Long chain alkenones in the Early Pliocene Sicilian sediments (Trubi Formation — Punta di Maiata section): Implications for the alkenone paleothermometry

Abstract

The U k′ 37 record and coccolithophorid remains in sediments from the early Pliocene Sicilian Trubi Formation (Punta di Maiata) have been estimated to assess the possible influence of changes in the alkenone-producing coccolithophorids on the U k′ 37–temperature relationship. The samples were dominated by small Reticulofenestra ( R. minuta and R. minutula) and the C 37 and C 38 methyl and ethyl unsaturation ratios (U k′ 37, U k 38Me and U k 38Et) were similar to those found in modern populations ( E. huxleyi and G. oceanica). Those results suggest that the Early Pliocene small Reticulofenetrids had a similar temperature sensitivity of U k′ 37 to that found in present day. These results support the application of the U k′ 37 modern calibrations to reconstruct SST at least back in the Pliocene.