Talk by Malin Kylander, Research Fellow, Dept. of Geological Sciences, Stockholm University – Niels Bohr Institute - University of Copenhagen

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Talk by Malin Kylander, Research Fellow, Dept. of Geological Sciences, Stockholm University

By Malin Kylander
Department of Geological Sciences, Stockholm University

Paleorecords of dust provide a means by which we can examine the response of dust over time under very different climatic conditions. Ombrotrophic peat is hydrologically isolated and therefore, like ice, records atmospheric deposition alone and provides continuous, high-resolution, datable records of climate change. The use of peat for reconstructing dust deposition has been demonstrated, but as yet, not systematically examined.
In this presentation the on-going work to test this potential paleo-dust archive is presented. This work is based on a 9000 year old record from Store Mosse in central Sweden. Loss on ignition, in combination with elemental chemistry of the samples, aids in identifying those depths where the observed signal is atmospheric in source only. Humification analyses and bulk density are used as a proxy for surface wetness and allows for the linking of broader climatic changes (precipitation, evaporation, temperature) with fluctuations in dust deposition rates. The inorganic geochemistry provides a means to quantify dust deposition as well as make a first attempt at source tracing of the deposited materials; this is important in terms of reconstructing changes in paleo wind regimes.

Past variations in aeolian activity in Scandinavia are relatively unknown. Dune building records from Denmark and elsewhere around Europe show several periods of inland sand invasion and dune building during the Holocene. These are linked to cooler and stormier climates caused by shifts in the North Atlantic Oscillation and/or movement of the polar front. The dust deposition record from Store Mosse is compared with available dune building records and records of storminess from the region in order to make a preliminary assessment of the use of peatlands as paleorecords of dust deposition.