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

The Uk′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 Uk′37–temperature relationship. The samples were dominated by small Reticulofenestra (R. minuta and R. minutula) and the C37 and C38 methyl and ethyl unsaturation ratios (Uk′37, Uk38Me and Uk38Et) 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 Uk′37 to that found in present day. These results support the application of the Uk′37 modern calibrations to reconstruct SST at least back in the Pliocene.

Research Highlights
► We have studied the coccolithophorid remains in sediments from the early Pliocene Sicilian Trubi Formation.
► Aim: to assess the influence of changes in the alkenone-producing coccolithophorids on the Uk′37 –temperature relationship.
► The samples were dominated by small Reticulofenestra (R. minuta and R. minutula).
► The C37 and C38 methyl and ethyl unsaturation ratios were similar to those in modern populations.
► Early Pliocene small Reticulofenetrids may have had a similar temperature sensitivity of Uk′37 to that found in present day.