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Single-grain cosmogenic 21Ne concentrations in fluvial sediments reveal spatially variable erosion rates

Journal Article


Abstract


  • We evaluated the hypothesis that the spatial variation in erosion in a catchment is reflected in the distribution of the cosmogenic nuclide concentrations in sediments leaving the catchment. Using published data and four new 10Be measurements in fluvial sediment collected from the outlets of small river catchments, we constrained the spatial variability of erosion rates in the Gaub River catchment in Namibia. We combined these catchment-averaged erosion rates, and the mean slope values with which they are associated, in a digital elevation model (DEM)–based analysis to predict distributions of cosmogenic 21Ne concentrations in the sediment leaving the Gaub catchment. We compared these synthetic distributions with the distribution of concentrations of cosmogenic 21Ne (21NeC) in 32 quartz fluvial pebbles (16–21 mm) collected from the catchment outlet. The 21NeC concentrations span nearly two orders of magnitude (2.6–160 × 106 atoms/g) and are highly skewed toward low values. The DEM-based analysis confirms this skew—the measured 21NeC distribution plots within the envelope of distributions predicted for the catchment. This match between measured and synthetic 21Ne distributions implies that the measured distribution is a signature of the spatial variation in erosion rates.

Authors


  •   Codilean, Alexandru Tiberiu.
  •   Bishop, Paul (external author)
  •   Stuart, Finlay M. (external author)
  •   Hoey, Trevor B. (external author)
  •   Fabel, Derek (external author)
  •   Freeman, Stewart P.H.T. (external author)

Publication Date


  • 2008

Citation


  • Codilean, A. T., Bishop, P., Stuart, F. M., Hoey, T., Fabel, D. & Freeman, S. P.H.T. (2008). Single-grain cosmogenic 21Ne concentrations in fluvial sediments reveal spatially variable erosion rates. Geology (Boulder), 36 (2), 159-162.

Scopus Eid


  • 2-s2.0-44449106116

Ro Metadata Url


  • http://ro.uow.edu.au/smhpapers/1512

Number Of Pages


  • 3

Start Page


  • 159

End Page


  • 162

Volume


  • 36

Issue


  • 2

Abstract


  • We evaluated the hypothesis that the spatial variation in erosion in a catchment is reflected in the distribution of the cosmogenic nuclide concentrations in sediments leaving the catchment. Using published data and four new 10Be measurements in fluvial sediment collected from the outlets of small river catchments, we constrained the spatial variability of erosion rates in the Gaub River catchment in Namibia. We combined these catchment-averaged erosion rates, and the mean slope values with which they are associated, in a digital elevation model (DEM)–based analysis to predict distributions of cosmogenic 21Ne concentrations in the sediment leaving the Gaub catchment. We compared these synthetic distributions with the distribution of concentrations of cosmogenic 21Ne (21NeC) in 32 quartz fluvial pebbles (16–21 mm) collected from the catchment outlet. The 21NeC concentrations span nearly two orders of magnitude (2.6–160 × 106 atoms/g) and are highly skewed toward low values. The DEM-based analysis confirms this skew—the measured 21NeC distribution plots within the envelope of distributions predicted for the catchment. This match between measured and synthetic 21Ne distributions implies that the measured distribution is a signature of the spatial variation in erosion rates.

Authors


  •   Codilean, Alexandru Tiberiu.
  •   Bishop, Paul (external author)
  •   Stuart, Finlay M. (external author)
  •   Hoey, Trevor B. (external author)
  •   Fabel, Derek (external author)
  •   Freeman, Stewart P.H.T. (external author)

Publication Date


  • 2008

Citation


  • Codilean, A. T., Bishop, P., Stuart, F. M., Hoey, T., Fabel, D. & Freeman, S. P.H.T. (2008). Single-grain cosmogenic 21Ne concentrations in fluvial sediments reveal spatially variable erosion rates. Geology (Boulder), 36 (2), 159-162.

Scopus Eid


  • 2-s2.0-44449106116

Ro Metadata Url


  • http://ro.uow.edu.au/smhpapers/1512

Number Of Pages


  • 3

Start Page


  • 159

End Page


  • 162

Volume


  • 36

Issue


  • 2