Millenial-scale paleoenviromental changes in the central Mediterranean during the Last Interglacial: comparison with European and North Atlantic records.

The environment of the central Mediterranean Sea is investigated on the basis of high-resolution planktonic foraminifera and calcareous nannofossil data (mean sampling resolutions of about 80 and 160 yr, respectively). MIS 5 is characterized by warm, oligotrophic and stratified waters, while coccolithophore communities developed a vertical zonation that, in today's oceans, is typical of the low-latitude gyres. The temperate-subtropical configuration of planktonic foraminifera and calcareous nannofossil assemblages is repeatedly transformed into a temperate-subpolar one during the suborbital cooling episodes C25-C18. A comparison with European pollen sequences and North Atlantic cores over the interval between about 128 and 110 kyr BP is carried out. Records from this broad geographical area show a series of environmental changes that occurred at comparable times. However, the first cooling episodes were more severe at high-latitude (approximately north of 50°N), where an anticipated end of interglacial conditions can be ascribed. Variations in the rate of the Atlantic meridional overturning circulation and the strength of atmospheric circulation in the Northern Hemisphere are discussed as likely climatic forcing mechanisms.