EFFECTS OF LATE PLEISTOCENE-HOLOCENE CLIMATIC CHANGES ON THE PLANKTONIC FORAMINIFERA IN THE GULF OF GAETA (TYRRHENIAN SEA, ITALY)

Abstract

Planktonic foraminiferal assemblages of core G93-C9, recovered in the Gulf of Gaeta (Tyrrhenian Sea) at 212 m of depth, were analysed by Principal Components Analysis. The analysis was computed first on raw percentage data and then on logratio transformed data.
The most important difference between raw data and logratio data rests in the behaviour of N. pachyderma which in the first case,
unlike the second, does not have significant loading on the first component. Sea surface temperatures exerted a strong control on foraminiferal assemblages. Hydrography and productive system also played an important role in determining composition of assemblages, as shown by the loadings of grazing species on the second component. During the last deglaciation and the Early Holocene eutrophic conditions allowed Globorotalia inflata to expand its distribution toward surface waters of the Gulf of Gaeta. During the Late Holocene, planktonic foraminiferal assemblages evidence a tendency towards oligotrophic conditions.