Degradation of glacial deposits quantified with cosmogenic nuclides, Quartermain Mountains, Antarctica
Abstract Many glacial deposits in the Quartermain Mountains, Antarctica present two apparent contradictions regarding the degradation of unconsolidated deposits. The glacial deposits are up to millions of years old, yet they have maintained their meter‐scale morphology despite the fact that bedrock...
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crwiley:10.1002/esp.2039 2024-06-02T07:57:20+00:00 Degradation of glacial deposits quantified with cosmogenic nuclides, Quartermain Mountains, Antarctica Morgan, Daniel J. Putkonen, Jaakko Balco, Greg Stone, John 2011 http://dx.doi.org/10.1002/esp.2039 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fesp.2039 https://onlinelibrary.wiley.com/doi/pdf/10.1002/esp.2039 en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Earth Surface Processes and Landforms volume 36, issue 2, page 217-228 ISSN 0197-9337 1096-9837 journal-article 2011 crwiley https://doi.org/10.1002/esp.2039 2024-05-03T10:43:41Z Abstract Many glacial deposits in the Quartermain Mountains, Antarctica present two apparent contradictions regarding the degradation of unconsolidated deposits. The glacial deposits are up to millions of years old, yet they have maintained their meter‐scale morphology despite the fact that bedrock and regolith erosion rates in the Quartermain Mountains have been measured at 0·1–4·0 m Ma −1 . Additionally, ground ice persists in some Miocene‐aged soils in the Quartermain Mountains even though modeled and measured sublimation rates of ice in Antarctic soils suggest that without any recharge mechanisms ground ice should sublimate in the upper few meters of soil on the order of 10 3 to 10 5 years. This paper presents results from using the concentration of cosmogenic nuclides beryllium‐10 ( 10 Be) and aluminum‐26 ( 26 Al) in bulk sediment samples from depth profiles of three glacial deposits in the Quartermain Mountains. The measured nuclide concentrations are lower than expected for the known ages of the deposits, erosion alone does not always explain these concentrations, and deflation of the tills by the sublimation of ice coupled with erosion of the overlying till can explain some of the nuclide concentration profiles. The degradation rates that best match the data range 0·7–12 m Ma −1 for sublimation of ice with initial debris concentrations ranging 12–45% and erosion of the overlying till at rates of 0·4–1·2 m Ma −1 . Overturning of the tills by cryoturbation, vertical mixing, or soil creep is not indicated by the cosmogenic nuclide profiles, and degradation appears to be limited to within a few centimeters of the surface. Erosion of these tills without vertical mixing may partially explain how some glacial deposits in the Quartermain Mountains maintain their morphology and contain ground ice close to the surface for millions of years. Copyright © 2010 John Wiley & Sons, Ltd. Article in Journal/Newspaper Antarc* Antarctic Antarctica Wiley Online Library Antarctic Quartermain Mountains ENVELOPE(160.750,160.750,-77.850,-77.850) Earth Surface Processes and Landforms 36 2 217 228 |
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Open Polar |
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Wiley Online Library |
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crwiley |
language |
English |
description |
Abstract Many glacial deposits in the Quartermain Mountains, Antarctica present two apparent contradictions regarding the degradation of unconsolidated deposits. The glacial deposits are up to millions of years old, yet they have maintained their meter‐scale morphology despite the fact that bedrock and regolith erosion rates in the Quartermain Mountains have been measured at 0·1–4·0 m Ma −1 . Additionally, ground ice persists in some Miocene‐aged soils in the Quartermain Mountains even though modeled and measured sublimation rates of ice in Antarctic soils suggest that without any recharge mechanisms ground ice should sublimate in the upper few meters of soil on the order of 10 3 to 10 5 years. This paper presents results from using the concentration of cosmogenic nuclides beryllium‐10 ( 10 Be) and aluminum‐26 ( 26 Al) in bulk sediment samples from depth profiles of three glacial deposits in the Quartermain Mountains. The measured nuclide concentrations are lower than expected for the known ages of the deposits, erosion alone does not always explain these concentrations, and deflation of the tills by the sublimation of ice coupled with erosion of the overlying till can explain some of the nuclide concentration profiles. The degradation rates that best match the data range 0·7–12 m Ma −1 for sublimation of ice with initial debris concentrations ranging 12–45% and erosion of the overlying till at rates of 0·4–1·2 m Ma −1 . Overturning of the tills by cryoturbation, vertical mixing, or soil creep is not indicated by the cosmogenic nuclide profiles, and degradation appears to be limited to within a few centimeters of the surface. Erosion of these tills without vertical mixing may partially explain how some glacial deposits in the Quartermain Mountains maintain their morphology and contain ground ice close to the surface for millions of years. Copyright © 2010 John Wiley & Sons, Ltd. |
format |
Article in Journal/Newspaper |
author |
Morgan, Daniel J. Putkonen, Jaakko Balco, Greg Stone, John |
spellingShingle |
Morgan, Daniel J. Putkonen, Jaakko Balco, Greg Stone, John Degradation of glacial deposits quantified with cosmogenic nuclides, Quartermain Mountains, Antarctica |
author_facet |
Morgan, Daniel J. Putkonen, Jaakko Balco, Greg Stone, John |
author_sort |
Morgan, Daniel J. |
title |
Degradation of glacial deposits quantified with cosmogenic nuclides, Quartermain Mountains, Antarctica |
title_short |
Degradation of glacial deposits quantified with cosmogenic nuclides, Quartermain Mountains, Antarctica |
title_full |
Degradation of glacial deposits quantified with cosmogenic nuclides, Quartermain Mountains, Antarctica |
title_fullStr |
Degradation of glacial deposits quantified with cosmogenic nuclides, Quartermain Mountains, Antarctica |
title_full_unstemmed |
Degradation of glacial deposits quantified with cosmogenic nuclides, Quartermain Mountains, Antarctica |
title_sort |
degradation of glacial deposits quantified with cosmogenic nuclides, quartermain mountains, antarctica |
publisher |
Wiley |
publishDate |
2011 |
url |
http://dx.doi.org/10.1002/esp.2039 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fesp.2039 https://onlinelibrary.wiley.com/doi/pdf/10.1002/esp.2039 |
long_lat |
ENVELOPE(160.750,160.750,-77.850,-77.850) |
geographic |
Antarctic Quartermain Mountains |
geographic_facet |
Antarctic Quartermain Mountains |
genre |
Antarc* Antarctic Antarctica |
genre_facet |
Antarc* Antarctic Antarctica |
op_source |
Earth Surface Processes and Landforms volume 36, issue 2, page 217-228 ISSN 0197-9337 1096-9837 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1002/esp.2039 |
container_title |
Earth Surface Processes and Landforms |
container_volume |
36 |
container_issue |
2 |
container_start_page |
217 |
op_container_end_page |
228 |
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1800740485615058944 |