Evidence for global cooling in the Late Cretaceous

• Published in: Nature communications Vol. 5; no. 1; p. 4194
• Main Authors: Linnert, Christian, Robinson, Stuart A., Lees, Jackie A., Bown, Paul R., Pérez-Rodríguez, Irene, Petrizzo, Maria Rose, Falzoni, Francesca, Littler, Kate, Arz, José Antonio, Russell, Ernest E.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 17-06-2014; Nature Publishing Group; Nature Pub. Group
• Subjects: 704/106/413; 704/106/829/2737; Humanities and Social Sciences; multidisciplinary; Science; Science (multidisciplinary)
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms5194

The Late Cretaceous ‘greenhouse’ world witnessed a transition from one of the warmest climates of the past 140 million years to cooler conditions, yet still without significant continental ice. Low-latitude sea surface temperature (SST) records are a vital piece of evidence required to unravel the cause of Late Cretaceous cooling, but high-quality data remain illusive. Here, using an organic geochemical palaeothermometer (TEX
86
), we present a record of SSTs for the Campanian–Maastrichtian interval (~83–66 Ma) from hemipelagic sediments deposited on the western North Atlantic shelf. Our record reveals that the North Atlantic at 35 °N was relatively warm in the earliest Campanian, with maximum SSTs of ~35 °C, but experienced significant cooling (~7 °C) after this to <~28 °C during the Maastrichtian. The overall stratigraphic trend is remarkably similar to records of high-latitude SSTs and bottom-water temperatures, suggesting that the cooling pattern was global rather than regional and, therefore, driven predominantly by declining atmospheric
p
CO
2
levels.
The Late Cretaceous experienced significant cooling, yet a lack of low-latitude records mean the regional extent of this cooling is poorly constrained. Linnert
et al.
present a TEX
86
sea surface temperature record from a palaeolatitude of ~35 °N and show that Late Cretaceous cooling was global in nature.