Quantifying sediment transport on desert piedmonts using 10Be and 26Al

Nichols, Kyle K.; Bierman, Paul R.; Hooke, Roger LeB.; Clapp, Erik M.; Caffee, Marc W.

doi:10.1016/s0169-555x(01)00192-1

Cited by 62 publications

(92 citation statements)

References 29 publications

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“…Even where these complexities are present, cosmogenic nuclides mostly record robust basinwide denudation rates when compared to long-term denudation meters measured by fission tracks (Kirchner et al, 2001;Matmon et al, 2003;Wittmann et al, 2007). The question posed here is whether this method can be used to infer basin-wide denudation rates from sediment routed through large depositional settings (Bierman and Steig, 1996;Nichols et al, 2002;Nichols et al, 2005). In such basins, the transport of sediment includes residence in floodplains due to deposition in the floodplain and reincorporation of sediment in the active fluvial system by bank erosion.…”

Section: Introductionmentioning

confidence: 99%

From source to sink: Preserving the cosmogenic 10Be-derived denudation rate signal of the Bolivian Andes in sediment of the Beni and Mamoré foreland basins

Wittmann

Blanckenburg

Guyot³

et al. 2009

Earth and Planetary Science Letters

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The denudation rate signal of the Bolivian Andes as measured by cosmogenic 10 Be in sediment is preserved in the floodplain of adjacent foreland basins even though these basins store the sediment for thousands of years. This conclusion is drawn from comparing published Andean source area denudation rates with new cosmogenic 10 Be data as measured in the floodplains of the large Beni and Mamoré basins. For the entire Beni basin including the sediment producing Andes and the vast flooded plains of the foreland, the cosmogenic nuclide-derived denudation rate is 0.45 ± 0.06 mm/yr, while that of the Mamoré basin is 0.55 ± 0.19 mm/yr. By comparison, the respective Andean source areas erode at averaged rates of 0.37 ± 0.06 mm/yr (upper Beni), and at 0.56 ± 0.09 mm/yr (upper Mamoré). We notice a decrease in variability of denudation rate with increasing spatial scale as small-scale processes are averaged out. Sediment mixing within the floodplain damps scatter of nuclide-derived denudation rates picked up in the source area. On the temporal scale, a remarkable agreement between cosmogenic nuclide-derived rates averaging over a few kiloyears with those from fission track dating averaging over millions of years seems to suggest that cosmogenic nuclide-derived denudation rates capture the long-term erosional characteristics of the mountain belt. The sum of these observations suggests 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 cosmogenic nuclide-derived paleo-sediment budgets for these large basins as the long-term, spatially-averaged denudation rate signal of the sediment-producing area is preserved in sedimentary archives.

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Section: Introductionmentioning

confidence: 99%

From source to sink: Preserving the cosmogenic 10Be-derived denudation rate signal of the Bolivian Andes in sediment of the Beni and Mamoré foreland basins

Wittmann

Blanckenburg

Guyot³

et al. 2009

Earth and Planetary Science Letters

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“…In this study, we will test whether this method can be used to infer basin-wide denudation rates from sediment routed through large depositional settings (Bierman & Steig 1996, Nichols et al 2005, Nichols et al 2002. In such basins, sediment is continuously deposited in the fl oodplain and reincorporated in the active fl uvial system by bank erosion.…”

Section: Quantifying Sediment Discharge From the Bolivian Andes Into mentioning

confidence: 99%

Quantifying sediment discharge from the Bolivian Andes into the Beni foreland basin from cosmogenic 10Be-derived denudation rates

