Arctic-alpine blockfields in the northern Swedish Scandes: late Quaternary - not Neogene
Autochthonous blockfield mantles may indicate alpine surfaces that have not been glacially eroded. These surfaces may therefore serve as markers against which to determine Quaternary erosion volumes in adjacent glacially eroded sectors. To explore these potential utilities, chemical weathering featu...
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Online Access: | https://lup.lub.lu.se/record/7791177 https://doi.org/10.5194/esurf-2-383-2014 |
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ftulundlup:oai:lup.lub.lu.se:ad8c78a8-b9e7-4e76-8a47-e87ac2335a39 2023-05-15T15:12:43+02:00 Arctic-alpine blockfields in the northern Swedish Scandes: late Quaternary - not Neogene Goodfellow, Bradley Stroeven, A. P. Fabel, D. Fredin, O. Derron, M. -H. Bintanja, R. Caffee, M. W. 2014 https://lup.lub.lu.se/record/7791177 https://doi.org/10.5194/esurf-2-383-2014 eng eng Copernicus GmbH https://lup.lub.lu.se/record/7791177 http://dx.doi.org/10.5194/esurf-2-383-2014 wos:000356874100001 scopus:84941338385 Earth Surface Dynamics; 2(2), pp 383-401 (2014) ISSN: 2196-6311 Earth and Related Environmental Sciences contributiontojournal/article info:eu-repo/semantics/article text 2014 ftulundlup https://doi.org/10.5194/esurf-2-383-2014 2023-02-01T23:26:50Z Autochthonous blockfield mantles may indicate alpine surfaces that have not been glacially eroded. These surfaces may therefore serve as markers against which to determine Quaternary erosion volumes in adjacent glacially eroded sectors. To explore these potential utilities, chemical weathering features, erosion rates, and regolith residence durations of mountain blockfields are investigated in the northern Swedish Scandes. This is done, firstly, by assessing the intensity of regolith chemical weathering along altitudinal transects descending from three blockfield-mantled summits. Clay / silt ratios, secondary mineral assemblages, and imaging of chemical etching of primary mineral grains in fine matrix are each used for this purpose. Secondly, erosion rates and regolith residence durations of two of the summits are inferred from concentrations of in situ-produced cosmogenic Be-10 and Al-26 in quartz at the blockfield surfaces. An interpretative model is adopted that includes temporal variations in nuclide production rates through surface burial by glacial ice and glacial isostasy-induced elevation changes of the blockfield surfaces. Together, our data indicate that these blockfields are not derived from remnants of intensely weathered Neogene weathering profiles, as is commonly considered. Evidence for this interpretation includes minor chemical weathering in each of the three examined blockfields, despite consistent variability according to slope position. In addition, average erosion rates of similar to 16.2 and similar to 6.7 mm ka(-1), calculated for the two blockfield-mantled summits, are low but of sufficient magnitude to remove present blockfield mantles, of up to a few metres in thickness, within a late Quaternary time frame. Hence, blockfield mantles appear to be replenished by regolith formation through, primarily physical, weathering processes that have operated during the Quaternary. The persistence of autochthonous blockfields over multiple glacial-interglacial cycles confirms their importance as key ... Article in Journal/Newspaper Arctic Lund University Publications (LUP) Arctic Earth Surface Dynamics 2 2 383 401 |
institution |
Open Polar |
collection |
Lund University Publications (LUP) |
op_collection_id |
ftulundlup |
language |
English |
topic |
Earth and Related Environmental Sciences |
spellingShingle |
Earth and Related Environmental Sciences Goodfellow, Bradley Stroeven, A. P. Fabel, D. Fredin, O. Derron, M. -H. Bintanja, R. Caffee, M. W. Arctic-alpine blockfields in the northern Swedish Scandes: late Quaternary - not Neogene |
topic_facet |
Earth and Related Environmental Sciences |
description |
Autochthonous blockfield mantles may indicate alpine surfaces that have not been glacially eroded. These surfaces may therefore serve as markers against which to determine Quaternary erosion volumes in adjacent glacially eroded sectors. To explore these potential utilities, chemical weathering features, erosion rates, and regolith residence durations of mountain blockfields are investigated in the northern Swedish Scandes. This is done, firstly, by assessing the intensity of regolith chemical weathering along altitudinal transects descending from three blockfield-mantled summits. Clay / silt ratios, secondary mineral assemblages, and imaging of chemical etching of primary mineral grains in fine matrix are each used for this purpose. Secondly, erosion rates and regolith residence durations of two of the summits are inferred from concentrations of in situ-produced cosmogenic Be-10 and Al-26 in quartz at the blockfield surfaces. An interpretative model is adopted that includes temporal variations in nuclide production rates through surface burial by glacial ice and glacial isostasy-induced elevation changes of the blockfield surfaces. Together, our data indicate that these blockfields are not derived from remnants of intensely weathered Neogene weathering profiles, as is commonly considered. Evidence for this interpretation includes minor chemical weathering in each of the three examined blockfields, despite consistent variability according to slope position. In addition, average erosion rates of similar to 16.2 and similar to 6.7 mm ka(-1), calculated for the two blockfield-mantled summits, are low but of sufficient magnitude to remove present blockfield mantles, of up to a few metres in thickness, within a late Quaternary time frame. Hence, blockfield mantles appear to be replenished by regolith formation through, primarily physical, weathering processes that have operated during the Quaternary. The persistence of autochthonous blockfields over multiple glacial-interglacial cycles confirms their importance as key ... |
format |
Article in Journal/Newspaper |
author |
Goodfellow, Bradley Stroeven, A. P. Fabel, D. Fredin, O. Derron, M. -H. Bintanja, R. Caffee, M. W. |
author_facet |
Goodfellow, Bradley Stroeven, A. P. Fabel, D. Fredin, O. Derron, M. -H. Bintanja, R. Caffee, M. W. |
author_sort |
Goodfellow, Bradley |
title |
Arctic-alpine blockfields in the northern Swedish Scandes: late Quaternary - not Neogene |
title_short |
Arctic-alpine blockfields in the northern Swedish Scandes: late Quaternary - not Neogene |
title_full |
Arctic-alpine blockfields in the northern Swedish Scandes: late Quaternary - not Neogene |
title_fullStr |
Arctic-alpine blockfields in the northern Swedish Scandes: late Quaternary - not Neogene |
title_full_unstemmed |
Arctic-alpine blockfields in the northern Swedish Scandes: late Quaternary - not Neogene |
title_sort |
arctic-alpine blockfields in the northern swedish scandes: late quaternary - not neogene |
publisher |
Copernicus GmbH |
publishDate |
2014 |
url |
https://lup.lub.lu.se/record/7791177 https://doi.org/10.5194/esurf-2-383-2014 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic |
genre_facet |
Arctic |
op_source |
Earth Surface Dynamics; 2(2), pp 383-401 (2014) ISSN: 2196-6311 |
op_relation |
https://lup.lub.lu.se/record/7791177 http://dx.doi.org/10.5194/esurf-2-383-2014 wos:000356874100001 scopus:84941338385 |
op_doi |
https://doi.org/10.5194/esurf-2-383-2014 |
container_title |
Earth Surface Dynamics |
container_volume |
2 |
container_issue |
2 |
container_start_page |
383 |
op_container_end_page |
401 |
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1766343361901363200 |