• journal_title：Geology
• Contributor：Paul A. Wilson ; Bradley N. Opdyke
• Publisher：Geological Society of America
• Date：1996-
• Format：text/html
• Language：en
• Identifier：10.1130/0091-7613(1996)024<0555:ESSTFT>2.3.CO;2
• journal_abbrev：Geology
• issn：0091-7613
• volume：24
• issue：6
• firstpage：555

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.