2002 Denver Annual Meeting (October 27-30, 2002)

Paper No. 11
Presentation Time: 4:40 PM


MANGERUD, Jan, Dept of Geology, Univ Bergen, Allégt 41, Bergen, N-5007, Norway, LØVLIE, Reidar, Institute of Solid Earth Physics, Univ Bergen, Allégt. 41, Bergen, N-5007, Norway, GULLIKSEN, Steinar, National Lab 14C Dating, Norwegian Univ Sci and Technol, Sem Sælandsv.5, Trondheim, N-7491, Norway, HUFTHAMMER, Anne-Karin, Museum of Zoology, Univ Bergen, Museplass 3, Bergen, N-5020, Norway, LARSEN, Eiliv, Geol Survey of Norway, Trondheim, N-7451, Norway and VALEN, Vidar, Sørlandskonsult AS, Vesterveien 6, Kristiansand, N-4613, Norway, jan.mangerud@geol.uib.no

The paleomagnetic Laschamp (about 41,000 GISP yrs B.P.) and Lake Mungo (about 34,000 GISP yrs B.P.) excursions have been identified in ice-dammed lake sediments in large caves in Western Norway. During both periods the margin of the Scandinavian Ice Sheet advanced and reached the continental shelf beyond the outermost coastline. The mild, 4000 yrs long Ålesund interstade, when the coast and probably much of the hinterland were ice free, separated the two glacial advances.

The two paleomagnetic excursions have also indirectly been identified in the GRIP ice core, Greenland, because weekening of the magnetic field during the excursions caused increased fluxes of 36Cl and 10Be onto the ice sheet. Thus ice margin fluctuations of the Scandinavian Ice Sheet can be correlated with the stratigraphy of GRIP/GISP cores using the paleomagnetic excursions and thus circumventing the application of different dates or time scales. Some of the fluctuations of the Scandinavian Ice Sheet were of the "Allerød/Younger Dryas type" in the sense that it´s margin retreated during mild interstades on Greenland and re-advanced during cold stades. However, some fluctuations were apparently not in phase with the Greenland climate.