Publication Date:
2014-08-27
Description:
The Paleocene–Eocene Thermal Maximum (PETM), ca. 56 Ma, was a major global environmental perturbation attributed to a rapid rise in the concentration of greenhouse gases in the atmosphere. Geochemical records of tropical sea-surface temperatures (SSTs) from the PETM are rare and are typically affected by post-depositional diagenesis. To circumvent this issue, we have analyzed oxygen isotope ratios ( 18 O) of single specimens of exceptionally well-preserved planktonic foraminifera from the PETM in Tanzania (~19°S paleolatitude), which yield extremely low 18 O, down to 〈–5. After accounting for changes in seawater chemistry and pH, we estimate from the foraminifer 18 O that tropical SSTs rose by 〉3 °C during the PETM and may have exceeded 40 °C. Calcareous plankton are absent from a large part of the Tanzania PETM record; extreme environmental change may have temporarily caused foraminiferal exclusion.
Print ISSN:
0091-7613
Electronic ISSN:
1943-2682
Topics:
Geosciences