Characterisation of river bed and suspended sediments in the Rio Madeira drainage basin (Bolivian Amazonia)

The grain size distribution of river bed sediments in the Rio Madeira drain age basin shows rapid deposition of the coarser material (> 10 mm) as the r iver flows out of the Andean range to enter the Amazon plain (Llanos). In t he Andes, the suspended sediment grain size varies between 0.02 and 0.10 mm in diameter, while in the Llanos the suspended load is dominated by fine s ilts, between 7 and 13 mu m in diameter. In the Llanos, neither the bed sed iment nor the suspended sediment varied along a 800 km reach. (C) 1999 Else vier Science Ltd. All rights reserved.