Oligocene deep ocean oxygen isotope variations primarily driven by temperature.

ABSTRACT: Our understanding of the long-term behaviour of global climate and the Antarctic ice sheet relies heavily on the oxygen isotopic composition of marine calcite (δ¹⁸O_calcite), which reflects a combination of ocean temperature and the amount of water stored in ice sheets. On the basis of δ¹⁸O_calcite, the Antarctic ice sheet has been interpreted as extremely dynamic in the Oligocene, 34-23 million years ago. Yet, the proposed continental-scale ice volume changes are challenging to reproduce with models and may be overestimated owing to a larger influence of temperature on the deep-sea δ¹⁸O_calcite than previously assumed. Here we present the first Oligocene record of orbital variability in deep ocean temperature based on benthic

SUBMITTER: Boscolo-Galazzo F 

PROVIDER: S-EPMC12893918 | biostudies-literature | 2026

REPOSITORIES: biostudies-literature