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Lookup NU author(s): Professor Rachel Carr
This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).
© 2024 The Author(s). Boreas published by John Wiley & Sons Ltd on behalf of The Boreas Collegium. Here we present the first Lateglacial and Holocene glacial history from Rotsunddalen, northern Troms and western Finnmark county, northern Norway, based on both relative and numerical moraine dating using Schmidt hammer, soil chronosequencing and terrestrial cosmogenic nuclide dating. We combine these chronological data with a regional map of the glacial geomorphology to hypothesize key events in the glacial history from around 14 ka to present. Our reconstruction shows that, following deglaciation of the main ice sheet across central Troms and Finnmark, mountain glaciers were terminating on land, close to the coast, between around 12.1 and 10.6 ka. Continued recession of the main Fennoscandian Ice Sheet margin towards the SE led to the isolation of several large plateau icefields and outlet glaciers that generated moraines at around 10.2–9.2 ka, which we ascribe to the Erdalen Event, and 8.4–8.2 ka, which is broadly contemporaneous with the 8.2 ka cold event. Although the latter corresponds with the Scandinavian Finse Event, very few moraines have been dated to this time and we therefore view it as a tentative hypothesis for future work to test. During the Holocene Thermal Maximum (~6.6 to 6.3 ka) most (if not all) glaciers in the region disappeared, but then regrew during the Neoglaciation and produced large moraines dated to around 4.7 ka that lie a few hundred metres distal to the prominent Little Ice Age moraines (previously dated to AD 1810s–1870s). Given the limitations of our dating approach, the preservation of moraines dated to this period in northern Norway also warrants further investigation. We also highlight that terrestrial cosmogenic nuclide dating of the moraines is not consistent with other dating approaches and the widely established deglaciation history of the region, probably owing to cosmogenic inheritance and insufficient glacial erosion.
Author(s): Leigh JR, Jones RS, Stokes CR, Evans DJA, Carr JR, Andreassen LM
Publication type: Article
Publication status: Published
Journal: Boreas
Year: 2024
Volume: 53
Issue: 4
Pages: 619-654
Print publication date: 01/10/2024
Online publication date: 12/06/2024
Acceptance date: 14/05/2024
Date deposited: 24/06/2024
ISSN (print): 0300-9483
ISSN (electronic): 1502-3885
Publisher: John Wiley and Sons Inc.
URL: https://doi.org/10.1111/bor.12668
DOI: 10.1111/bor.12668
Data Access Statement: The glacial geomorphological mapping is published in Leigh et al. (2021) and is also available on request to the corresponding author. The raw data from the Schmidt hammer dating, soil chronosequencing and terrestrial cosmogenic nuclide dating are available in the paper or from the corresponding author upon request.
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