Amazon River sediments accumulation

A summary of physical and biochemical parameters for the Amazon shelf are presented in Table 17.1. These data were used to develop the mass balance calculations described in the remainder of the paper. The rate of Amazon River sediment discharge that is cited in most studies (Meade et al. 1985) characterizes the flux at Obidos, which is hundreds of kilometers from the river mouth. The sediment fluxes that have been documented for the Amazon coastal area are the fine-grained sediment accumulation rate on the shelf (6.3 x 10 g yr, Kuehl et al. 1986, 1996) and the advection rate of particulate material northward out of the study area, primarily in nearshore environments (-1.2 X 10 g yr, Allison et al. 1995). Because some sediment may be deposited between Obidos and the river mouth, we have chosen to use the sum of the shelf... 

Figure 2.10 Sediments accumulation rates (cm y 1) on Amazon River shelf. (From Kuehl et al., 1986, with permission.)...

As part of an analysis of exchanges of sediment between the floodplain and channel of the Amazon River in Brazil, Dunne et al. (1998) calculated the amount of suspended sediments accumulating on a decadal time scale on the floodplain along the reach of the Amazon River from about 52 to 68 W. They used two different approaches and estimated a net transfer of 209 Mt yr i and 500 Mt yr i of sediments from the river to the floodplain. 

McKee BA, DeMaster DJ, Nittrouer CA (1983) Concepts of sediment deposition and accumulation applied to the continental shelf near the mouth of the Yangtze River. Geol 11 631-633 McKee BA, DeMaster DJ, Nittrouer CA (1986a) Temporal variability in the partitioning of thorium between dissolved and particulate phases on the Amazon shelf - implications for the scavenging of particle-reactive species. Cont Shelf Res 6 87-106... 

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