Rapid climate change during the last glacial–interglacial transition; implications for stratigraphic subdivision, correlation and dating

The frequent and often abrupt climatic changes that occurred during the transition from the last cold stage to the present interglacial (the ‘Late-glacial period’) pose particular problems for stratigraphy and correlation, while difficulties are also encountered in developing a coherent independent dating framework for this important time interval. It has been recommended that the Greenland GRIP ice core should constitute a stratotype for the late Pleistocene, and that stratigraphic sequences should be correlated with the GRIP oxygen isotope signal on the basis of climatically defined ‘events’. Three approaches to the development of quantified climate records (using pollen, coleopteran and chironomid data) are examined and links to the GRIP ice core discussed. Despite its limitations, radiocarbon remains the most universal method for establishing a timescale for the Late-glacial, and the paper concludes with a discussion of an experimental approach designed to establish the reliability and comparability of Late-glacial radiocarbon dates. Evaluatory exercises of this nature are now required if radiocarbon dating is to provide the necessary high-resolution chronology for time-stratigraphic correlation between terrestrial sequences, marine records and the GRIP stratotype.