| Popis: |
The planktonic foraminiferal assemblages found in three cores from the Tyrrhenian Sea and in one core from the Adriatic Sea provide a climatic sequence ranging from the last interglacial to the Holocene. The data have been treated by the Correspondence Factor Analysis method. We propose an interpretation of the three first factors: • - Factor I is thermal. Its influence is clearer in the Tyrrhenian Sea than in the Adriatic Sea where the warm maxima are always less important. • - Factor II probably depends on salinity. • - Factor III seems to be linked with an Atlantic water property and may reflect the influence of this water mass in the different Mediteranean areas. The alternating occurrence of Atlantic subtropical species (in interstadial periods) and of an Atlantic temperate form (at the beginning of the cooling periods) is interpreted as reflecting circulation changes in the Atlantic Ocean (gyre diameter, polar front location). In the Tyrrhenian Sea, the planktonic microfauna is very homogeneous in the different sectors during the Postglacial. However, during stage 5, there are some differences between southern and northern assemblages. This fact suggests that the circulation was different during these two warm periods. In the Adriatic Sea, we note a hydrological shift at about −25,000 yr B.P. |
