Global analysis of in situ cosmogenic <sup>26</sup>Al and <sup>10</sup>Be and inferred erosion rate ratios in modern fluvial sediments indicates widespread sediment storage and burial during transport

<p>Since the 1990s, analysis of cosmogenic nuclides, primarily <span class="inline-formula"><sup>10</sup>Be</span>, in quartz-bearing river sand has allowed the quantitative determination of landscape mass loss rates (hereafter, erosion rates) at a basin scale...

Full description

Saved in:
Bibliographic Details
Main Authors: C. T. Halsted, P. R. Bierman, A. T. Codilean, L. B. Corbett, M. W. Caffee
Format: Article
Language:English
Published: Copernicus Publications 2025-07-01
Series:Geochronology
Online Access:https://gchron.copernicus.org/articles/7/213/2025/gchron-7-213-2025.pdf
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1839633042842320896
author C. T. Halsted
P. R. Bierman
A. T. Codilean
L. B. Corbett
M. W. Caffee
author_facet C. T. Halsted
P. R. Bierman
A. T. Codilean
L. B. Corbett
M. W. Caffee
author_sort C. T. Halsted
collection DOAJ
description <p>Since the 1990s, analysis of cosmogenic nuclides, primarily <span class="inline-formula"><sup>10</sup>Be</span>, in quartz-bearing river sand has allowed the quantitative determination of landscape mass loss rates (hereafter, erosion rates) at a basin scale. Paired measurements of in situ cosmogenic <span class="inline-formula"><sup>26</sup>Al</span> and <span class="inline-formula"><sup>10</sup>Be</span> in sediment are less common but offer insight into the integrated exposure and burial history of sediment moving down slopes and through drainage basins. Prolonged burial (<span class="inline-formula">&gt;10<sup>5</sup></span> years), a violation of assumptions underlying erosion rate calculations, is indicated by higher <span class="inline-formula"><sup>26</sup>Al</span>-based than <span class="inline-formula"><sup>10</sup>Be</span>-based erosion rates due to preferential loss of shorter-lived <span class="inline-formula"><sup>26</sup>Al</span> by decay when quartz is at least in part shielded from cosmic rays.</p> <p>Here, we use a global compilation of <span class="inline-formula"><sup>26</sup>Al</span> and <span class="inline-formula"><sup>10</sup>Be</span> data generated from quartz-bearing fluvial sediment samples (<span class="inline-formula"><i>n</i>=766</span>, including 117 new measurements) to calculate the discordance between erosion rates derived from each nuclide. We find that over 30 % of samples (<span class="inline-formula"><i>n</i>=234</span>) exhibit discordance (<span class="inline-formula">&gt;2<i>σ</i></span> analytical uncertainty) between erosion rates derived from <span class="inline-formula"><sup>10</sup>Be</span> and <span class="inline-formula"><sup>26</sup>Al</span>, indicating sediment histories that include extended burial during residence on hillslopes and/or in the fluvial system after or during initial near-surface exposure. Physical basin parameters, such as basin area, slope, and tectonic activity, exhibit significant correlation with erosion rate discordance, whereas climatic parameters have weak correlation, allowing us to infer the likelihood of sediment burial during transport in different geomorphic settings.</p> <p>Paired <span class="inline-formula"><sup>26</sup>Al</span> and <span class="inline-formula"><sup>10</sup>Be</span> analyses in detrital fluvial samples provide a window into watershed processes, elucidating landscape behavior at different spatial scales and allowing a deeper understanding of both sediment routing systems and whether methodological assumptions are violated. Although previous studies have found <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M19" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><msup><mi/><mn mathvariant="normal">26</mn></msup><mi mathvariant="normal">Al</mi><msup><mo>/</mo><mn mathvariant="normal">10</mn></msup><mi mathvariant="normal">Be</mi></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="50pt" height="15pt" class="svg-formula" dspmath="mathimg" md5hash="9ebd76438a11b1dc3bad7ce831cf1b46"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="gchron-7-213-2025-ie00001.svg" width="50pt" height="15pt" src="gchron-7-213-2025-ie00001.png"/></svg:svg></span></span> erosion rate discordance to be common in the world's largest drainage basins, our analysis suggests that such discordance also