<abstract xmlns="http://www.w3.org/1999/xhtml">

<p>Optically stimulated luminescence (OSL) dating of fine-grained (4–11 μm) fluvial sediments is rarely attempted but is crucial for constraining the evolution of mud-dominated floodplains. This study investigated the applicability of OSL dating to fine-grained deposits in the Mekong River, Cambodia based on a very young (&lt;600 yr) point-bar to riverbank succession and modern flood deposits. In succession, fine-grained quartz OSL provided the youngest ages, whereas age estimates by multi-grain sand-sized quartz OSL, and feldspar and polymineral infrared-stimulated luminescence are >200 years older than the fine-grained quartz OSL age estimates. Ages of fine-grained quartz OSL are concordant with the minimum ages obtained from the single-grain quartz OSL. These results are supported by the generally small residual doses (&lt;0.1 Gy) measured in modern fine-grained flood-plain deposits. This indicates that fine-grained sediments in the Mekong River (Cambodia) are sufficiently bleached at deposition and can yield reliable quartz OSL ages for establishing the chronology of the floodplain. The sufficient bleaching of fine-grained quartz partly results from the long transport distance and may also occur in other large river systems.</p>
</abstract>

Optically stimulated luminescence (OSL) dating of fine-grained (4–11 μm) fluvial sediments is rarely attempted but is crucial for constraining the evolution of mud-dominated floodplains. This study investigated the applicability of OSL dating to fine-grained deposits in the Mekong River, Cambodia based on a very young (<600 yr) point-bar to riverbank succession and modern flood deposits. In succession, fine-grained quartz OSL provided the youngest ages, whereas age estimates by multi-grain sand-sized quartz OSL, and feldspar and polymineral infrared-stimulated luminescence are >200 years older than the fine-grained quartz OSL age estimates. Ages of fine-grained quartz OSL are concordant with the minimum ages obtained from the single-grain quartz OSL. These results are supported by the generally small residual doses (<0.1 Gy) measured in modern fine-grained flood-plain deposits. This indicates that fine-grained sediments in the Mekong River (Cambodia) are sufficiently bleached at deposition and can yield reliable quartz OSL ages for establishing the chronology of the floodplain. The sufficient bleaching of fine-grained quartz partly results from the long transport distance and may also occur in other large river systems.

Applicability of OSL Dating to Fine-Grained Fluvial Deposits in the Mekong River Floodplain, Cambodia

Geochronometria

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

Optically stimulated luminescence (OSL) dating of fine-grained (4–11 μm) fluvial sediments is rarely attempted but is crucial for constraining the evolution of mud-dominated floodplains. This study investigated the applicability of OSL dating to fine-grained deposits in the Mekong River, Cambodia based on a very young (200 years older than the fine-grained quartz OSL age estimates. Ages of fine-grained quartz OSL are concordant with the minimum ages obtained from the single-grain quartz OSL. These results are supported by the generally small residual doses (<0.1 Gy) measured in modern fine-grained flood-plain deposits. This indicates that fine-grained sediments in the Mekong River (Cambodia) are sufficiently bleached at deposition and can yield reliable quartz OSL ages for establishing the chronology of the floodplain. The sufficient bleaching of fine-grained quartz partly results from the long transport distance and may also occur in other large river systems.

Optically stimulated luminescence (OSL) dating of fine-grained (4–11 μm) fluvial sediments is rarely attempted but is crucial for constraining the evolution of...

Applicability of OSL Dating to Fine-Grained Fluvial Deposits in the Mekong River Floodplain, Cambodia

Published Online: Dec 31, 2021

Page range: 351 - 363

Received: Jan 15, 2019

Accepted: Aug 22, 2019

DOI: https://doi.org/10.2478/geochr-2020-0006

Keywords
OSL dating, incomplete bleaching, fluvial deposits, Mekong River

© 2019 Yuji Ishii et al., published by Sciendo

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

Applicability of OSL Dating to Fine-Grained Fluvial Deposits in the Mekong River Floodplain, Cambodia

Published Online: Dec 31, 2021

Page range: 351 - 363

Received: Jan 15, 2019

Accepted: Aug 22, 2019

DOI: https://doi.org/10.2478/geochr-2020-0006

KeywordsOSL dating, incomplete bleaching, fluvial deposits, Mekong River

© 2019 Yuji Ishii et al., published by Sciendo

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

Keywords
OSL dating, incomplete bleaching, fluvial deposits, Mekong River