Southwest Scandinavia, 40–15 kyr BP: palaeogeography and environmental change

Abstract

Twelve palaeogeographical reconstructions illustrate environmental changes at the southwest rim of the Scandinavian Ice Sheet 40-15 kyr BP. Synchronised land, sea and glacier configurations are based on the lithostratigraphy of tills and intertill sediments. Dating is provided by optically stimulated luminescence and calibrated accelerator mass spectrometry radiocarbon.An interstadial sequence ca. 40-30 kyr BP with boreo-arctic proglacial fjords and subarctic flora and occasional glaciation in the Baltic was succeeded by a Last Glacial Maximum sequence ca. 30-20 kyr BP, with the closure of fjords and subsequent ice streams in glacial lake basins in Kattegat and the Baltic. Steadily flowing ice from Sweden bordered the Norwegian Channel Ice Stream. A deglaciation sequence ca. 20-15 kyr BP indicates the transgression of arctic waters, retreat of the Swedish ice and advance of Baltic ice streams succeeded by a return to interstadial conditions. When ameliorated ice-free conditions prevailed in maritime regions, glaciers advanced through the Baltic and when interstadial regimes dominated the Baltic, glaciers expanded off the Norwegian coast. The largest glacier extent was reached in the North Sea around 29 kyr BP, about 22 kyr BP in Denmark and ca. 18 kyr BP in the Baltic. Our model provides new data for future numerical and qualitative landform-based models.

Age and sedimentological features of fluvial series in the Toruń Basin and the Drwęca Valley (Poland)

“…The till fabric data show the north ice flow direction in the area of the Toruń Basin. The chronostratigraphic position of the lower till from Zielonczyn corresponds with the Klintholm Till Unit (Houmark-Nielsen, 2007;Houmark-Nielsen and Kjaer, 2003). In accordance with the suggestions of Houmark-Nielsen (2010) and Marks (2010) the Klintholm ice advance might have reached the northern part of Poland.…”

Substratum morphology and significance during the Weichselian Odra ice lobe advance in northeast Germany and northwest Poland

“…The reconstructed broadly trough-shaped the Odra lobe substratum seems to have been favourable for the advancing ice margin in providing a potentially perfect output area for the fast-flowing ice which filled the Baltic basin. Similar topographic conditions occurred over Denmark where the ice stream advance was guided by topographic depressions (Houmark-Nielsen & Kjaer, 2003). It seems to be clear that in the study area the ice used local topography and eventually it became entrenched and followed a topographic low.…”

“…The concept proposed was further developed including evidence and timing of ice stream activity in the area (e.g., Jørgensen & Piotrowski, 2003;Houmark-Nielsen, 2003;Houmark-Nielsen & Kjaer, 2003;Wysota, 2007;Przybylski, 2008;Kalm, 2012;Lasberg & Kalm, 2013).…”

Timing of massive ‘Fleuve Manche’ discharges over the last 350kyr: insights into the European ice-sheet oscillations and the European drainage network from MIS 10 to 2

“…18.3 ka occurred at time of important environmental changes in the north and north-western British ice margin (Knutz et al, 2002a;Knutz et al, 2002b;Wilson et al, 2002;Hall et al, 2006), contemporaneous with the maximum decay of the FIS (Svendsen et al, 1996;Kleiber et al, 2000;Vorren and Plassen, 2002;Dahlgren and Vorren, 2003;Nygard et al, 2004;Lekens et al, 2005;Knies et al, 2007;Rinterknetch et al, 2007;Goehring et al, 2008), reinforcing the idea that the 'Fleuve Manche' activity was strongly dependent on the surrounding ice-sheet runoff. As a result, the 'Fleuve Manche' was a glacially-fed river and the Bay of Biscay was a depocentre for the European ice sheets erosional products, whose accumulations are still widely visible all along the southern margins of the past FIS (Eissmann, 2002;Houmark-Nielsen and Kjaer, 2003; and BIIS (Eyles and McCabe, 1989;Bowen et al, 2002;Evans and O'Cofaigh, 2003). Because Late Weichselian ice sheets never reached the English Channel area (Ehlers and Gibbard, 2004), we conclude that the Rhine-Thames drainage, which was a conduit for sediment-laden meltwater from the BIIS, FIS and the Alpine glaciers, flowed via the Dover Strait into the Bay of Biscay at the end of the last glacial period, confirming previous proposals by Gibbard (1988) and Busschers et al (2007).…”