Barks from the litters of a multiple level Tertiary fossil forest from the Canadian Arctic were chemically examined and compared with coeval Arctic fossil woods. Degradation and diagenesis of the polysaccharides similarly occurred in barks and woods. However, unlike the fossil woods, the loss of polysaccharides led to materials exhibiting a marked cation exchange capacity, which is comparable to what is found for humus, the final product of diagenesis of the forest litter. Dichloromethane extracts from the barks invariably showed the presence of n -alkanes from C14 to C30, and terpenes such as cadalene, calamenene, fichtelite, sandaracopimarane, abietatriene, simonellite, diaromatic totarane, ferruginol, dehydroferruginol, and sugiol. The presence of phenol-diterpenes and/or diaromatic totarane was related to species belonging to Cupressaceae, Taxodiaceae and Podocarpaceae, in agreement with the recovery of trunks of metasequoia in some forest levels.