<abstract xmlns="http://www.w3.org/1999/xhtml">Knowledge of the age of fluvial deposits is an important aspect in the understanding of river dynamics, which is pre-requisite for sustainable river management and restoration back to more natural conditions and processes. Presented here is a case study on using feldspar Infrared Stimulated Luminescence (IRSL) to date low-energy fluvial sediments that formed after correction of the Upper Rhine River in the first half of the 19th century. A rigorous testing programme is carried out to characterise the IRSL properties of the samples, including thermal transfer, dose recovery and fading. All samples reveal complex distributions of equivalent dose, implying the presence of differential bleach-ing in the samples. It is shown that multi-grain aliquots overestimate the known-age by up-to 200 years, i.e. apparent IRSL ages are twice as old as the true age of the sediment. The use of single grains results in ages that are in excellent agreement with the expected age, therefore the age overestimation in multi-grain aliquot measurements is likely explained by signal averaging effects. While the application of single grains appears mandatory for dating young low-energy fluvial deposits, the small absolute offset associated with the multi-grain approach might be acceptable when dating sediments of such type that are older than a few 1000 years.</abstract>

Knowledge of the age of fluvial deposits is an important aspect in the understanding of river dynamics, which is pre-requisite for sustainable river management and restoration back to more natural conditions and processes. Presented here is a case study on using feldspar Infrared Stimulated Luminescence (IRSL) to date low-energy fluvial sediments that formed after correction of the Upper Rhine River in the first half of the 19th century. A rigorous testing programme is carried out to characterise the IRSL properties of the samples, including thermal transfer, dose recovery and fading. All samples reveal complex distributions of equivalent dose, implying the presence of differential bleach-ing in the samples. It is shown that multi-grain aliquots overestimate the known-age by up-to 200 years, i.e. apparent IRSL ages are twice as old as the true age of the sediment. The use of single grains results in ages that are in excellent agreement with the expected age, therefore the age overestimation in multi-grain aliquot measurements is likely explained by signal averaging effects. While the application of single grains appears mandatory for dating young low-energy fluvial deposits, the small absolute offset associated with the multi-grain approach might be acceptable when dating sediments of such type that are older than a few 1000 years.

Infrared stimulated luminescence dating of 19th century fluvial deposits from the upper Rhine River

Institute of Earth and Environmental Sciences, University of Freiburg, Albertstraβe 23b, 79104 Freiburg,

University of Strasbourg, UMR LIVE 7362 - CNRS-UNISTRA-ENGEES, 67083 Strasbourg,

Institute of Geography, University of Bern, Hallerstrasse 12, 3012 Bern,

Geochronometria

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Infrared stimulated luminescence dating of 19 century fluvial deposits from the upper Rhine River

Knowledge of the age of fluvial deposits is an important aspect in the understanding of river dynamics, which is pre-requisite for sustainable river management...

Infrared stimulated luminescence dating of 19^th century fluvial deposits from the upper Rhine River

Publié en ligne: 30 déc. 2016

Pages: 131 - 142

Reçu: 19 mai 2016

Accepté: 15 nov. 2016

DOI: https://doi.org/10.1515/geochr-2015-0045

Mots clés
luminescence (IRSL) dating, fluvial sediments, historic, feldspar, Rhine

© 2016 F. Preusser.

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Infrared stimulated luminescence dating of 19th century fluvial deposits from the upper Rhine River

Publié en ligne: 30 déc. 2016

Pages: 131 - 142

Reçu: 19 mai 2016

Accepté: 15 nov. 2016

DOI: https://doi.org/10.1515/geochr-2015-0045

Mots clésluminescence (IRSL) dating, fluvial sediments, historic, feldspar, Rhine

© 2016 F. Preusser.

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Infrared stimulated luminescence dating of 19^th century fluvial deposits from the upper Rhine River

Mots clés
luminescence (IRSL) dating, fluvial sediments, historic, feldspar, Rhine