Quantifying sediment discharge from the Bolivian Andes into the Beni foreland basin from cosmogenic 10Be-derived denudation rates
Abstract: Enormous volumes of sediment are produced in the Central Andes and are then delivered into the foreland basins of Amazon basin tributaries. While cosmogenic nuclides in sediment are a suitable tool to measure the denudation rates of sediment-producing areas, the requirement of steady state...
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| Format: | Article |
| Language: | English |
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Sociedade Brasileira de Geologia
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| Series: | Brazilian Journal of Geology |
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| Online Access: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S2317-48892011000400629&lng=en&tlng=en |
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| author | Hella Wittmann Friedhelm von Blanckenburg Jean-Loup Guyot Laurence Maurice Peter Kubik |
| author_facet | Hella Wittmann Friedhelm von Blanckenburg Jean-Loup Guyot Laurence Maurice Peter Kubik |
| author_sort | Hella Wittmann |
| collection | DOAJ |
| description | Abstract: Enormous volumes of sediment are produced in the Central Andes and are then delivered into the foreland basins of Amazon basin tributaries. While cosmogenic nuclides in sediment are a suitable tool to measure the denudation rates of sediment-producing areas, the requirement of steady state between nuclide production and nuclide removal by denudation appears to make this method less obvious in depositional foreland basins, where sediment storage may alter 10Be-based erosion signals from the sediment-providing areas. A published cosmogenic nuclide-based modeling approach however predicts that source-area cosmogenic nuclide concentrations are not modified by temporary sediment storage. We tested this approach in the large Beni foreland basin by measuring cosmogenic 10Be nuclide concentrations in detrital sediment along a 600 km long floodplain reach. The outcome of our study is that the 10Be-based denudation rate signal of the Bolivian Andes is preserved in the Beni floodplain even though this basin stores the sediment for thousands of years. For the floodplain part of the Beni basin, the cosmogenic nuclide-derived denudation rate is 0.45 ± 0.07 mm/yr, and the respective Andean source area erodes at a very similar rate of 0.37 ± 0.06 mm/yr. We thus suggest that any sample collected along a river traversing a floodplain will yield the denudation rate of the source area. This finding opens the unique possibility of constraining paleo-sediment budgets for these large basins using cosmogenic nuclides as the denudation rate signal of the sediment-producing area is preserved in sedimentary archives. |
| first_indexed | 2024-12-23T03:29:23Z |
| format | Article |
| id | doaj.art-0406103bc5834169b7c1f39c8dfc4285 |
| institution | Directory Open Access Journal |
| issn | 2317-4692 |
| language | English |
| last_indexed | 2024-12-23T03:29:23Z |
| publisher | Sociedade Brasileira de Geologia |
| record_format | Article |
| series | Brazilian Journal of Geology |
| spelling | doaj.art-0406103bc5834169b7c1f39c8dfc42852022-12-21T18:01:44ZengSociedade Brasileira de GeologiaBrazilian Journal of Geology2317-469241462964110.25249/0375-7536.2011414629641S2317-48892011000400629Quantifying sediment discharge from the Bolivian Andes into the Beni foreland basin from cosmogenic 10Be-derived denudation ratesHella WittmannFriedhelm von BlanckenburgJean-Loup GuyotLaurence MauricePeter KubikAbstract: Enormous volumes of sediment are produced in the Central Andes and are then delivered into the foreland basins of Amazon basin tributaries. While cosmogenic nuclides in sediment are a suitable tool to measure the denudation rates of sediment-producing areas, the requirement of steady state between nuclide production and nuclide removal by denudation appears to make this method less obvious in depositional foreland basins, where sediment storage may alter 10Be-based erosion signals from the sediment-providing areas. A published cosmogenic nuclide-based modeling approach however predicts that source-area cosmogenic nuclide concentrations are not modified by temporary sediment storage. We tested this approach in the large Beni foreland basin by measuring cosmogenic 10Be nuclide concentrations in detrital sediment along a 600 km long floodplain reach. The outcome of our study is that the 10Be-based denudation rate signal of the Bolivian Andes is preserved in the Beni floodplain even though this basin stores the sediment for thousands of years. For the floodplain part of the Beni basin, the cosmogenic nuclide-derived denudation rate is 0.45 ± 0.07 mm/yr, and the respective Andean source area erodes at a very similar rate of 0.37 ± 0.06 mm/yr. We thus suggest that any sample collected along a river traversing a floodplain will yield the denudation rate of the source area. This finding opens the unique possibility of constraining paleo-sediment budgets for these large basins using cosmogenic nuclides as the denudation rate signal of the sediment-producing area is preserved in sedimentary archives.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S2317-48892011000400629&lng=en&tlng=enDenudaçãoErosãoFornecimento de sedimentoCosmonuclídeos10Be cosmogênicoAndes bolivianosRio Beni, Rio Madeira |
| spellingShingle | Hella Wittmann Friedhelm von Blanckenburg Jean-Loup Guyot Laurence Maurice Peter Kubik Quantifying sediment discharge from the Bolivian Andes into the Beni foreland basin from cosmogenic 10Be-derived denudation rates Brazilian Journal of Geology Denudação Erosão Fornecimento de sedimento Cosmonuclídeos 10Be cosmogênico Andes bolivianos Rio Beni, Rio Madeira |
| title | Quantifying sediment discharge from the Bolivian Andes into the Beni foreland basin from cosmogenic 10Be-derived denudation rates |
| title_full | Quantifying sediment discharge from the Bolivian Andes into the Beni foreland basin from cosmogenic 10Be-derived denudation rates |
| title_fullStr | Quantifying sediment discharge from the Bolivian Andes into the Beni foreland basin from cosmogenic 10Be-derived denudation rates |
| title_full_unstemmed | Quantifying sediment discharge from the Bolivian Andes into the Beni foreland basin from cosmogenic 10Be-derived denudation rates |
| title_short | Quantifying sediment discharge from the Bolivian Andes into the Beni foreland basin from cosmogenic 10Be-derived denudation rates |
| title_sort | quantifying sediment discharge from the bolivian andes into the beni foreland basin from cosmogenic 10be derived denudation rates |
| topic | Denudação Erosão Fornecimento de sedimento Cosmonuclídeos 10Be cosmogênico Andes bolivianos Rio Beni, Rio Madeira |
| url | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S2317-48892011000400629&lng=en&tlng=en |
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