Quantitative Paleoclimate Reconstructions from the Melville Peninsula, Nunavut, Canada

A transitional climate and the presence of Thule sites make the Melville Peninsula an area of high importance for paleoenvironmental studies. Lake sediment cores and surface samples from Melville Peninsula were analyzed for diatom assemblages. Fragilarioid diatom species dominate assemblages from the interior of the peninsula since the middle Holocene. The greatest changes in diatom communities occurred during the transition from the Holocene Thermal Maximum to the Neoglacial, and in the post-Little Ice Age period. Species richness reached maximum values in the most recent period, reaching 50.8 species in surface sediments. Diatom-inferred pH reconstruction from two lakes did not indicate substantial change throughout the Holocene despite assemblage changes, showing the complexity of interpreting paleoclimate records dominated by Fragilarioids. Analysis of modern assemblages from the interior and East coast of Melville Peninsula confirm the importance of site size and water chemistry, as determined by bedrock geology, in determining diatom species distributions.MAS