Establishing a terrestrial chronological framework as a basis for biostratigraphical comparisons

The palynological signature of interglacial deposits in the fragmentary Eur opean terrestrial record has often been used as the basis for determining t heir chronostratigraphical position and ultimately their age. This has plac ed emphasis on the presence/absence and abundance of certain characteristic taxa, but given the lack of continuous stratigraphies and independent chro nologies, it has been difficult to assess the extent to which this strategy has produced reliable schemes. Here, an alternative approach is adopted wh ereby a chronological framework is developed for long and continuous pollen sequences from southern Europe. This in turn allows the emergence of a com plete stratigraphical scheme of major vegetation events for the last 430 th ousand years (ka) and the evaluation of the stage record of different taxa and their potential diagnostic value for biostratigraphical correlation. Th e comparison shows distinct similarities among some temperate stages of the terrestrial equivalent complexes of Marine Isotope Stages (MIS) 5 and 7 an d also of MIS 9 and I I. but examination of combined records of taxa provid es a possibility to differentiate between individual stages. A numerically- derived dichotomous key for the terrestrial stages based on the palynologic al records of 10 taxa is presented. Carpinus. Fagus. Abies, Pterocarya and Buxus emerge as the best 'indicator pollen types' because of their variable behaviour from one stage to the next, possibly a result of their late expa nsion within a temperate stage or reduced genetic variability. The analysis shows that the palynological signature of a temperate deposit can constrai n the range of chronostratigraphical possibilities, but vegetation and paly nological variability arising from local factors could result in difficulti es in making a definite assignment at individual sites. (C) 2001 Elsevier S cience Ltd. All rights reserved.