Wittmann

Blanckenburg

Guyot

et al. 2011

RBG

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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 10 Be-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 modifi ed by temporary sediment storage. We tested this approach in the large Beni foreland basin by measuring cosmogenic 10 Be nuclide concentrations in detrital sediment along a 600 km long fl oodplain reach. The outcome of our study is that the 10 Be-based denudation rate signal of the Bolivian Andes is preserved in the Beni fl oodplain even though this basin stores the sediment for thousands of years. For the fl oodplain 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 fl oodplain will yield the denudation rate of the source area. This fi nding 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.Keywords: Denudation, Erosion, Sediment delivery, Cosmogenic nuclides, Cosmogenic 10 Be, Bolivian Andes, Beni River, Madeira River. Resumo Quantifi cação da descarga sedimentar na bacia de Beni (Andes bolivianos) por meio da taxa de denudação obtida por isótopos cosmogênicos de 10Be. O grande volume de sedimento produzido pelas bacias foreland dos Andes Centrais é carregado pelos tributários da bacia do rio Amazonas. Embora os cosmonuclídeos em sedimento constituam uma ferramenta atraente para estimativa da taxa de denudação de áreas-fonte, a exigência da relação inicial entre a produção e a remoção de nuclídeos torna o método menos óbvio no caso de bacias foreland, nas quais o estoque de sedimento pode alterar os sinais de erosão pelo 10 Be das áreas-fonte. Um modelo de nuclídeos cosmogênicos já publicado afi rma contudo que a concentração dos nuclídeos não é modifi cada pelo estoque temporário de sedimento. No presente trabalho esse modelo foi testado na grande bacia foreland de Beni pela medição das concentrações de nuclídeos de 10 Be em sedimento detrítico de um trecho de 600 km ao longo da planície de inundação do rio Beni. Os resultados revelaram que o sinal da taxa de denudação baseada em de nuclídeos de 10 Be é preservado nos depósitos da planície de inundação do rio Beni, mesmo em setores onde os sedimentos estejam estocados por milhares de anos. Os valores da taxa de denudação por 10 Be encontrad...

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“…Similarly, found that denudation rates for bedrock samples in Namib Desert were lower than catchment-averaged rates from channel sediment samples. In the Yuma Wash basin in southwest Arizona, Clapp et al (2002) used channel sediment samples to compare sediment generation rates for subcatchments as well as the basin as a whole. They found that in the upland subcatchments cosmogenic nuclide concentrations reflect rates of sediment generation from bedrock weathering, whereas sediment in the main channel also includes the long-term effects of sediment storage …”

Section: Catchment-averaged Denudation Ratesmentioning

confidence: 99%

“…and reworking. Further west in the Mojave Desert Nichols et al (2002) have measured cosmogenic 10 Be and 26 Al in sediment samples to document rates and processes of piedmont modification. As well as exploring the spatial variability of denudation rates, catchment-averaged rates derived from cosmogenic nuclide concentrations (which reflect denudation over periods of 10 3 -10 6 years) can usefully be compared with rates derived from modern measurements of river sediment yield.…”

Section: Notesmentioning

confidence: 99%

Geomorphological applications of cosmogenic isotope analysis

Cockburn

Summerfield

2004

Progress in Physical Geography: Earth and Environment

148

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Cosmogenic isotope analysis involves the measurement of cosmogenic nuclides that have accumulated in the upper few metres of the Earth's surface as a result of interactions between cosmic rays and target elements. The concentrations of these cosmogenic nuclides can provide quantitative estimates of the timing and rate of geomorphic processes. In dating applications the concentration of cosmogenic nuclides is interpreted as reflecting the time elapsed since a surface exposure event. However, over most of the Earth's surface for most of the time the landsurface experiences incremental denudation and in these circumstances cosmogenic nuclide concentrations are related to the rate of denudation. Applications of event dating using cosmogenic isotopes include constructional landforms such as volcanic and depositional features, fault displacement, meteorite impacts, rapid mass movement, bedrock surfaces rapidly eroded by fluvial or wave action or exposed by glacial retreat, and the burial of sediment or ice. Strategies for quantifying rates of incremental change include estimates of denudation rates from site-specific samples and from fluvial sediment samples reflecting catchment-wide rates, and measurements of cosmogenic nuclide concentrations in soils and regolith to quantify rates of rock weathering. The past decade has seen a rapid growth in applications of cosmogenic isotope analysis to a wide range of geomorphological problems, and the technique is now playing a major role in dating and quantifying rates of landscape change over timescales of several thousands to several millions of years.

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Quantifying sediment transport on desert piedmonts using 10Be and 26Al

Cited by 62 publications

References 29 publications

From source to sink: Preserving the cosmogenic 10Be-derived denudation rate signal of the Bolivian Andes in sediment of the Beni and Mamoré foreland basins

From source to sink: Preserving the cosmogenic 10Be-derived denudation rate signal of the Bolivian Andes in sediment of the Beni and Mamoré foreland basins

Quantifying sediment discharge from the Bolivian Andes into the Beni foreland basin from cosmogenic 10Be-derived denudation rates

Geomorphological applications of cosmogenic isotope analysis

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