Historical contaminant fluxes in the Tees estuary, UK: Geochemical, magnetic and radionuclide evidence

Geochemical, magnetic and radionuclide analyses were undertaken on deep and shallow cores from the Tees estuary in an investigation of sediment flux d uring the historical past, using the record of contamination from mining an d industrial activity to link Holocene coastal change with present-day sedi mentary processes. The extent of contamination can be identified from XRF a nd environmental magnetism data, and is variable in magnitude and thickness . Concentrations of Pb and Zn are particularly effective in the identificat ion of far-field mining contamination, whilst As concentration and the conc entration of magnetic minerals (chi, magnetic susceptibility) are used to c haracterise near-field industrial contamination, Radionuclide chronologies (Pb-210 and Cs-137) confirm limited post-depositional disturbance of the sh allow sedimentary record and place the onset of industrial contamination at c, 1925, with a peak level in the mid-1950s, Although contamination has de creased since the early-1980s, the marked spatial and vertical variation in the extent of this contamination adds a significant level of complexity to any future assessment programme where sediment erosion and redistribution are important concerns. (C) 1999 Elsevier Science Ltd. All rights reserved.