occurs regularly in basins as small as 1000 <span class="inline-formula">km<sup>2</sup></span>, indicating that sediment storage mechanisms are more complex than suggested by simple floodplain area scaling laws. Moderately sized basins (1000–10 000 <span class="inline-formula">km<sup>2</sup></span>) with low average slopes in tectonically quiescent terrains appear conducive to extended sediment storage; thus, erosion rates from such basins are lower limits due to nuclide decay during storage. We find that sediment sourced from smaller, steeper basins in tectonically active regions is more likely to have similar <span class="inline-formula"><sup>10</sup>Be</span> and <span class="inline-formula"><sup>26</sup>Al</span> erosion rates indicative of limited storage and is thus more likely to provide reliable erosion rates.</p>
format Article
id doaj-art-db312c6162df44d7965cd9224d85a55d
institution Matheson Library
issn 2628-3697
2628-3719
language English
publishDate 2025-07-01
publisher Copernicus Publications
record_format Article
series Geochronology
spelling doaj-art-db312c6162df44d7965cd9224d85a55d2025-07-11T05:38:13ZengCopernicus PublicationsGeochronology2628-36972628-37192025-07-01721322810.5194/gchron-7-213-2025Global analysis of in situ cosmogenic <sup>26</sup>Al and <sup>10</sup>Be and inferred erosion rate ratios in modern fluvial sediments indicates widespread sediment storage and burial during transportC. T. Halsted0P. R. Bierman1A. T. Codilean2L. B. Corbett3M. W. Caffee4Department of Geosciences, Williams College, Williamstown, MA 01267, USARubenstein School of Environment and Natural Resources, University of Vermont, Burlington, VT 05405, USASchool of Science and Australian Research Council Centre of Excellence for Australian Biodiversity and Heritage (CABAH), University of Wollongong, Wollongong NSW 2522, AustraliaRubenstein School of Environment and Natural Resources, University of Vermont, Burlington, VT 05405, USADepartment of Physics and Astronomy, Purdue University, West Lafayette, IN 47907, USA<p>Since the 1990s, analysis of cosmogenic nuclides, primarily <span class="inline-formula"><sup>10</sup>Be</span>, in quartz-bearing river sand has allowed the quantitative determination of landscape mass loss rates (hereafter, erosion rates) at a basin scale. Paired measurements of in situ cosmogenic <span class="inline-formula"><sup>26</sup>Al</span> and <span class="inline-formula"><sup>10</sup>Be</span> in sediment are less common but offer insight into the integrated exposure and burial history of sediment moving down slopes and through drainage basins. Prolonged burial (<span class="inline-formula">&gt;10<sup>5</sup></span> years), a violation of assumptions underlying erosion rate calculations, is indicated by higher <span class="inline-formula"><sup>26</sup>Al</span>-based than <span class="inline-formula"><sup>10</sup>Be</span>-based erosion rates due to preferential loss of shorter-lived <span class="inline-formula"><sup>26</sup>Al</span> by decay when quartz is at least in part shielded from cosmic rays.</p> <p>Here, we use a global compilation of <span class="inline-formula"><sup>26</sup>Al</span> and <span class="inline-formula"><sup>10</sup>Be</span> data generated from quartz-bearing fluvial sediment samples (<span class="inline-formula"><i>n</i>=766</span>, including 117 new measurements) to calculate the discordance between erosion rates derived from each nuclide. We find that over 30 % of samples (<span class="inline-formula"><i>n</i>=234</span>) exhibit discordance (<span class="inline-formula">&gt;2<i>σ</i></span> analytical uncertainty) between erosion rates derived from <span class="inline-formula"><sup>10</sup>Be</span> and <span class="inline-formula"><sup>26</sup>Al</span>, indicating sediment histories that include extended burial during residence on hillslopes and/or in the fluvial system after or during initial near-surface exposure. Physical basin parameters, such as basin area, slope, and tectonic activity, exhibit significant correlation with erosion rate discordance, whereas climatic parameters have weak correlation, allowing us to infer the likelihood of sediment burial during transport in different geomorphic settings.