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.

Evidence for global cooling in the Late Cretaceous / C. Linnert, S.A. Robinson, J.A. Lees, P.R. Bown, I. Pérez Rodríguez, M.R. Petrizzo, F. Falzoni, K. Littler, J.A. Arz, E.E. Russell. - In: NATURE COMMUNICATIONS. - ISSN 2041-1723. - 5(2014 Jun 17), pp. 4194.1-4194.7. [10.1038/ncomms5194]

Evidence for global cooling in the Late Cretaceous

M.R. Petrizzo;F. Falzoni;
2014

Abstract

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.
biochemistry; geology; cretaceous; paleoceanography
Settore GEO/01 - Paleontologia e Paleoecologia
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2434/240292
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