Schmidt-hammer exposure ages from periglacial patterned ground (sorted circles) in Jotunheimen, Norway, and their interpretative problems
Periglacial patterned ground (sorted circles and polygons) along an altitudinal profile at Juvflya in central Jotunheimen, southern Norway, is investigated using Schmidt-hammer exposure-age dating (SHD). The patterned ground surfaces exhibit R-value distributions with platycurtic modes, broad platea...
Published in: | Geografiska Annaler: Series A, Physical Geography |
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Main Authors: | , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
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Wiley
2016
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Online Access: | http://eprints.uwe.ac.uk/30469/ http://eprints.uwe.ac.uk/30469/3/Sorted%20circles%20-%20text%20revision%20after%20reviewer%201%20version%202%20%20PW%20comments%20%281%29.pdf http://eprints.uwe.ac.uk/30469/4/Sorted%20circles%20-%20text%20revision%20after%20reviewer%201%20version%202%20%20PW%20comments%20%281%29.docx https://doi.org/10.1111/geoa.12134 |
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ftuniwestengland:oai:eprints.uwe.ac.uk:30469 2023-05-15T17:57:55+02:00 Schmidt-hammer exposure ages from periglacial patterned ground (sorted circles) in Jotunheimen, Norway, and their interpretative problems Winkler, S. Matthews, J. Mourne, R. Wilson, P. 2016-09 application/pdf application/vnd.openxmlformats-officedocument.wordprocessingml.document http://eprints.uwe.ac.uk/30469/ http://eprints.uwe.ac.uk/30469/3/Sorted%20circles%20-%20text%20revision%20after%20reviewer%201%20version%202%20%20PW%20comments%20%281%29.pdf http://eprints.uwe.ac.uk/30469/4/Sorted%20circles%20-%20text%20revision%20after%20reviewer%201%20version%202%20%20PW%20comments%20%281%29.docx https://doi.org/10.1111/geoa.12134 en eng Wiley http://eprints.uwe.ac.uk/30469/3/Sorted%20circles%20-%20text%20revision%20after%20reviewer%201%20version%202%20%20PW%20comments%20%281%29.pdf http://eprints.uwe.ac.uk/30469/4/Sorted%20circles%20-%20text%20revision%20after%20reviewer%201%20version%202%20%20PW%20comments%20%281%29.docx Winkler, S. , Matthews, J. , Mourne, R. and Wilson, P. (2016) Schmidt-hammer exposure ages from periglacial patterned ground (sorted circles) in Jotunheimen, Norway, and their interpretative problems. Geografiska Annaler: Series A, Physical Geography, 98 (3). pp. 265-285. ISSN 0435-3676 Available from: http://eprints.uwe.ac.uk/30469 all_rights_reserved Article NonPeerReviewed 2016 ftuniwestengland https://doi.org/10.1111/geoa.12134 2020-08-21T16:10:23Z Periglacial patterned ground (sorted circles and polygons) along an altitudinal profile at Juvflya in central Jotunheimen, southern Norway, is investigated using Schmidt-hammer exposure-age dating (SHD). The patterned ground surfaces exhibit R-value distributions with platycurtic modes, broad plateaus, thin tails , and a negative skew. Sample sites located between 1500 and 1925 m a.s.l. indicate a distinct altitudinal gradient of increasing mean R-values towards higher altitudes interpreted as a chronological function. An established regional SHD-calibration curve for Jotunheimen yielded mean boulder exposure ages in the range 6910 ± 510 to 8240 ± 495 years ago. These SHD ages are indicative of the timing of patterned ground formation, representing minimum ages for active boulder upfreezing and maximum ages for the stabilization of boulders in the encircling gutters. Despite uncertainties associated with the calibration curve and the age distribution of the boulders, the early-Holocene age of the patterned ground surfaces, the apparent cessation of major activity during the Holocene Thermal Maximum (HTM) and continuing lack of late-Holocene activity, clarify existing understanding of the process dynamics and palaeoclimatic significance of large-scale sorted patterned ground as an indicator of a permafrost environment. The interpretation of SHD ages from patterned ground surfaces remains challenging, however, owing to their diachronous nature, the potential for a complex history of formation, and the influence of local, non-climatic factors. Article in Journal/Newspaper permafrost University of the West of England, Bristol: UWE Research Repository Norway Geografiska Annaler: Series A, Physical Geography 98 3 265 285 |
institution |
Open Polar |
collection |
University of the West of England, Bristol: UWE Research Repository |
