LATE PALEOCENE-EARLY EOCENE CLIMATES OF WESTERN AND ARCTIC CANADA

Paleogene megafloras (i.e. leaf assemblages) and microfloras (i.e. spore-pollen) are known from all of the western provinces of Canada, and from the Arctic Archipelago. Current stratigraphic resolution does not allow recognition of any of these fossil floras as directly representing the Paleocene-Eocene Thermal Maximum (PETM) or other Paleogene hyperthermal events. Nonetheless, these floras do show evidence of climatic shifts across mid- to high-northern latitudes and of associated changes in forest community organization. The Paleocene is well represented by floras from Alberta and Saskatchewan, with minor floras known from Manitoba. Floras from British Columbia principally span the early to middle Eocene. Floras in the Arctic, however, span the Paleocene to middle Eocene. These fossil floras reflect extensive forests composed of deciduous angiosperms and both evergreen and deciduous gymnosperms, extending over 30° of latitude. Uneven sampling complicates interpretation of the effects of early Paleogene hyperthermal events, and other climatic changes on mid- and high-latitude vegetation. Nonetheless, a combination of leaf physiognomic analysis and quantitative NLR analysis indicated upper microthermal to lower mesothermal climates for most floras, although a cooler phase was reconstructed for part of the early Eocene. This paper reports on ongoing analyses of combined megafloral and microfloral (i.e. spore-pollen) analyses of Paleogene climates for mid- to high-northern latitudes.