Major Neoglacial Glacier Expansion Episodes in Southern Norway: Evidences from Moraine Ridge Stratigraphy With14C Dates on Buried Palaeosols and Moss Layers

Abstract

Excavations in the outermost end moraine ridges in front of three Jotunheimen glaciers exposed buried palaeosols and moss layers which were 14C dated. Pre-‘Little Ice Age’ Neoglacial maxima were indicated by 14C dates on various soil organic fractions at Styggedalsbreen and Leirbreen; the most probable dates for these maxima are ca.2700 calendar years B.P. and ca.1300 calendar years B.P. A ‘Little Ice Age’ maximum was confirmed by dates on Sphagnum moss layers at Storbreen. Use of replicate dates, dates on different kinds of organic material and on different fractions of soil organic matter were found useful in assessing the relative accuracy of the datings. It is concluded that the ‘Little Ice Age’ glacier expansion episode was the most extensive in southern Norway, but that in at least two other periods of Neoglacial time, glaciers expanded to similar dimensions. No evidence was found for Neoglacial expansion episodes earlier than ca.3000 14C years B.P. Attention is drawn to the temporal and spatial complexities of Neoglacial glacier fluctuations in the European Alps; although similar complexities are suspected for southern Norway and elsewhere in Scandinavia, doubt is expressed in the ability of current glacial stratigraphic approaches to reconstruct the finer details of a Neoglacial chronology. It is inferred that climatic deteriorations since the Preboreal chronozone have been of no greater magnitude than that of the ‘Little Ice Age’.