Optical dating of cobble surfaces determines the chronology of Holocene beach ridges in Greenland
We constrain the age of a cobble beach ridge system in Greenland using Optically Stimulated Luminescence (OSL) dating of buried cobble surfaces. Luminescence signals from six cobbles are measured using infrared (IR) stimulation at 50 °C (IR 50 ) and 180 °C (pIRIR 180 ); these cobbles represent four...
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2021
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Online Access: | https://orbit.dtu.dk/en/publications/c37d8850-fce1-49c6-a736-a16cc0b88817 https://doi.org/10.1111/bor.12507 |
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ftdtupubl:oai:pure.atira.dk:publications/c37d8850-fce1-49c6-a736-a16cc0b88817 2024-06-23T07:53:17+00:00 Optical dating of cobble surfaces determines the chronology of Holocene beach ridges in Greenland Souza, Priscila E. Sohbati, Reza Murray, Andrew S. Clemmensen, Lars B. Kroon, Aart Nielsen, Lars 2021 https://orbit.dtu.dk/en/publications/c37d8850-fce1-49c6-a736-a16cc0b88817 https://doi.org/10.1111/bor.12507 eng eng https://orbit.dtu.dk/en/publications/c37d8850-fce1-49c6-a736-a16cc0b88817 info:eu-repo/semantics/closedAccess Souza , P E , Sohbati , R , Murray , A S , Clemmensen , L B , Kroon , A & Nielsen , L 2021 , ' Optical dating of cobble surfaces determines the chronology of Holocene beach ridges in Greenland ' , Boreas , vol. 50 , no. 2 , pp. 606-618 . https://doi.org/10.1111/bor.12507 article 2021 ftdtupubl https://doi.org/10.1111/bor.12507 2024-06-11T15:05:08Z We constrain the age of a cobble beach ridge system in Greenland using Optically Stimulated Luminescence (OSL) dating of buried cobble surfaces. Luminescence signals from six cobbles are measured using infrared (IR) stimulation at 50 °C (IR 50 ) and 180 °C (pIRIR 180 ); these cobbles represent four progressively younger beach ridges lying between ~35 and ~6 m above present sea level. Luminescence–depth profiles show that the IR 50 signals in all the samples and pIRIR 180 signals in four out of six samples are well bleached to depths >1.2 mm into the cobble surfaces. Equivalent doses in well-bleached cobble surface slices (i.e. <1.2 mm) are measured and divided by the effective environmental dose rate to the cobble surfaces in order to derive burial ages. Both IR signals are corrected for anomalous fading using the sample-specific ratio of the field to the laboratory saturation levels. Our results are consistent with a depositional model predicting that the investigated portion of the beach ridge system built out continuously during relative sea level fall between ~5.3 and ~1.9 ka ago. The optical ages suggest that the rate of construction varied considerably, with the highest rates ~3.4 ka ago. Additionally, the lowest-elevation beach ridge investigated here provides the first evidence for a higher-than-present relative sea level, between 1.5 and 2 ka ago, in the Disko coastal region. Article in Journal/Newspaper Greenland Technical University of Denmark: DTU Orbit Greenland Boreas 50 2 606 618 |
institution |
Open Polar |
collection |
Technical University of Denmark: DTU Orbit |
op_collection_id |
ftdtupubl |
language |
English |
description |
We constrain the age of a cobble beach ridge system in Greenland using Optically Stimulated Luminescence (OSL) dating of buried cobble surfaces. Luminescence signals from six cobbles are measured using infrared (IR) stimulation at 50 °C (IR 50 ) and 180 °C (pIRIR 180 ); these cobbles represent four progressively younger beach ridges lying between ~35 and ~6 m above present sea level. Luminescence–depth profiles show that the IR 50 signals in all the samples and pIRIR 180 signals in four out of six samples are well bleached to depths >1.2 mm into the cobble surfaces. Equivalent doses in well-bleached cobble surface slices (i.e. <1.2 mm) are measured and divided by the effective environmental dose rate to the cobble surfaces in order to derive burial ages. Both IR signals are corrected for anomalous fading using the sample-specific ratio of the field to the laboratory saturation levels. Our results are consistent with a depositional model predicting that the investigated portion of the beach ridge system built out continuously during relative sea level fall between ~5.3 and ~1.9 ka ago. The optical ages suggest that the rate of construction varied considerably, with the highest rates ~3.4 ka ago. Additionally, the lowest-elevation beach ridge investigated here provides the first evidence for a higher-than-present relative sea level, between 1.5 and 2 ka ago, in the Disko coastal region. |
format |
Article in Journal/Newspaper |
author |
Souza, Priscila E. Sohbati, Reza Murray, Andrew S. Clemmensen, Lars B. Kroon, Aart Nielsen, Lars |
spellingShingle |
Souza, Priscila E. Sohbati, Reza Murray, Andrew S. Clemmensen, Lars B. Kroon, Aart Nielsen, Lars Optical dating of cobble surfaces determines the chronology of Holocene beach ridges in Greenland |
author_facet |
Souza, Priscila E. Sohbati, Reza Murray, Andrew S. Clemmensen, Lars B. Kroon, Aart Nielsen, Lars |
author_sort |
Souza, Priscila E. |
title |
Optical dating of cobble surfaces determines the chronology of Holocene beach ridges in Greenland |
title_short |
Optical dating of cobble surfaces determines the chronology of Holocene beach ridges in Greenland |
title_full |
Optical dating of cobble surfaces determines the chronology of Holocene beach ridges in Greenland |
title_fullStr |
Optical dating of cobble surfaces determines the chronology of Holocene beach ridges in Greenland |
title_full_unstemmed |
Optical dating of cobble surfaces determines the chronology of Holocene beach ridges in Greenland |
title_sort |
optical dating of cobble surfaces determines the chronology of holocene beach ridges in greenland |
publishDate |
2021 |
url |
https://orbit.dtu.dk/en/publications/c37d8850-fce1-49c6-a736-a16cc0b88817 https://doi.org/10.1111/bor.12507 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland |
genre_facet |
Greenland |
op_source |
Souza , P E , Sohbati , R , Murray , A S , Clemmensen , L B , Kroon , A & Nielsen , L 2021 , ' Optical dating of cobble surfaces determines the chronology of Holocene beach ridges in Greenland ' , Boreas , vol. 50 , no. 2 , pp. 606-618 . https://doi.org/10.1111/bor.12507 |
op_relation |
https://orbit.dtu.dk/en/publications/c37d8850-fce1-49c6-a736-a16cc0b88817 |
op_rights |
info:eu-repo/semantics/closedAccess |
op_doi |
https://doi.org/10.1111/bor.12507 |
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Boreas |
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50 |
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container_start_page |
606 |
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