title: Attribution of sources to metal accumulation in an alpine tarn, the Snowy Mountains, Australia.
abstract: This study analyses 1800 years of heavy metal accumulation in a remote alpine lake experiencing long-range atmospheric contamination and additional inputs of Ag from cloud seeding. In comparison to previous work undertaken on peats, lake sediments show limited post-industrial metal enrichment with enrichment factors of Ag: 1.3, Pb: 1.3, Zn: 1.1, Cu: 1.2 compared to Ag: 2.2, Pb: 3.3, Zn: 2.1, Cu: 4.1 for peat. We show this to be the result of substantial fluvial lithogenic flux of metals (92-97% of total metal flux) to the lake. Total annual metal flux to the lake ranges from: Ag: 4-12 ng/cm(2)/yr to Zn: 3 383-11 313 ng/cm(2)/yr. As a result, any contribution of cloud seeding to additional enrichment of Ag in lake sediments is considered negligible. Results show that metal enrichment is not necessarily ubiquitous through a landscape. This has implications for predicting the impacts of atmospheric metal pollution to complex environmental systems.
authors.affiliation: Climate Research Group, School of Geography, Planning and Environmental Management, The University of Queensland, St Lucia, QLD 4072, Australia. n.stromsoe@uq.edu.au
authors.forename: Nicola
authors.initials: N
authors.lastname: Stromsoe
authors.forename: J Nikolaus
authors.initials: JN
authors.lastname: Callow
authors.forename: Hamish A
authors.initials: HA
authors.lastname: McGowan
authors.forename: Samuel K
authors.initials: SK
authors.lastname: Marx
mesh_terms: D000531:Altitude; D001315:Australia; D017753:Ecosystem; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000737:chemistry; D060106:Lakes / Q000737:chemistry*; D008670:Metals / Q000032:analysis*; D012914:Snow / Q000737:chemistry; D012987:Soil / Q000737:chemistry
chemical_list: D008670:Metals; D012987:Soil
keywords: Atmospheric pollution; Cloud seeding; Lakes; Metals