A HIGH-RESOLUTION RECORD OF THE LAST DEGLACIATION IN THE CENTRAL MEDITERRANEAN SEA - PALAEOVEGETATION AND PALEOHYDROLOGICAL EVOLUTION

A high-resolution palynological and stratigraphical record of a marine deep-sea core in the Adriatic sea documents marine and continental pa laeoenvironmental changes in the basin during the last deglaciation an d early Holocene. A chronology is derived from the oxygen isotope stra tigraphy. Three periods of aridity, marked by the development of a sem i-desert rich in Artemisia, occurred between 18.5 and 16 kyr, between 14.4 and 12.7 kyr and between 11.1 and 9.7 kyr, consistent with the La st Glacial Maximum, the Oldest Dryas and the Younger Dryas. They are c orrelated with increases in productivity and intensification of the Le vantine water formation in the Eastern Mediterranean basin. During the warmer Bolling/Allerod (12.7-11.1 kyr), the presence of the cold temp erate dinocyst Bitectatodinium tepikiense is interpreted as indicating the establishment of a strong seasonal thermal gradient, probably lin ked to seasonal cold freshwater runoff from the Po river, attested by the unique presence of pollen of freshwater plants. The expansion of f orest and the development of the warmer dinocysts start with Terminati on IB. During the Holocene, three tree phases are recognized and are c ontemporaneous with the Preboreal, Boreal and Atlantic chronozones of Europe. The two phases of sapropel deposition are marked by higher pol len and dinocyst concentrations and a high representation of Briganted inium spp which indicate higher preservation of organic material and/o r freshwater runoff of the Po River. (C) 1998 Elsevier Science Ltd. Al l rights reserved.