Paleolimnology

Paleolimnology involves the reconstruction of historical changes in lakes through the analysis of material preserved within the sediments. The types of questions we address with paleolimnological investigations include:

• What are the rates of sediment accumulation?
• How is the sediment chemistry changing?
• What evidence is there to indicate changes in water quality? Changes in algae?

To address these questions we collect lake sediment using one of several types of coring devices, section the material, and sequentially analyze the intervals. The results provide a chronology of changes in the lake derived from the analysis of the following:

• 210Pb - dating, up to ~ 130 YBP
• 137Cs - dating, since ~ 1960
• 14C - dating, long-term
• C, N, P, Si - nutrients, eutrophication
• Fe, Mn, Al, Ti, Hg - metals, watershed/atmospheric inputs, redox conditions
• Diatoms - water quality indicators
• Akinetes - cyanobacteria
• Pollen - terrestrial/aquatic plants
• Charcoal - fire history
• Chironomids & Cladocerans - water quality, fish predation