Luminescence signals from modern sediments in a glaciated bay, NW Svalbard
Landforming processes are highly active in the Arctic, and luminescence dating can be used to establish a chronological framework for these processes. For example, luminescence ages of raised littoral and marine deposits provide the age control for many reconstructions of Pleistocene events in the A...
Published in: | Quaternary Geochronology |
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ftulundlup:oai:lup.lub.lu.se:e0d36ad1-ec7b-4169-8b7f-f73341eb3a8b 2023-05-15T14:54:22+02:00 Luminescence signals from modern sediments in a glaciated bay, NW Svalbard Alexanderson, Helena Murray, Andrew S. 2012 https://lup.lub.lu.se/record/3069035 https://doi.org/10.1016/j.quageo.2012.01.001 eng eng Elsevier https://lup.lub.lu.se/record/3069035 http://dx.doi.org/10.1016/j.quageo.2012.01.001 wos:000307195300039 scopus:84863785478 Quaternary Geochronology; 10, pp 250-256 (2012) ISSN: 1871-1014 Geology Luminescence dating Modern sediments Bleaching Glacial Arctic Svalbard contributiontojournal/article info:eu-repo/semantics/article text 2012 ftulundlup https://doi.org/10.1016/j.quageo.2012.01.001 2023-02-01T23:35:38Z Landforming processes are highly active in the Arctic, and luminescence dating can be used to establish a chronological framework for these processes. For example, luminescence ages of raised littoral and marine deposits provide the age control for many reconstructions of Pleistocene events in the Arctic. Due to the nature of the depositional environment (e.g. short transport distance, turbid water, long polar night) these types of sediment may not be completely zeroed at the time of deposition. To test the significance of incomplete bleaching in this type of environment, surface sediments were sampled along a transect from the margin of a glacier out into a nearby bay on NW Svalbard. The water in the bay is very turbid (secchi depth 0.1 m), but there is significant reworking by waves along the shores. Quartz optically stimulated luminescence (OSL) and feldspar infrared stimulated luminescence (IRSL) were measured using sand-sized grains. For quartz OSL and feldspar IRSL (50 degrees C) the ice-proximal sample showed relatively high doses (similar to 12 Gy) while nearby beach sand and shallow-marine deposits, as well as ice-distal sandur sediments, had much lower doses: most OSL doses were consistent with zero, while IRSL (50 degrees C) ranged from 0.5 to 6.5 Gy. Post-IR IRSL (290 degrees C) doses were overall much higher (similar to 20-55 Gy), which partly is due to a significant (similar to 12 Gy) unbleachable residual, and partly due to slower bleaching rates than for the IRSL (50 degrees C) signal. In this Arctic environment it appears that bleaching is limited in the first similar to 100 m of meltwater transport from the glacier margin, but for material transported at least 3 km bleaching of OSL and IRSL (50 degrees C) signals is more or less complete. Given the very limited light penetration through the seawater in the bay, any bleaching must have occurred during fluvial/subaerial transport to the bay or by wave-reworking on the beach. Apart from the ice-proximal glacifluvial sediments, residual apparent ... Article in Journal/Newspaper Arctic glacier polar night Svalbard Lund University Publications (LUP) Arctic Svalbard Quaternary Geochronology 10 250 256 |
institution |
Open Polar |
collection |
Lund University Publications (LUP) |
op_collection_id |
ftulundlup |
language |
English |
topic |
Geology Luminescence dating Modern sediments Bleaching Glacial Arctic Svalbard |
spellingShingle |
Geology Luminescence dating Modern sediments Bleaching Glacial Arctic Svalbard Alexanderson, Helena Murray, Andrew S. Luminescence signals from modern sediments in a glaciated bay, NW Svalbard |
topic_facet |
Geology Luminescence dating Modern sediments Bleaching Glacial Arctic Svalbard |
description |
Landforming processes are highly active in the Arctic, and luminescence dating can be used to establish a chronological framework for these processes. For example, luminescence ages of raised littoral and marine deposits provide the age control for many reconstructions of Pleistocene events in the Arctic. Due to the nature of the depositional environment (e.g. short transport distance, turbid water, long polar night) these types of sediment may not be completely zeroed at the time of deposition. To test the significance of incomplete bleaching in this type of environment, surface sediments were sampled along a transect from the margin of a glacier out into a nearby bay on NW Svalbard. The water in the bay is very turbid (secchi depth 0.1 m), but there is significant reworking by waves along the shores. Quartz optically stimulated luminescence (OSL) and feldspar infrared stimulated luminescence (IRSL) were measured using sand-sized grains. For quartz OSL and feldspar IRSL (50 degrees C) the ice-proximal sample showed relatively high doses (similar to 12 Gy) while nearby beach sand and shallow-marine deposits, as well as ice-distal sandur sediments, had much lower doses: most OSL doses were consistent with zero, while IRSL (50 degrees C) ranged from 0.5 to 6.5 Gy. Post-IR IRSL (290 degrees C) doses were overall much higher (similar to 20-55 Gy), which partly is due to a significant (similar to 12 Gy) unbleachable residual, and partly due to slower bleaching rates than for the IRSL (50 degrees C) signal. In this Arctic environment it appears that bleaching is limited in the first similar to 100 m of meltwater transport from the glacier margin, but for material transported at least 3 km bleaching of OSL and IRSL (50 degrees C) signals is more or less complete. Given the very limited light penetration through the seawater in the bay, any bleaching must have occurred during fluvial/subaerial transport to the bay or by wave-reworking on the beach. Apart from the ice-proximal glacifluvial sediments, residual apparent ... |
format |
Article in Journal/Newspaper |
author |
Alexanderson, Helena Murray, Andrew S. |
author_facet |
Alexanderson, Helena Murray, Andrew S. |
author_sort |
Alexanderson, Helena |
title |
Luminescence signals from modern sediments in a glaciated bay, NW Svalbard |
title_short |
Luminescence signals from modern sediments in a glaciated bay, NW Svalbard |
title_full |
Luminescence signals from modern sediments in a glaciated bay, NW Svalbard |
title_fullStr |
Luminescence signals from modern sediments in a glaciated bay, NW Svalbard |
title_full_unstemmed |
Luminescence signals from modern sediments in a glaciated bay, NW Svalbard |
title_sort |
luminescence signals from modern sediments in a glaciated bay, nw svalbard |
publisher |
Elsevier |
publishDate |
2012 |
url |
https://lup.lub.lu.se/record/3069035 https://doi.org/10.1016/j.quageo.2012.01.001 |
geographic |
Arctic Svalbard |
geographic_facet |
Arctic Svalbard |
genre |
Arctic glacier polar night Svalbard |
genre_facet |
Arctic glacier polar night Svalbard |
op_source |
Quaternary Geochronology; 10, pp 250-256 (2012) ISSN: 1871-1014 |
op_relation |
https://lup.lub.lu.se/record/3069035 http://dx.doi.org/10.1016/j.quageo.2012.01.001 wos:000307195300039 scopus:84863785478 |
op_doi |
https://doi.org/10.1016/j.quageo.2012.01.001 |
container_title |
Quaternary Geochronology |
container_volume |
10 |
container_start_page |
250 |
op_container_end_page |
256 |
_version_ |
1766326091582013440 |