GSA Annual Meeting in Seattle, Washington, USA - 2017

Paper No. 282-9
Presentation Time: 9:00 AM-6:30 PM

DID PRECIPITATION STARVATION AS INDICATED BY DEPOSITION OF LOESS TERMINATE THE LATE WEICHSELIAN SCANDINAVIAN ICE SHEET IN EAST-CENTRAL SOUTHERN NORWAY DURING THE EARLY HOLOCENE?


DAHL, Svein Olaf1, SKOGLUND, Rannveig Øvrevik2 and NIELSEN, Pål Ringkjøb1, (1)Geography, University of Bergen, Fosswinckelsgate 6, Bergen, 5007, Norway, (2)Geography, University of Bergen, Bergen, 5007, Norway, svein.dahl@uib.no

The deglaciation following the Late Weichselian glacier maximum in east-central southern Norway was characterized by a continuous vertical downwasting of the Scandinavian Ice Sheet. In the last stages this resulted in a series of ice-dammed lakes existing between the last ice remnants at the former ice divide to the south and the main water divide between east-central southern Norway and Trøndelag to the north. Nedre (lower) Glåmsjø was with a length of about 140 km the largest of these ice-dammed lakes, and it was drained just before the Preboreal/Boreal transition.

The occurrence of loess in kettle holes above the level of Nedre Glåmsjø is suggested to indicate a cold and dry regional (winter) climate interrupted by short and wetter phases reflected by deposition of gyttja. Based on AMS 14C-dates from among other remains of Dryas Octopetala, the loess deposition persisted for several hundred years during the late Preboreal. The most likely source area for the loess is large sandur plains north of Rondane, indicating a prevailing W-NW wind direction during the year.

A possible link to the two climatically induced Erdalen Event glacier readvances at Nigardsbreen (Jostedalsbreen) in the inner fjord region of western Norway at the Preboreal/Boreal transition is discussed.