Reservoir sediments – a witness of mining and industrial development (Malter Reservoir, eastern Erzgebirge, Germany)

摘要: The Malter Reservoir is situated about 30 km south of Dresden (eastern Germany) in a historical mining area the eastern Erzgebirge. It was built 1913 for protection from floodwaters, droughts and generating electricity. river Rote Weiseritz main source clastic input into lake. Geochemical sedimentological data gravity-and piston-cores, recovered deepest point lake, document environmental history drainage since 1963. 137Cs dating gives an average sedimentation rate ∼2.9 cm/year. Within whole core, heavy metals are strongly enriched (parentheses refer to enrichment factors as compared with shale): cadmium (290), silver (140), bismuth (90), antimony (25), lead (21), zinc (14), tin (13), uranium (9), tungsten molybdenum (5), copper (4), thallium (3) chromium (2). Enrichments detectable registered time-period 81 years. Peaks up 27 mg/kg silver, 37 bismuth, 91 cadmium, 410 chromium, 240 copper, 20 molybdenum, 14000 phosphorus, 740 lead, 6,5 antimony, 74 tin, 52 1900 reflect local events caused by human impact. Inputs different pollution sources at times represented highly variable elemental concentrations ratios within core. High pH values water sediment column, large adsorption capacity fine-grained Corg.-rich sediment, presence low Eh-values sulphide ions prevent remobilisation toxic elements. Erosion these contaminated sediments during floods, channel flows or resuspension removal may downstream transfer pollutants. Contents P Corg., well diatom abundance, indicate change oligotrophic eutrophic conditions lake ∼1940–1950. This mainly high agricultural activity area. Reduced contents Cu, Zn, Cd Cr reunification East West Germany obviously increasing measures, such wastewater purification especially closing contaminating industries.