Temperate rainforests near the South Pole during peak Cretaceous warmth

The mid-Cretaceous period was one of the warmest intervals of the past 140 million years1,2,3,4,5, driven by atmospheric carbon dioxide levels of around 1,000 parts per million by volume6. In the near absence of proximal geological records from south of the Antarctic Circle, it is disputed whether polar ice could exist under such environmental conditions. Here we use a sedimentary sequence recovered from the West Antarctic shelf—the southernmost Cretaceous record reported so far—and show that a temperate lowland rainforest environment existed at a palaeolatitude of about 82° S during the Turonian–Santonian age (92 to 83 million years ago). This record contains an intact 3-metre-long network of in situ fossil roots embedded in a mudstone matrix containing diverse pollen and spores. A climate model simulation shows that the reconstructed temperate climate at this high latitude requires a combination of both atmospheric carbon dioxide concentrations of 1,120–1,680 parts per million by volume and a vegetated land surface without major Antarctic glaciation, highlighting the important cooling effect exerted by ice albedo under high levels of atmospheric carbon dioxide.

Details

Publication status:
Published
Author(s):
Authors: Klages, Johann P., Salzmann, Ulrich, Bickert, Torsten, Hillenbrand, Claus-Dieter ORCIDORCID record for Claus-Dieter Hillenbrand, Gohl, Karsten, Kuhn, Gerhard, Bohaty, Steven M., Titschack, Jürgen, Müller, Juliane, Frederichs, Thomas, Bauersachs, Thorsten, Ehrmann, Werner, van de Flierdt, Tina, Pereira, Patric Simões, Larter, Robert D. ORCIDORCID record for Robert D. Larter, Lohmann, Gerrit, Niezgodzki, Igor, Uenzelmann-Neben, Gabriele, Zundel, Maximilian, Spiegel, Cornelia, Mark, Chris, Chew, David, Francis, Jane E., Nehrke, Gernot, Schwarz, Florian, Smith, James A. ORCIDORCID record for James A. Smith, Freudenthal, Tim, Esper, Oliver, Pälike, Heiko, Ronge, Thomas A., Dziadek, Ricarda

On this site: Claus-Dieter Hillenbrand, James Smith, Jane Francis, Robert Larter
Date:
1 April, 2020
Journal/Source:
Nature / 580
Page(s):
81-86
Digital Object Identifier (DOI):
https://doi.org/10.1038/s41586-020-2148-5