The Importance of Eolian Input on Lake-Sediment Geochemical Composition in the Dry Proglacial Landscape of Western Greenland

Abstract

ABSTRACTIn proglacial landscapes, such as western Greenland, eolian transport plays an important role for the influx of particulate material to lakes. On the basis of an analysis of a sediment profile and surface sediments from several lakes, we show that eolian activity has a strong influence on sediment deposition in time and space. Principal component analysis revealed that sediments that accumulated during periods with high eolian activity were enriched in zirconium—originating from coarse silt and sand fractions preferentially transported by wind—and depleted in rubidium. In addition, zirconium to rubidium ratios in the surface sediment of four additional lakes decreased with distance from the ice sheet. Finally, previously published data show that pH and alkalinity tend to be higher in lakes close to the front of the ice sheet, which we speculate is coupled to a larger supply of fresh eolian material. These findings demonstrate that lakes in proglacial landscapes may receive a substantial part of their sediment load through eolian deposition, and that this is especially true close to the glacial outwash plains along the ice margin.