Downstream Enrichment in the Transport and Storage of Sediment Fingerprint Properties

Today fingerprinting techniques are increasingly adopted as an alternative and more direct and reliable means of assembling sediment source information. One of the principal assumptions of sediment fingerprinting is that potential catchment sediment sources canbe distinguished on the basis of their physical, geochemical and biological properties or fingerprint properties. However, while the source fingerprinting approaches necessarily assume conservative behaviour of the fingerprint properties, some in-stream alteration of these properties during both transport and short-term storage is probably inevitable. This potential limitation must be judged in the context of the problems associated with the use of sediment fingerprinting techniques. Samples of sediment source and reservoir sediment collected during the present study have been used to determine the conservative behavior of fifteen fingerprint properties. Comparison of fingerprinting property concentrations of intensive properties used in fingerprinting indicates there is an increase in content of the N, P, C, Co, Cr, clay minerals (smectite, illite, kaolinite), Low Frequency Magnetic Susceptibility (XLF) and Frequency Dependent Magnetic Susceptibility (XFD) and decrease in clay mineral chlorite and base cations Ca, Mg, Na and K. The results indicate that N, Na and smectite properties have no significant difference in reservoir sediment samples than that in sediment source samples and therefore are useful for fingerprinting investigations in these catchments.