Abstract

The classic paleotemperature record based on δ18O data from pelagic foraminiferal calcite suggests that equatorial sea-surface temperatures during the Maastrichtian (∼12–20 °C) were much cooler than today (∼27–29 °C). Such cool equatorial temperatures contradict basic theories of tropical atmospheric and ocean dynamics. We report δ18O data from remarkably well preserved rudist aragonite and magnesian calcite cements of Maastrichtian age (∼ 69 ± 1 Ma) from the carbonate platform of Wodejebato guyot in the western Pacific. These data suggest that equatorial sea-surface temperatures in the Maastrichtian (best estimate ∼ 27–32 °C) were at least as warm as today. This finding helps reconcile the geologic δ18O record with ocean-atmospheric dynamic theory and implies a reduction in the poleward heat flux required by global climate simulations of greenhouse conditions.

This content is PDF only. Please click on the PDF icon to access.

First Page Preview

First page PDF preview
You do not currently have access to this article.