Articles | Volume 13, issue 9
Biogeosciences, 13, 2859–2872, 2016
Biogeosciences, 13, 2859–2872, 2016

Research article 13 May 2016

Research article | 13 May 2016

Equatorward phytoplankton migration during a cold spell within the Late Cretaceous super-greenhouse

Niels A. G. M. van Helmond1, Appy Sluijs1, Nina M. Papadomanolaki1, A. Guy Plint2, Darren R. Gröcke3, Martin A. Pearce4, James S. Eldrett5, João Trabucho-Alexandre3,6, Ireneusz Walaszczyk7, Bas van de Schootbrugge1, and Henk Brinkhuis1,8 Niels A. G. M. van Helmond et al.
  • 1Marine Palynology and Paleoceanography, Laboratory of Palaeobotany and Palynology, Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Heidelberglaan 2, 3584 CS Utrecht, the Netherlands
  • 2Department of Earth Sciences, The University of Western Ontario, London, Ontario N6A 5B7, Canada
  • 3Department of Earth Sciences, Durham University, South Road, Durham DH1 3LE, UK
  • 4Evolution Applied Ltd, 50 Mitchell Way, Upper Rissington, Cheltenham, Gloucestershire GL54 2PL, UK
  • 5Shell International Exploration and Production Inc., Kesslerpark 1, 2288 GS Rijswijk, the Netherlands
  • 6Comparative Sedimentology Group, Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Heidelberglaan 2, 3584 CS Utrecht, the Netherlands
  • 7Institute of Geology, Faculty of Geology, University of Warsaw, Zwirki I Wigury 93, 02-089 Warsaw, Poland
  • 8NIOZ, Royal Netherlands Institute for Sea Research, P.O. Box 59, 1790 AB Den Burg, Texel, the Netherlands

Abstract. Oceanic Anoxic Event 2 (OAE2), a  ∼  600 kyr episode close to the Cenomanian–Turonian boundary (ca. 94 Ma), is characterized by relatively widespread marine anoxia and ranks amongst the warmest intervals of the Phanerozoic. The early stages of OAE2 are, however, marked by an episode of widespread transient cooling and bottom water oxygenation: the Plenus Cold Event. This cold spell has been linked to a decline in atmospheric pCO2, resulting from enhanced global organic carbon burial. To investigate the response of phytoplankton to this marked and rapid climate shift we examined the biogeographical response of dinoflagellates to the Plenus Cold Event. Our study is based on a newly generated geochemical and palynological data set from a high-latitude Northern Hemisphere site, Pratts Landing (western Alberta, Canada). We combine these data with a semi-quantitative global compilation of the stratigraphic distribution of dinoflagellate cyst taxa. The data show that dinoflagellate cysts grouped in the Cyclonephelium compactum–membraniphorum morphological plexus migrated from high to mid-latitudes during the Plenus Cold Event, making it the sole widely found (micro)fossil to mark this cold spell. In addition to earlier reports from regional metazoan migrations during the Plenus Cold Event, our findings illustrate the effect of rapid climate change on the global biogeographical dispersion of phytoplankton.

Short summary
Over the past decades large changes have been observed in the biogeographical dispersion of marine life resulting from climate change. To better understand present and future trends it is important to document and fully understand the biogeographical response of marine life during episodes of environmental change in the geological past. Here we investigate the response of phytoplankton, the base of the marine food web, to a rapid cold spell, interrupting greenhouse conditions during the Cretaceous.
Final-revised paper