Late Pleistocene dust imprint in coastal dune archives spanning from the Canary to the Tyrrhenian Basin - Preliminary results

Saharan dust input is a well-known phenomenon worldwide but especially concerning landscapes around the Mediterranean Sea and on the Canary Islands since the largest dust source areas on earth are located in the Northern African continent. This dust transport is not just a recent process but has also been going on for the last glacial period with changing intensities. The availability of dust depends mainly on the vegetation cover in the source areas as well as changing wind strengths/pathways and is therefore a function of changing climate. Its effects have been imprinted in several geoarchives and are also well known from aeolianites. These coastal dune archives typically form in dependence of changes in sea level and are comprised of pale coloured carbonate sands, intercalated by reddish silty layers. The reddish silty layers are heavily influenced by dust imprint from the Northern African continent. The presented research project hence focuses on conducting detailed analyses on those layers to reconstruct the local and supraregional environmental conditions during the last glacial.
Our sites on the eastern Canary Islands (Lanzarote, Fuerteventura), SE-Spain, Balearic Islands (Formentera, Eivissa) and Sardinia offer best conditions to
(i) Analyse site-specific characteristics of the dust enriched layers and the stored information about the local environmental conditions,
(ii) Look for differences or systematical similarities in terms of quantities and admixture of dust material when comparing the different silty layers within a single site/profile,
(iii) Identify distinct source areas of dust as well as dominating dust pathways and
(iv) Correlate the different sites from the Canary to the Tyrrhenian basin and deduce supraregional patterns.
So far we conducted extensive fieldwork at all sites and realised a variety of laboratory analyses on samples from the Balearic Islands, for example grain-size specific heavy mineral, XRF-, XRD- and grain-size analysis. With our first results we identified dust enriched layers and utilised analysis of heavy mineral compositions as an additional method to trace possible dust source areas. With this we hope to contribute to the understanding of the large-scale development in the Western Mediterranean region and the Canary Islands during the last glacial.