op_collection_id |
ftuniwestengland |
language |
English |
description |
Periglacial patterned ground (sorted circles and polygons) along an altitudinal profile at Juvflya in central Jotunheimen, southern Norway, is investigated using Schmidt-hammer exposure-age dating (SHD). The patterned ground surfaces exhibit R-value distributions with platycurtic modes, broad plateaus, thin tails , and a negative skew. Sample sites located between 1500 and 1925 m a.s.l. indicate a distinct altitudinal gradient of increasing mean R-values towards higher altitudes interpreted as a chronological function. An established regional SHD-calibration curve for Jotunheimen yielded mean boulder exposure ages in the range 6910 ± 510 to 8240 ± 495 years ago. These SHD ages are indicative of the timing of patterned ground formation, representing minimum ages for active boulder upfreezing and maximum ages for the stabilization of boulders in the encircling gutters. Despite uncertainties associated with the calibration curve and the age distribution of the boulders, the early-Holocene age of the patterned ground surfaces, the apparent cessation of major activity during the Holocene Thermal Maximum (HTM) and continuing lack of late-Holocene activity, clarify existing understanding of the process dynamics and palaeoclimatic significance of large-scale sorted patterned ground as an indicator of a permafrost environment. The interpretation of SHD ages from patterned ground surfaces remains challenging, however, owing to their diachronous nature, the potential for a complex history of formation, and the influence of local, non-climatic factors. |
format |
Article in Journal/Newspaper |
author |
Winkler, S. Matthews, J. Mourne, R. Wilson, P. |
spellingShingle |
Winkler, S. Matthews, J. Mourne, R. Wilson, P. Schmidt-hammer exposure ages from periglacial patterned ground (sorted circles) in Jotunheimen, Norway, and their interpretative problems |
author_facet |
Winkler, S. Matthews, J. Mourne, R. Wilson, P. |
author_sort |
Winkler, S. |
title |
Schmidt-hammer exposure ages from periglacial patterned ground (sorted circles) in Jotunheimen, Norway, and their interpretative problems |
title_short |
Schmidt-hammer exposure ages from periglacial patterned ground (sorted circles) in Jotunheimen, Norway, and their interpretative problems |
title_full |
Schmidt-hammer exposure ages from periglacial patterned ground (sorted circles) in Jotunheimen, Norway, and their interpretative problems |
title_fullStr |
Schmidt-hammer exposure ages from periglacial patterned ground (sorted circles) in Jotunheimen, Norway, and their interpretative problems |
title_full_unstemmed |
Schmidt-hammer exposure ages from periglacial patterned ground (sorted circles) in Jotunheimen, Norway, and their interpretative problems |
title_sort |
schmidt-hammer exposure ages from periglacial patterned ground (sorted circles) in jotunheimen, norway, and their interpretative problems |
publisher |
Wiley |
publishDate |
2016 |
url |
http://eprints.uwe.ac.uk/30469/ http://eprints.uwe.ac.uk/30469/3/Sorted%20circles%20-%20text%20revision%20after%20reviewer%201%20version%202%20%20PW%20comments%20%281%29.pdf http://eprints.uwe.ac.uk/30469/4/Sorted%20circles%20-%20text%20revision%20after%20reviewer%201%20version%202%20%20PW%20comments%20%281%29.docx https://doi.org/10.1111/geoa.12134 |
geographic |
Norway |
geographic_facet |
Norway |
genre |
permafrost |
genre_facet |
permafrost |
op_relation |
http://eprints.uwe.ac.uk/30469/3/Sorted%20circles%20-%20text%20revision%20after%20reviewer%201%20version%202%20%20PW%20comments%20%281%29.pdf http://eprints.uwe.ac.uk/30469/4/Sorted%20circles%20-%20text%20revision%20after%20reviewer%201%20version%202%20%20PW%20comments%20%281%29.docx Winkler, S. , Matthews, J. , Mourne, R. and Wilson, P. (2016) Schmidt-hammer exposure ages from periglacial patterned ground (sorted circles) in Jotunheimen, Norway, and their interpretative problems. Geografiska Annaler: Series A, Physical Geography, 98 (3). pp. 265-285. ISSN 0435-3676 Available from: http://eprints.uwe.ac.uk/30469 |
op_rights |
all_rights_reserved |
op_doi |
https://doi.org/10.1111/geoa.12134 |
container_title |
Geografiska Annaler: Series A, Physical Geography |
container_volume |
98 |
container_issue |
3 |
container_start_page |
265 |
op_container_end_page |
285 |
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1766166431100043264 |