Use of 210Pb and 137Cs to simultaneously constrain ages and sources of post-dam sediments in the Cordeaux reservoir, Sydney, Australia.
Environmental radionuclides can be employed as tracers of sediment movement and delivery to water bodies such as lakes and reservoirs. The chronologies of sediments that have accumulated in the Cordeaux reservoir in Sydney, Australia, were determined by the rate of change of (210)Pb(ex) with depth and indicate slow accretion in the reservoir. The ratio of enrichment of radionuclides in sediment cores to (210)Pb(ex) and (137)Cs concentrations in a reference soil sample within the Cordeaux catchment indicates that the dominant source of sediment in the Cordeaux reservoir is surface erosion (detachment and removal of sediment at depths less than 30 cm). However, in the Kembla Creek arm of the reservoir a mixture of sources was detected and includes sheet and rill erosion together with sub-soil contributions. Implications for the utility of these radionuclide sedimentation assessments, especially where samples are limited, are that well-constrained chronologies and sources of soil erosion are facilitated.
Simms
Ava D
AD
GeoQuEST Research Centre, School of Earth and Environmental Sciences, University of Wollongong, Northfields Avenue, Gwynneville, NSW 2522, Australia. ads94@uow.edu.au
Woodroffe
Colin
C
Jones
Brian G
BG
Heijnis
Henk
H
Mann
Rob A
RA
Harrison
Jennifer
J
D001315:Australia; D002588:Cesium Radioisotopes / Q000032:analysis; D004784:Environmental Monitoring / Q000379:methods*; D005843:Geography; D019015:Geologic Sediments / Q000032:analysis*; D007856:Lead Radioisotopes / Q000032:analysis; D045483:Rivers; D014875:Water Pollutants, Radioactive / Q000032:analysis*
D002588:Cesium Radioisotopes; D007856:Lead Radioisotopes; D014875:Water Pollutants, Radioactive