@article{PAR00006838,
  title = {{S}ediment production and delivery in the {A}mazon {R}iver basin quantified by in situ-produced cosmogenic nuclides and recent river loads},
  author = {{W}ittmann, {H}. and von {B}lanckenburg, {F}. and {M}aurice, {L}aurence and {G}uyot, {J}ean-{L}oup and {F}ilizola, {N}. and {K}ubik, {P}. {W}.},
  editor = {},
  language = {{ENG}},
  abstract = {{W}e use cosmogenic nuclide-derived denudation rates from in situ-produced {B}e-10 in river sediment to determine sediment production rates for the central {A}mazon {R}iver and its major tributaries. {R}ecent developments have shown that this method allows calculating denudation rates in large depositional basins despite intermediate sediment storage, with the result that fluxes of the sediment-producing hinterland can now be linked to those discharged at the basins' outlet. {I}n rivers of the central {A}mazonian plain, sediment of finer grain sizes (125-500 mu m) yields a weighted cosmogenic nuclide-derived denudation rate of 0.24 +/- 0.02 mm/yr that is comparable to the integrated rate of all main {A}ndean-draining rivers (0.37 +/- 0.06 mm/yr), which are the {B}eni, {N}apo, {M}amore, {U}cayali, and {M}aranon rivers. {C}oarser-grained sediment (> 500 mu m) of central {A}mazonian rivers is indicative of a source from the tectonically stable cratonic headwaters of the {G}uyana and {B}razilian shields, for which the denudation rate is 0.01-0.02 mm/yr. {R}espective sediment loads can be calculated by converting these cosmogenic nuclide-derived rates using their sediment-producing areas. {F}or the {A}mazon {R}iver at {O}bidos, a sediment production rate of similar to 610 {M}t/yr results; non-{A}ndean source areas contribute only similar to 45 {M}t/yr. {A} comparison with published modern sediment fluxes shows similarities within a factor of similar to 2 with an average gauging-derived sediment load of similar to 1000 {M}t/yr at {O}bidos, for example. {W}e attribute this similar trend in cosmogenic versus modern sediment loads first to the absence of long-term deposition within the basin and second to the buffering capability of the large {A}mazon floodplain. {T}he buffering capability dampens short-term, high-amplitude fluctuations (climatic variability in source areas and anthropogenic soil erosion) by the time the denudation rate signal of the hinterland is transmitted to the outlet of the basin.},
  keywords = {},
  booktitle = {},
  journal = {{G}eological {S}ociety of {A}merica {B}ulletin},
  volume = {123},
  numero = {5-6},
  pages = {934--950},
  ISSN = {0016-7606},
  year = {2011},
  DOI = {10.1130/b30317.1},
  URL = {https://www.documentation.ird.fr/hor/{PAR}00006838},
}