Abstract
The Eocene-Oligocene transition (EOT; ca. 33-34 Ma) was a time of pronounced climatic change, marked by the establishment of continental-scale Antarctic ice sheets. The timing and extent of temperature change associated with the EOT is controversial. Here we present multiproxy EOT climate records (~15-34 k.y. resolution) from St. Stephens Quarry, Alabama, USA, derived from foraminiferal Mg/Ca, 18O, and TEX86. We constrain sea-surface temperatures (SSTs) in the latest Eocene and early Oligocene and address the issue of climatic cooling during the EOT. Paleotemperatures derived from planktic foraminifera Mg/Ca and TEX86 are remarkably consistent and indicate late Eocene subtropical SSTs of >28 °C. There was substantial and accelerated cooling of SSTs (3-4 °C) through the latest Eocene "precursor" 18O shift (EOT-1), prior to Oligocene Isotope-1 (Oi-1). Our multispecies planktic foraminiferal 18O records diverge at the E/O boundary (33.7 Ma), signifying enhanced seasonality in the earliest Oligocene in the Gulf of Mexico.
Original language | English (US) |
---|---|
Pages (from-to) | 159-162 |
Number of pages | 4 |
Journal | Geology |
Volume | 40 |
Issue number | 2 |
DOIs | |
State | Published - Feb 2012 |
All Science Journal Classification (ASJC) codes
- Geology