</p> <p>Paired <span class="inline-formula"><sup>26</sup>Al</span> and <span class="inline-formula"><sup>10</sup>Be</span> analyses in detrital fluvial samples provide a window into watershed processes, elucidating landscape behavior at different spatial scales and allowing a deeper understanding of both sediment routing systems and whether methodological assumptions are violated. Although previous studies have found <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M19" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><msup><mi/><mn mathvariant="normal">26</mn></msup><mi mathvariant="normal">Al</mi><msup><mo>/</mo><mn mathvariant="normal">10</mn></msup><mi mathvariant="normal">Be</mi></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="50pt" height="15pt" class="svg-formula" dspmath="mathimg" md5hash="9ebd76438a11b1dc3bad7ce831cf1b46"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="gchron-7-213-2025-ie00001.svg" width="50pt" height="15pt" src="gchron-7-213-2025-ie00001.png"/></svg:svg></span></span> erosion rate discordance to be common in the world's largest drainage basins, our analysis suggests that such discordance also occurs regularly in basins as small as 1000 <span class="inline-formula">km<sup>2</sup></span>, indicating that sediment storage mechanisms are more complex than suggested by simple floodplain area scaling laws. Moderately sized basins (1000–10 000 <span class="inline-formula">km<sup>2</sup></span>) with low average slopes in tectonically quiescent terrains appear conducive to extended sediment storage; thus, erosion rates from such basins are lower limits due to nuclide decay during storage. We find that sediment sourced from smaller, steeper basins in tectonically active regions is more likely to have similar <span class="inline-formula"><sup>10</sup>Be</span> and <span class="inline-formula"><sup>26</sup>Al</span> erosion rates indicative of limited storage and is thus more likely to provide reliable erosion rates.</p>https://gchron.copernicus.org/articles/7/213/2025/gchron-7-213-2025.pdf
spellingShingle C. T. Halsted
P. R. Bierman
A. T. Codilean
L. B. Corbett
M. W. Caffee
Global analysis of in situ cosmogenic <sup>26</sup>Al and <sup>10</sup>Be and inferred erosion rate ratios in modern fluvial sediments indicates widespread sediment storage and burial during transport
Geochronology
title Global analysis of in situ cosmogenic <sup>26</sup>Al and <sup>10</sup>Be and inferred erosion rate ratios in modern fluvial sediments indicates widespread sediment storage and burial during transport
title_full Global analysis of in situ cosmogenic <sup>26</sup>Al and <sup>10</sup>Be and inferred erosion rate ratios in modern fluvial sediments indicates widespread sediment storage and burial during transport
title_fullStr Global analysis of in situ cosmogenic <sup>26</sup>Al and <sup>10</sup>Be and inferred erosion rate ratios in modern fluvial sediments indicates widespread sediment storage and burial during transport
title_full_unstemmed Global analysis of in situ cosmogenic <sup>26</sup>Al and <sup>10</sup>Be and inferred erosion rate ratios in modern fluvial sediments indicates widespread sediment storage and burial during transport
title_short Global analysis of in situ cosmogenic <sup>26</sup>Al and <sup>10</sup>Be and inferred erosion rate ratios in modern fluvial sediments indicates widespread sediment storage and burial during transport
title_sort global analysis of in situ cosmogenic sup 26 sup al and sup 10 sup be and inferred erosion rate ratios in modern fluvial sediments indicates widespread sediment storage and burial during transport
url https://gchron.copernicus.org/articles/7/213/2025/gchron-7-213-2025.pdf
work_keys_str_mv AT cthalsted globalanalysisofinsitucosmogenicsup26supalandsup10supbeandinferrederosionrateratiosinmodernfluvialsedimentsindicateswidespreadsedimentstorageandburialduringtransport
AT prbierman globalanalysisofinsitucosmogenicsup26supalandsup10supbeandinferrederosionrateratiosinmodernfluvialsedimentsindicateswidespreadsedimentstorageandburialduringtransport
AT atcodilean globalanalysisofinsitucosmogenicsup26supalandsup10supbeandinferrederosionrateratiosinmodernfluvialsedimentsindicateswidespreadsedimentstorageandburialduringtransport
AT lbcorbett globalanalysisofinsitucosmogenicsup26supalandsup10supbeandinferrederosionrateratiosinmodernfluvialsedimentsindicateswidespreadsedimentstorageandburialduringtransport
AT mwcaffee globalanalysisofinsitucosmogenicsup26supalandsup10supbeandinferrederosionrateratiosinmodernfluvialsedimentsindicateswidespreadsedimentstorageandburialduringtransport