A. Lotter & C. Tzedakis
The importance of providing a chronological framework for all EPD pollen records is once again emphasized. Building on the intentions expressed in the previous newsletter where, if possible, all sites should include at least one chronology, the AB recommends that in addition to a radiocarbon chronology (expressed in conventional radiocarbon years BP) an absolute chronology (expressed in calendar years BP) should be available. Such an absolute chronology will on the one hand enable direct comparisons with other data-sets based on calendar years (e.g. ice cores, insolation, GCM reconstructions, etc). On the other hand, the use of such a sidereal time-scale also provides the opportunity to estimate realistic rates of environmental and ecological change. Unless a varve chronology is available for a site, the conversion to calendar years will be carried out by the EPD in collaboration with the data contributor and will utilize the latest available calibration techniques. The depth-age models (e.g. linear or polynomial interpolation, etc) and the calibration method used to derive the chronologies must be documented in the EPD. The development of accurate chronologies for all pollen records will enable the EPD to realize its full potential and will be paramount for its promotion to a wider scientific community.