Tracking the <sup>10</sup>Be–<sup>26</sup>Al source-area signal in sediment-routing systems of arid central Australia
Sediment-routing systems continuously transfer information and mass from eroding source areas to depositional sinks. Understanding how these systems alter environmental signals is critical when it comes to inferring source-area properties from the sedimentary record. We measure cosmogenic <su...
| Main Authors: | , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2018-05-01
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| Series: | Earth Surface Dynamics |
| Online Access: | https://www.earth-surf-dynam.net/6/329/2018/esurf-6-329-2018.pdf |
| _version_ | 1828846364003401728 |
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| author | M. Struck J. D. Jansen T. Fujioka A. T. Codilean D. Fink R.-H. Fülöp R.-H. Fülöp K. M. Wilcken D. M. Price S. Kotevski L. K. Fifield J. Chappell |
| author_facet | M. Struck J. D. Jansen T. Fujioka A. T. Codilean D. Fink R.-H. Fülöp R.-H. Fülöp K. M. Wilcken D. M. Price S. Kotevski L. K. Fifield J. Chappell |
| author_sort | M. Struck |
| collection | DOAJ |
| description | Sediment-routing systems continuously transfer information and mass from
eroding source areas to depositional sinks. Understanding how these systems
alter environmental signals is critical when it comes to inferring
source-area properties from the sedimentary record. We measure cosmogenic
<sup>10</sup>Be and <sup>26</sup>Al along three large sediment-routing systems
( ∼ 100 000 km<sup>2</sup>) in central Australia with the aim of
tracking downstream variations in <sup>10</sup>Be–<sup>26</sup>Al inventories and
identifying the factors responsible for these variations. By comparing 56 new
cosmogenic <sup>10</sup>Be and <sup>26</sup>Al measurements in stream sediments with
matching data (<i>n</i> = 55) from source areas, we show that <sup>10</sup>Be–<sup>26</sup>Al
inventories in hillslope bedrock and soils set the benchmark for relative
downstream modifications. Lithology is the primary determinant of
erosion-rate variations in source areas and despite sediment mixing over
hundreds of kilometres downstream, a distinct lithological signal is retained.
Post-orogenic ranges yield catchment erosion rates of ∼ 6–11 m Myr<sup>−1</sup> and silcrete-dominant areas erode as slow as
∼ 0.2 m Myr<sup>−1</sup>. <sup>10</sup>Be–<sup>26</sup>Al inventories in
stream sediments indicate that cumulative-burial terms increase downstream to
mostly ∼ 400–800 kyr and up to
∼ 1.1 Myr. The magnitude of the
burial signal correlates with increasing sediment cover downstream and
reflects assimilation from storages with long exposure histories, such as
alluvial fans, desert pavements, alluvial plains, and aeolian dunes. We
propose that the tendency for large alluvial rivers to mask their
<sup>10</sup>Be–<sup>26</sup>Al source-area signal differs according to geomorphic
setting. Signal preservation is favoured by (i) high sediment supply rates,
(ii) high mean runoff, and (iii) a thick sedimentary basin pile. Conversely,
signal masking prevails in landscapes of (i) low sediment supply and (ii) juxtaposition of sediment storages with notably different exposure histories. |
| first_indexed | 2024-12-12T21:47:34Z |
| format | Article |
| id | doaj.art-4bb628e1a46744a9a804bffaeedf5e65 |
| institution | Directory Open Access Journal |
| issn | 2196-6311 2196-632X |
| language | English |
| last_indexed | 2024-12-12T21:47:34Z |
| publishDate | 2018-05-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Earth Surface Dynamics |
| spelling | doaj.art-4bb628e1a46744a9a804bffaeedf5e652022-12-22T00:10:53ZengCopernicus PublicationsEarth Surface Dynamics2196-63112196-632X2018-05-01632934910.5194/esurf-6-329-2018Tracking the <sup>10</sup>Be–<sup>26</sup>Al source-area signal in sediment-routing systems of arid central AustraliaM. Struck0J. D. Jansen1T. Fujioka2A. T. Codilean3D. Fink4R.-H. Fülöp5R.