Je. Rae et Jrl. Allen, THE SIGNIFICANCE OF ORGANIC-MATTER DEGRADATION IN THE INTERPRETATION OF HISTORICAL POLLUTION TRENDS IN-DEPTH PROFILES OF ESTUARINE SEDIMENT, Estuaries, 16(3B), 1993, pp. 678-682
The quantitative significance of organic matter degradation in bringin
g about the early diagenetic mobility of anthropogenic trace metals (C
u, Zn, Pb) is assessed specifically in relation to the use of estuarin
e sediments as historical records of pollution. A 1,500 mm salt-marsh
sediment depth profile from Tites Point, Severn Estuary, England, was
sampled at 10-mm intervals. Organic carbon determinations were carried
out by a wet oxidation technique, and 'organic fraction' metals were
separated by sequential leaching. Results demonstrated that organic ph
ase metals are quantitatively significant in Severn Estuary sediments,
particularly Cu and Zn (Cu > Zn), and that metals are probably releas
ed from this fraction during early diagenesis. The degree of release,
and the apparent loss of the released trace metals from the sediment,
would suggest that the use of estuarine sediments as historical record
s of pollution requires qualification.