The potential for palaeoclimate records from varved Arctic lake sediments: Baffin Island, eastern Canadian Arctic

Tidewater lakes on Baffin Island in the eastern Canadian Arctic offer an excellent opportunity to study interannual to century-scale Arctic climatic change. Freeze-cores were analysed for three lakes in southeastern Baffin Island. The sediment record in each lake consists of massive sediments overlain by an organic-rich, finely laminated section which continues to the surface. The laminae in Ogac Lake were studied in detail and consist of two types. These couplets are probably deposited as the result of diatom blooms in the late spring/summer growing season followed by settling of grains introduced by summer runoff. Sedimentation rates based on ²¹⁰Pb dates agree well with rates based on laminae counts in both Ogac and Winton Bay Lakes, indicating that the laminae couplets are annually deposited varves. Shallow-silled tidewater lakes with varved sediments may be relatively common along the coast of Baffin Island. It should thus be possible to create a network of sites with annually dated palaeoclimate records.