Salinity and Climate Reconstructions from Continental Lakes

The species composition of diatoms preserved in lake sediments can be used to infer temporal changes in salinity, driven by changes in the balance between precipitation and evaporation. This approach works best in topographically closed lake basins in arid or semiarid regions that have limited groundwater connections. The reconstruction of past salinity trends from diatoms is based on our knowledge of diatom ecology derived from studying modern lakes, and in most cases, salinity reconstructions can be made with a high degree of confidence. Reconstruction of climate from salinity change relies on a good understanding of the factors that control the hydrologic and ion balance of individual lakes. Diatom-inferred salinity reconstructions have been used to document Quaternary environmental change from modern and ancient lake basins on all the continents and from high to low latitudes. The majority of studies are from the Americas and Africa, where diatoms have been used to document precipitation patterns associated with global temperature, insolation, and sea-surface temperature variation at orbital to decadal time scales.