The late Quaternary deglaciation in the central Adriatic basin

Abstract

Preliminary results of a multidisciplinary study on a core collected in the Meso Adriatic Depression (MAD) are discussed. This small basin is 250 m deep and provides a continuous marine section that has recorded climatic changes since the Last Glacial Maximum (LGM). Because of its location very close to a mainland, this relatively-shallow marine section provides a unique opportunity for establishing good correlations between paleoclimatic records on land and in deeper-water regions in the central Mediterranean. Foraminifera and pollen assemblages vary in good agreement showing that the transition from glacial to interglacial conditions was punctuated by several short-term oscillations. In particular, the Younger Dryas cold event is recorded by the return to more arid conditions on land, and by increased productivity and cooling of surface waters. This return to colder conditions is associated with a substantial increase of sediment accumulation rate, probably triggered by a drop in the rate of relative sea-level rise. During the Holocene, major shifts in foraminiferal assemblages reflect the transgressive widening of the Adriatic basin, and the progressive drowning of the southern sill that allowed for a better connection between the basin and the rest of the Mediterranean. The greatest influence of levantine waters on the basin oceanography commenced since 9,500 calibrated 14C years BP. Modern circulation, marked by oligotrophic faunas, was established at about 6,000 calibrated 14C years BP.