Mid- and late Holocene dust deposition in western Europe: the Misten peat bog (Hautes Fagnes – Belgium)
Résumé
Dust deposition in southern Belgium is estimated from the geochemical signature of an ombrotrophic peatland. The rare earth elements (REE) and lithogenic elements concentrations, as well as Nd isotopes, were determined by HRICP- MS and MC-ICP-MS, respectively, along an ~6m peat section covering 5300 yr, from 2000 to 7300 cal BP, dated by the 14C method. Changes in REE concentration in the peat correlate with those of Ti, Al, Sc and Zr that are lithogenic conservative elements, suggesting that REE are immobile in the studied peat bogs and can be used as tracers of dust deposition. Peat humification and testate amoebae were used to evaluate hydroclimatic conditions. The range of dust deposition varied from 0.03 to 4.0 gm−2 yr−1. The highest dust fluxes were observed from 2750 to 2550 cal BP and from 5150 to 4750 cal BP, and correspond to cold periods. The "Nd values show a large variability from −13 to −5, identifying three major sources of dusts: local soils, distal volcanic and desert particles.
Origine : Fichiers produits par l'(les) auteur(s)
Loading...