Funds are provided to apply the stable isotope techniques pioneered by the principal investigators for Axel Heiberg terrestrial fossils across a Trans-Arctic trajectory of Eocene field sites. The principal investigators will retrieve fossil materials from the Eastern High Arctic (Axel Heiberg and Ellesmere Island; 2008), the Western High Arctic (Banks Island; 2009), and near Anchorage, Alaska (2010). Fieldwork and the resulting analyses of sediments and plant/vertebrate fossils across these sites will provide global quantification of Eocene northern high-latitude paleoclimate. In addition to the ä13C, ä18O and äD techniques pioneered for fossil wood, cellulose, resin, organic matter and carbonate, they will apply two new chemical techniques: the use of ä18O in phenylglucosazone derived from cellulose to imply the oxygen isotope composition of environmental water, and the use of lipid biomarkers known as glycerol dialkyl glycerol tetraethers (GDGTs) to infer soil temperature. They anticipate that their analyses will yield a quantification of organismal carbon-cycling, soil temperature, atmospheric relative humidity, environmental water source and inference of weather pattern, across a global Eocene Arctic transect. These analyses are specifically designed to exploit the exceptionally well-preserved terrestrial organic compounds of the mummified trees and litter layers within Arctic Eocene sediments.
