Caterina BERGAMI, Lucilla CAPOTONDI, Daniela Salvagio MANTA, Mario SPROVIERI & Luigi VIGLIOTTI
Temperature variations during the Holocene sapropel S1 has been investigated by means of a multiproxy study on core ET99-M11 collected in the western Ionian Sea at a water depth of 2800 m. Sea Surface Temperatures (SST) reconstruction has been made by measuring oxygen stable isotopes (δ18O) and Mg/Ca ratios on the planktonic foraminifers Globigerinoides ruber and Globigerina bulloides. Results indicate that the investigated interval was characterized by water temperature increase, both at surface and in the sub-surface layers. Paleotemperature reconstruction based on Mg/Ca ratios shows higher temperature values during the two sub-units (S1a and S1b) of the sapropel S1, and lower during the sapropel interruption, the latter being synchronous to the well known 8.2 cold event. In addition, a number of several short-term cold oscillations which can be correlated with millennial scale climate events in the North Atlantic region is evidenced. This indicates a possible atmospheric connection between the Central Mediterranean and the North Atlantic region and the strong relation between climate and oceanographic changes during the sapropel deposition.
sapropel S1, planktonic foraminifera, paleotemperature, Central Mediterranean, Mg/Ca.