A chronostratigraphic comparison of Late-Weichselian and Late-Devensian subdivisions, illustrated by two radiocarbon-dated profiles from western Britain

¹⁴C-dated percentage and absolute late-glacial pollen diagrams from (1) Blelham Bog, north-west England and (2) Cam Loch, north-west Scotland arc subdivided into chronozones Bølling, Older Dryas, Allerød, and Younger Dryas as proposed for the Late-Weichselian sequence by Mangerud et al., Boreas 3 (1974), with boundaries defined in conventional ¹⁴C years. It is shown how these chronozone boundaries coincide in the two British pollen diagrams with boundaries between pollen assemblage zones which are interpreted as the results of environmental (climatic) changes. Differences between the pollen zones found in western Britain and those of the classic South Scandinavian profiles, which are interpreted as the consequence of regional differentiation in the vegetation of north-west Europe circa 14,500 to 10,000 years ago, pose serious problems in the correlation of Late-Weichselian and Late-Devensian subdivisions on the basis of pollen assemblage zones, but a chronostratigraphical classification makes it possible to compare the Late-Devensian profiles from western Britain with the Late-Weichselian subdivisions of Mangerud et al., in which 'chronozone boundaries seem to be climatically conditioned within southern Scandinavia'.