The geological significance of cosmogenic nuclides in large lowland river basins

Finally, we provide a short introduction to the use of meteoric cosmogenic nuclide 10Be and its ratio to stable 9Be, released by rock weathering, in lowlands. In the Amazon basin we show that 10Be concentrations in fine-grained suspended loads, depth-integrated over the water column using Al/Si ratios, provide erosion rates whereas the 10Be/9Be ratio on Be adsorbed to particles provides the denudation rate. Both are similar to denudation rates from in situ 10Be. We show that this system responds more sensitively to sediment storage than the in situ system, and both accumulation and decay of meteoric concentrations may thus be used to determine sediment residence time.