Evidence for global cooling in the Late Cretaceous

• Published in: Nature Communications
• Main Authors: C. Linnert, S. A. Robinson, J. A. Lees, P. R. Bown, I. Pérez Rodríguez, K. Littler, J. A. Arz, E. E. Russell, M.R. Petrizzo, F. Falzoni
• Other Authors: S.A. Robinson, J.A. Lee, P.R. Bown, J.A. Arz, E.E. Russell
• Format: Article in Journal/Newspaper
• Language: English
• Published: Nature publishing group 2014
• Subjects: biochemistry; geology; cretaceou; paleoceanography; Settore GEO/01 - Paleontologia e Paleoecologia; North Atlantic
• Online Access: http://hdl.handle.net/2434/240292; https://doi.org/10.1038/ncomms5194

The Late Cretaceous â ̃ greenhouseâ ™ 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 pCO 2 levels.