Reconstruction of Palaeogene climate from palynological evidence

Abstract

Multivariate statistical analysis of Palaeogene (early Tertiary) pollen and spore spectra from north-west Europe allows the identification of four major groups of taxa¹. Three are thought to include the Palaeogene equivalents of taxa now found in deciduous forest, fern and conifer forest and paratropical rain forest. The other is a rubbishbin of plant taxa reflecting the influences of transport and catchment processes. We have disentangled these effects from the ecological processes and, by analogy with plant megafossil evidence, obtained estimates of summer maximum and winter minimum temperatures, as well as estimates of mean annual temperatures. The resulting picture of climatic fluctuations in the Palaeogene can be recognized in localities throughout north-west Europe. We show here thai the general similarity to results of oxygen isotope analyses from deep-sea cores² and the North Sea³ suggests that genuine global climatic changes are being detected. Major differences between ‘Oligocene’ and ‘Eocene’ climates are also suggested by these reconstructions and support conclusions from other evidence⁴.