanded across the entire Barents Sea. However, i n the south-western Barents Sea, the Late Weichselian till is the only till above Eemian sediments, indicating that the Early- and Middle We ichselian ice advances were restricted to the Svalbard archipelago and the northern Barents Sea. A major problem with the onshore sites is t he dating of events beyond the range of the radiocarbon method. To ove rcome this, the onshore record has been correlated with marine cores f rom the continental slope and the deep-sea west of Svalbard, where a c hronology has been established by oxygen isotope stratigraphy. Ice raf ted detritus (IRD) was used as the main monitor of glaciation. The IRD record closely mirrors the glaciation history as interpreted from the onshore sections. During the Late Weichselian, the largest IRD peak o ccurred during deglaciation, a pattern also postulated for the earlier events. Given this, the results from the marine cores indicate that t he ages for the first glacial advances during the Weichselian were a f ew thousand years older than interpreted from the onshore stratigraphy . (C) 1998 Elsevier Science Ltd. All rights reserved.