Evidence for global cooling in the Late Cretaceous
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...
Published in: | Nature Communications |
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Main Authors: | , , , , , , , , , |
Other Authors: | , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Nature publishing group
2014
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Subjects: | |
Online Access: | http://hdl.handle.net/2434/240292 https://doi.org/10.1038/ncomms5194 |
Summary: | 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. |
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