Gold and arsenic concentrations in plants as an indication of gold mineralisation

A range of plant species growing on derelict gold mines and a lead-silver mine (background site) in Merionethshire, Wales, United Kingdom, was analysed simultaneously for Au and As by neutron activation analysis. The γ-emitting 198Au and 76As isotopes were determined in dried compact plant material following irradiation. Many plant species collected from the gold mines contained Au concentrations significantly above background values, but the extent of Au accumulation varied between and within species. Grasses, and herbs associated with the equatic environment contained the most Au, the highest value recorded was 95 ppb (dry weight) in the leaves of the grass Festuca rubra L. Species which contained high concentrations of Au also contained high concentrations of As. (Auth.)