Late Quaternary palaeoenvironmental reconstruction of the Ionian Sea in the eastern Mediterranean.

Abstract

Three eastern Mediterranean deep-sea cores, all from the Ionian Sea, have been investigated to assess late Quaternary palaeoenvironmental change. The high resolution record of planktonic foraminiferal variations for the three Ionian Sea deep cores provides a significant insight into the late Quaternary in relation to palaeoenvironmental and palaeoclimatic conditions. The timing of climatic events is further strengthened by a Sea Surface Temperature (SST) reconstruction based on the utilisation of the transfer function, Artificial Neural Network (ANN) and the calibration dataset of Hayes et al. (2005). Radiocarbon (14C) gives an absolute age of planktonic foraminiferal shell formation within the late Pleistocene and Holocene. The Ionian Sea palaeoenvironmental reconstruction allowed the presentation of four distinct time frames, the late Pleistocene (~20,000-13,000 cal yrs BP), the glacial/interglacial transition (~13,000-9,000 cal yrs BP), Sapropel 1 (~9,000-6,000 cal yrs BP) and the late Holocene (~6,000 to present cal yrs BP). High concentrations of warm water planktonic foraminiferal species, in particular G. ruber, is evident throughout the Holocene and late Pleistocene. A general consistency in the fluctuation of cold water species is observed in the faunal assemblages from the Ionian Sea during the late Pleistocene. Overall, a general cooling is observed from the start of the record, with a pronounced temperature increase at the beginning of the Holocene. Comparison of the intervals and climatic events shows some correlation with other eastern Mediterranean studies, however, some discrepancies have also been observed.