LATITUDINAL CLIMATIC GRADIENTS IN THE WESTERN EUROPEAN AND MEDITERRANEAN REGIONS FROM THE MID-MIOCENE (C. 15 MA) TO THE MID-PLIOCENE (C. 3.5 MA) AS QUANTIFIED FROM POLLEN DATA

Abstract

In Europe and the Mediterranean region, the vegetation and climate of the Neogene is well understood, due to the abundance of pollen data, allowing the climate evolution at a time of global cooling to be described. This paper presents a climatic reconstruction of four key time- slices of the Neogene: the Mid-Miocene (c. 14 Ma), the Late Miocene (c. 10 Ma), the Early Pliocene (c. 5- 5.3 Ma) and the Mid-Pliocene (c. 3.6 Ma). The results show that Neogene climate was warmer than today and that the transition from a weak latitudinal thermic gradient (around 0.48 8C/degree in latitude) to a gradient similar to that of today (0.6 8C/degree in lati- tude) took place at the end of the Miocene. The latitudinal precipitation gradient was more accen- tuated than today from the Mid-Miocene to the Mid-Pliocene, with higher precipitation than today in northwestern Europe and the northwestern Mediterranean but with conditions that were drier than or equivalent to today in the southwestern Mediterranean region.