The Eocene–Oligocene Climate Transition in the Southern Tethys: Calcareous Nannofossil Response and Element Geochemistry

Abstract

The late Eocene—Early Oligocene transition is characterized by the transient changes in the environmental conditions from greenhouse to icehouse controlled by the onset of the major Antarctic glaciation phase (~34 Ma). The effects of this major climatic transition in Earth history have not been studied so far in the southern Tethys. Here, we present new data from the Ain Rahma section (Northeastern Tunisia, Cap Bon peninsula) across the Late Eocene—Early Oligocene. Calcareous nannofossil biostratigraphy permits an excellent detection of the paleoclimatic events of this transition. Hand-held X-ray Fluorescence (HH-XRF) analysis is used to show changes in detrital elements across the transition (Fe, Si, Al, Zr). Two major changes are recorded in the studied interval corresponding to the Eocene/Oligocene transition 1 event (EOT1) and to the Oi-1 glaciation event. Both depicted by important shifts in detrital elements and calcareous nannofossil assemblages.