Planktonic foraminifera and quantitative paleoclimatology of the Eastern Mediterranean

Paleoclimatic trends exhibited by assemblages of planktonic foraminifera in samples of two cores from the Mediterranean continental slope of Israel are similar regardless of the size fraction used in counting (larger than 76 μm or larger than 149 μm). Application of a North Atlantic-based transfer function (F13) to the counts of the fraction greater than 149 μm reveals that in all the samples the tropical assemblage is dominant. Higher-latitude assemblages occur in the lower portion of one of the two cores which were studied. Stratigraphic correlation of this core with other Eastern Mediterranean cores suggests that its lower part was deposited at the end of the last Glacial. Paleoclimatic estimation was done by the application of the transfer function. The estimates of winter temperature and salinity thus derived from Recent sediment (core-top) differ from values actually observed. It is suggested that this results from inadequate calibration of the transfer function, and that a Mediterranean-based transfer function might be more reliable. The estimated summer temperature in Recent samples is closer to the observed values and, therefore, estimates of the summer temperature are probably more reliable than either of the winter temperature or of salinity. Based on the estimated summer temperature, the change from the late last Glacial to the Recent is small and does not exceed 2°C.