A geochemical record of the mining history of the Erme Estuary, south Devon, UK

摘要

The concentration of selected trace metals (Cu, Pb and Zn) in salt-marsh sediments from within the Erme Estuary have been measured in order to assess possible historical sources of pollution. The Erme Estuary, south Devon, UK is an Area of Outstanding Natural Beauty and has remained largely unaffected by industrialisation, although a number of small silver-lead mines were in oper-ation in the 1800s. Five cores reveal comparable geochemical profiles. An increase of lead at ～40 cm depth is observed, reaching maximum values of 427 ppm. Less distinct trends are revealed by zinc and copper, probably reflecting the lack of widespread mining for ores of these elements within the catchment and possible post-depositionaL mobility rendering the metal concentrations non-con-temporaneous with the chemostratigraphy of lead. The geochemical analysis of the salt-marsh sediments provides a fairly robust chemostratigraphic scheme and the likely sources of mine waste can be pinpointed within the catchment. Based upon reference to the historical mining record of these mines chemostratigraphic dating of the sediments can be achieved in order to provide an estimate of salt-marsh accretion rates and sea-level rise.