Age of the Pomeranian ice-marginal position in northeastern Germany determined by Optically Stimulated Luminescence (OSL) dating of glaciofluvial sediments

作者：Luethgens Christopher; Boese Margot; Preusser Frank

来源：Boreas, 2011, 40(4): 598-615.

DOI：10.1111/j.1502-3885.2011.00211.x

The Pomeranian ice margin is one of the most prominent ice-marginal features of the Weichselian glaciation in northern Europe. Previous results of surface-exposure dating (SED) of this ice margin disagree with established chronologies and ice retreat patterns, i.e. are much younger than previously expected. We crosscheck the age of the Pomeranian ice-marginal position in northeastern Germany using single-grain quartz Optically Stimulated Luminescence (OSL) dating of glaciofluvial sediments. OSL dating indicates an active ice margin between 20.1 +/- 1.6 ka and 19.4 +/- 2.4 ka forming outwash plains attributed to the Pomeranian ice-marginal position. On the basis of these results, we suggest a critical reassessment of previous SED data available for the Pomeranian ice-marginal position within their respective regional geomorphological contexts. From a process-based point of view, SED ages derived from glacigenic boulders document the stabilization of the landscape after melting of dead ice and landscape transformation under periglacial conditions rather than the presence of an ice margin. SED indicates a first phase of boulder stabilization at around 16.4 +/- 0.7 ka, followed by landscape stabilization within the area attributed to the recessional Gerswalder subphase around 15.2 +/- 0.5 ka. A final phase of accumulation of glaciolacustrine and glaciofluvial sediments at around 14.7 +/- 1.0 ka documents the melting of buried dead ice at that time.

• 出版日期2011-10