Work

Ice-burial history and early Holocene thinning of the Scandinavian Ice Sheet at Gaustatoppen, southern Norway

Year: 2025

Type: article

Abstract: This paper explores the glacial history of Gaustatoppen Mountain in southern Norway using cosmogenic nuclide analysis ( in situ 14 C, 26 Al, 10 Be, 21 Ne) from a vertical transect of surface samples and a shallow (1.3 m) bedrock profile. Analysis of in situ 14 C is central to establishing that the entire mountain was buried by the Scandinavian Ice Sheet during the Last Glacial Maximum until rapid thinning (0.4–19 m yr −1 ) at the end of the Younger Dryas isochrone and/or in the Early Holocene. This implies that ice-sheet thinning coincided with rapid retreat from coastal moraines (c. 190 m yr −1 ) and suggests that the ice margin retreated faster inland than former ice-sheet reconstructions suggest. We further deduce that the Scandinavian Ice Sheet expanded to bury Gaustatoppen no later than c. 31–36 ka consistent with regional chronologies. Just below the summit, long-lived cosmogenic nuclide ages cluster at c. 70–80 ka, indicating a pre-Last Glacial Maximum erosional event possibly linked to the penultimate glacial maximum. Using Markov Chain Monte Carlo inversion modelling of cosmogenic 10 Be and 26 Al in a depth profile we constrain the most likely ice burial and erosion history. We find that Gaustatoppen (at 1714 m a.s.l.) was buried by ice for c. 1.3–26.3 % of time since 500 ka, and that the sampled bedrock outcrop eroded c. 2.6–11.8 m within the same period, and with the last 1 m of erosion occurring within the last c. 130–200 kyr. Collectively, these findings provide valuable insights into the dimensions and dynamics of the Scandinavian Ice Sheet during the last glacial period.

Source: Quaternary Science Reviews

DOI: 10.1016/j.quascirev.2025.109409

Authors: Jane Lund Andersen, Nathaniel A. Lifton, Henriette Linge, Finlay Stuart, Jesper Olsen, Vivi K. Pedersen