Constraining Landscape History and Glacial Erosivity Using Paired Cosmogenic Nuclides in Upernavik, Northwest Greenland
High-latitude landscape evolution processes have the potential to preserve old, relict surfaces through burial by cold-based, nonerosive glacial ice. To investigate landscape history and age in the high Arctic, we analyzed in situ cosmogenic Be(sup 10) and Al (sup 26) in 33 rocks from Upernavik, nor...
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ftnasantrs:oai:casi.ntrs.nasa.gov:20150001449 2023-05-15T15:11:46+02:00 Constraining Landscape History and Glacial Erosivity Using Paired Cosmogenic Nuclides in Upernavik, Northwest Greenland Graly, Joseph A. Corbett, Lee B. Bierman, Paul R. Rood, Dylan H. Neumann, Thomas A. Unclassified, Unlimited, Publicly available July 23, 2013 application/pdf http://hdl.handle.net/2060/20150001449 unknown Document ID: 20150001449 http://hdl.handle.net/2060/20150001449 Copyright, Distribution as joint owner in the copyright CASI Lunar and Planetary Science and Exploration GSFC-E-DAA-TN19590 Geological Society of America Bulletin; 125; 10-Sep; 1539-1553 2013 ftnasantrs 2019-07-21T00:18:46Z High-latitude landscape evolution processes have the potential to preserve old, relict surfaces through burial by cold-based, nonerosive glacial ice. To investigate landscape history and age in the high Arctic, we analyzed in situ cosmogenic Be(sup 10) and Al (sup 26) in 33 rocks from Upernavik, northwest Greenland. We sampled adjacent bedrock-boulder pairs along a 100 km transect at elevations up to 1000 m above sea level. Bedrock samples gave significantly older apparent exposure ages than corresponding boulder samples, and minimum limiting ages increased with elevation. Two-isotope calculations Al(sup26)/B(sup 10) on 20 of the 33 samples yielded minimum limiting exposure durations up to 112 k.y., minimum limiting burial durations up to 900 k.y., and minimum limiting total histories up to 990 k.y. The prevalence of BE(sup 10) and Al(sup 26) inherited from previous periods of exposure, especially in bedrock samples at high elevation, indicates that these areas record long and complex surface exposure histories, including significant periods of burial with little subglacial erosion. The long total histories suggest that these high elevation surfaces were largely preserved beneath cold-based, nonerosive ice or snowfields for at least the latter half of the Quaternary. Because of high concentrations of inherited nuclides, only the six youngest boulder samples appear to record the timing of ice retreat. These six samples suggest deglaciation of the Upernavik coast at 11.3 +/- 0.5 ka (average +/- 1 standard deviation). There is no difference in deglaciation age along the 100 km sample transect, indicating that the ice-marginal position retreated rapidly at rates of approx.120 m yr(sup1). Other/Unknown Material Arctic Greenland Upernavik NASA Technical Reports Server (NTRS) Arctic Greenland |
institution |
Open Polar |
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NASA Technical Reports Server (NTRS) |
op_collection_id |
ftnasantrs |
language |
unknown |
topic |
Lunar and Planetary Science and Exploration |
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Lunar and Planetary Science and Exploration Graly, Joseph A. Corbett, Lee B. Bierman, Paul R. Rood, Dylan H. Neumann, Thomas A. Constraining Landscape History and Glacial Erosivity Using Paired Cosmogenic Nuclides in Upernavik, Northwest Greenland |
topic_facet |
Lunar and Planetary Science and Exploration |
description |
High-latitude landscape evolution processes have the potential to preserve old, relict surfaces through burial by cold-based, nonerosive glacial ice. To investigate landscape history and age in the high Arctic, we analyzed in situ cosmogenic Be(sup 10) and Al (sup 26) in 33 rocks from Upernavik, northwest Greenland. We sampled adjacent bedrock-boulder pairs along a 100 km transect at elevations up to 1000 m above sea level. Bedrock samples gave significantly older apparent exposure ages than corresponding boulder samples, and minimum limiting ages increased with elevation. Two-isotope calculations Al(sup26)/B(sup 10) on 20 of the 33 samples yielded minimum limiting exposure durations up to 112 k.y., minimum limiting burial durations up to 900 k.y., and minimum limiting total histories up to 990 k.y. The prevalence of BE(sup 10) and Al(sup 26) inherited from previous periods of exposure, especially in bedrock samples at high elevation, indicates that these areas record long and complex surface exposure histories, including significant periods of burial with little subglacial erosion. The long total histories suggest that these high elevation surfaces were largely preserved beneath cold-based, nonerosive ice or snowfields for at least the latter half of the Quaternary. Because of high concentrations of inherited nuclides, only the six youngest boulder samples appear to record the timing of ice retreat. These six samples suggest deglaciation of the Upernavik coast at 11.3 +/- 0.5 ka (average +/- 1 standard deviation). There is no difference in deglaciation age along the 100 km sample transect, indicating that the ice-marginal position retreated rapidly at rates of approx.120 m yr(sup1). |
format |
Other/Unknown Material |
author |
Graly, Joseph A. Corbett, Lee B. Bierman, Paul R. Rood, Dylan H. Neumann, Thomas A. |
author_facet |
Graly, Joseph A. Corbett, Lee B. Bierman, Paul R. Rood, Dylan H. Neumann, Thomas A. |
author_sort |
Graly, Joseph A. |
title |
Constraining Landscape History and Glacial Erosivity Using Paired Cosmogenic Nuclides in Upernavik, Northwest Greenland |
title_short |
Constraining Landscape History and Glacial Erosivity Using Paired Cosmogenic Nuclides in Upernavik, Northwest Greenland |
title_full |
Constraining Landscape History and Glacial Erosivity Using Paired Cosmogenic Nuclides in Upernavik, Northwest Greenland |
title_fullStr |
Constraining Landscape History and Glacial Erosivity Using Paired Cosmogenic Nuclides in Upernavik, Northwest Greenland |
title_full_unstemmed |
Constraining Landscape History and Glacial Erosivity Using Paired Cosmogenic Nuclides in Upernavik, Northwest Greenland |
title_sort |
constraining landscape history and glacial erosivity using paired cosmogenic nuclides in upernavik, northwest greenland |
publishDate |
2013 |
url |
http://hdl.handle.net/2060/20150001449 |
op_coverage |
Unclassified, Unlimited, Publicly available |
geographic |
Arctic Greenland |
geographic_facet |
Arctic Greenland |
genre |
Arctic Greenland Upernavik |
genre_facet |
Arctic Greenland Upernavik |
op_source |
CASI |
op_relation |
Document ID: 20150001449 http://hdl.handle.net/2060/20150001449 |
op_rights |
Copyright, Distribution as joint owner in the copyright |
_version_ |
1766342566013304832 |