-H. Fülöp6K. M. Wilcken7D. M. Price8S. Kotevski9L. K. Fifield10J. Chappell11School of Earth and Environmental Sciences, University of Wollongong, Wollongong 2522, AustraliaDepartment of Geoscience, Aarhus University, 8000 Aarhus C, DenmarkAustralian Nuclear Science and Technology Organisation, Lucas Heights 2234, AustraliaSchool of Earth and Environmental Sciences, University of Wollongong, Wollongong 2522, AustraliaAustralian Nuclear Science and Technology Organisation, Lucas Heights 2234, AustraliaSchool of Earth and Environmental Sciences, University of Wollongong, Wollongong 2522, AustraliaAustralian Nuclear Science and Technology Organisation, Lucas Heights 2234, AustraliaAustralian Nuclear Science and Technology Organisation, Lucas Heights 2234, AustraliaSchool of Earth and Environmental Sciences, University of Wollongong, Wollongong 2522, AustraliaAustralian Nuclear Science and Technology Organisation, Lucas Heights 2234, AustraliaResearch School of Earth Sciences, Australian National University, Canberra 0200, AustraliaResearch School of Earth Sciences, Australian National University, Canberra 0200, AustraliaSediment-routing systems continuously transfer information and mass from eroding source areas to depositional sinks. Understanding how these systems alter environmental signals is critical when it comes to inferring source-area properties from the sedimentary record. We measure cosmogenic <sup>10</sup>Be and <sup>26</sup>Al along three large sediment-routing systems ( ∼ 100 000 km<sup>2</sup>) in central Australia with the aim of tracking downstream variations in <sup>10</sup>Be–<sup>26</sup>Al inventories and identifying the factors responsible for these variations. By comparing 56 new cosmogenic <sup>10</sup>Be and <sup>26</sup>Al measurements in stream sediments with matching data (<i>n</i> = 55) from source areas, we show that <sup>10</sup>Be–<sup>26</sup>Al inventories in hillslope bedrock and soils set the benchmark for relative downstream modifications. Lithology is the primary determinant of erosion-rate variations in source areas and despite sediment mixing over hundreds of kilometres downstream, a distinct lithological signal is retained. Post-orogenic ranges yield catchment erosion rates of ∼ 6–11 m Myr<sup>−1</sup> and silcrete-dominant areas erode as slow as ∼ 0.2 m Myr<sup>−1</sup>. <sup>10</sup>Be–<sup>26</sup>Al inventories in stream sediments indicate that cumulative-burial terms increase downstream to mostly ∼ 400–800 kyr and up to ∼ 1.1 Myr. The magnitude of the burial signal correlates with increasing sediment cover downstream and reflects assimilation from storages with long exposure histories, such as alluvial fans, desert pavements, alluvial plains, and aeolian dunes. We propose that the tendency for large alluvial rivers to mask their <sup>10</sup>Be–<sup>26</sup>Al source-area signal differs according to geomorphic setting. Signal preservation is favoured by (i) high sediment supply rates, (ii) high mean runoff, and (iii) a thick sedimentary basin pile. Conversely, signal masking prevails in landscapes of (i) low sediment supply and (ii) juxtaposition of sediment storages with notably different exposure histories.https://www.earth-surf-dynam.net/6/329/2018/esurf-6-329-2018.pdf |
| spellingShingle | M. Struck J. D. Jansen T. Fujioka A. T. Codilean D. Fink R.-H. Fülöp R.-H. Fülöp K. M. Wilcken D. M. Price S. Kotevski L. K. Fifield J. Chappell Tracking the <sup>10</sup>Be–<sup>26</sup>Al source-area signal in sediment-routing systems of arid central Australia Earth Surface Dynamics |
| title | Tracking the <sup>10</sup>Be–<sup>26</sup>Al source-area signal in sediment-routing systems of arid central Australia |
| title_full | Tracking the <sup>10</sup>Be–<sup>26</sup>Al source-area signal in sediment-routing systems of arid central Australia |
| title_fullStr | Tracking the <sup>10</sup>Be–<sup>26</sup>Al source-area signal in sediment-routing systems of arid central Australia |
| title_full_unstemmed | Tracking the <sup>10</sup>Be–<sup>26</sup>Al source-area signal in sediment-routing systems of arid central Australia |
| title_short | Tracking the <sup>10</sup>Be–<sup>26</sup>Al source-area signal in sediment-routing systems of arid central Australia |
| title_sort | tracking the sup 10 sup be sup 26 sup al source area signal in sediment routing systems of arid central australia |
| url | https://www.earth-surf-dynam.net/6/329/2018/esurf-6-329-2018.pdf |
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