The geomorphic impact of glaciers as indicated by tors in Swedish Lapland (Aurivaara, 68°N)
International audience Abstract Geomorphological investigations carried out on fifteen tor-like features located on the Aurivaara plateau (North Sweden, 68° N) provide new insights in the greatly debated age of these landforms. Erratics and till trapped deep in the tor joints support a pre-Weichseli...
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ftclermontuniv:oai:HAL:hal-00267389v1 2023-05-15T15:12:54+02:00 The geomorphic impact of glaciers as indicated by tors in Swedish Lapland (Aurivaara, 68°N) André, Marie-Françoise Hall, Kevin Laboratoire de Géographie Physique et Environnementale (GEOLAB) Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut Sciences de l'Homme et de la Société (IR SHS UNILIM) Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Université Clermont Auvergne 2017-2020 (UCA 2017-2020 )-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA) 2004 https://hal.science/hal-00267389 en eng HAL CCSD Elsevier hal-00267389 https://hal.science/hal-00267389 ISSN: 0169-555X Geomorphology https://hal.science/hal-00267389 Geomorphology, 2004, 57, pp.403-421 Key words : preglacial weathering tor-like features glacial erosion Scandinavian ice sheet North Sweden info:eu-repo/semantics/article Journal articles 2004 ftclermontuniv 2023-03-29T01:27:29Z International audience Abstract Geomorphological investigations carried out on fifteen tor-like features located on the Aurivaara plateau (North Sweden, 68° N) provide new insights in the greatly debated age of these landforms. Erratics and till trapped deep in the tor joints support a pre-Weichselian age for tor formation. Moreover, the occurrence of various weathering stages in allochtonous material, the joint width up to 1.5 m (requiring long-term weathering), and the frequent association of tors with pediment-like forms, suggest pre-Quaternary tor formation. The juxtaposition of fresh erratics and in situ old weathering features (mushroom rocks, concentrically weathered well-rounded corestones, and grus) indicates a predominantly cold-based regime for the Scandinavian ice sheet, with erratics carried by the overlying moving ice being repeatedly deposited on tor summits during deglaciation phases. The relationships between tors and ice action indicated for the Aurivaara plateau, result in the proposal of a morphodynamical succession of five tor subtypes ranging from the preservation of well-rounded corestones still embedded in grus (suggesting negligible glacial erosion) to the almost complete removal of tor features by ice scouring. A comparison with tors in similar geological and topographical contexts from the unglaciated Dartmoor area allows a tentative evaluation of an average overall glacial erosion of 0-10 meters on the northern Sweden plateaus, in sharp contrast with the 190 m overdeepening of the nearby Torneträsk basin. Thus, this case study of Swedish tors provides additional support to the recent interpretations of relict landscapes in previously glaciated areas and is in accordance with the classical « model » of glacial selective erosion established in the Nordic and Arctic mountains. Article in Journal/Newspaper Arctic Ice Sheet North Sweden Northern Sweden Lapland HAL Clermont Auvergne (Université Blaise Pascal Clermont-Ferrand/Université d'Auvergne) Arctic Torneträsk ENVELOPE(18.861,18.861,68.392,68.392) |
institution |
Open Polar |
collection |
HAL Clermont Auvergne (Université Blaise Pascal Clermont-Ferrand/Université d'Auvergne) |
op_collection_id |
ftclermontuniv |
language |
English |
topic |
Key words : preglacial weathering tor-like features glacial erosion Scandinavian ice sheet North Sweden |
spellingShingle |
Key words : preglacial weathering tor-like features glacial erosion Scandinavian ice sheet North Sweden André, Marie-Françoise Hall, Kevin The geomorphic impact of glaciers as indicated by tors in Swedish Lapland (Aurivaara, 68°N) |
topic_facet |
Key words : preglacial weathering tor-like features glacial erosion Scandinavian ice sheet North Sweden |
description |
International audience Abstract Geomorphological investigations carried out on fifteen tor-like features located on the Aurivaara plateau (North Sweden, 68° N) provide new insights in the greatly debated age of these landforms. Erratics and till trapped deep in the tor joints support a pre-Weichselian age for tor formation. Moreover, the occurrence of various weathering stages in allochtonous material, the joint width up to 1.5 m (requiring long-term weathering), and the frequent association of tors with pediment-like forms, suggest pre-Quaternary tor formation. The juxtaposition of fresh erratics and in situ old weathering features (mushroom rocks, concentrically weathered well-rounded corestones, and grus) indicates a predominantly cold-based regime for the Scandinavian ice sheet, with erratics carried by the overlying moving ice being repeatedly deposited on tor summits during deglaciation phases. The relationships between tors and ice action indicated for the Aurivaara plateau, result in the proposal of a morphodynamical succession of five tor subtypes ranging from the preservation of well-rounded corestones still embedded in grus (suggesting negligible glacial erosion) to the almost complete removal of tor features by ice scouring. A comparison with tors in similar geological and topographical contexts from the unglaciated Dartmoor area allows a tentative evaluation of an average overall glacial erosion of 0-10 meters on the northern Sweden plateaus, in sharp contrast with the 190 m overdeepening of the nearby Torneträsk basin. Thus, this case study of Swedish tors provides additional support to the recent interpretations of relict landscapes in previously glaciated areas and is in accordance with the classical « model » of glacial selective erosion established in the Nordic and Arctic mountains. |
author2 |
Laboratoire de Géographie Physique et Environnementale (GEOLAB) Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut Sciences de l'Homme et de la Société (IR SHS UNILIM) Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Université Clermont Auvergne 2017-2020 (UCA 2017-2020 )-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA) |
format |
Article in Journal/Newspaper |
author |
André, Marie-Françoise Hall, Kevin |
author_facet |
André, Marie-Françoise Hall, Kevin |
author_sort |
André, Marie-Françoise |
title |
The geomorphic impact of glaciers as indicated by tors in Swedish Lapland (Aurivaara, 68°N) |
title_short |
The geomorphic impact of glaciers as indicated by tors in Swedish Lapland (Aurivaara, 68°N) |
title_full |
The geomorphic impact of glaciers as indicated by tors in Swedish Lapland (Aurivaara, 68°N) |
title_fullStr |
The geomorphic impact of glaciers as indicated by tors in Swedish Lapland (Aurivaara, 68°N) |
title_full_unstemmed |
The geomorphic impact of glaciers as indicated by tors in Swedish Lapland (Aurivaara, 68°N) |
title_sort |
geomorphic impact of glaciers as indicated by tors in swedish lapland (aurivaara, 68°n) |
publisher |
HAL CCSD |
publishDate |
2004 |
url |
https://hal.science/hal-00267389 |
long_lat |
ENVELOPE(18.861,18.861,68.392,68.392) |
geographic |
Arctic Torneträsk |
geographic_facet |
Arctic Torneträsk |
genre |
Arctic Ice Sheet North Sweden Northern Sweden Lapland |
genre_facet |
Arctic Ice Sheet North Sweden Northern Sweden Lapland |
op_source |
ISSN: 0169-555X Geomorphology https://hal.science/hal-00267389 Geomorphology, 2004, 57, pp.403-421 |
op_relation |
hal-00267389 https://hal.science/hal-00267389 |
_version_ |
1766343534937374720 |