Onset of main Phanerozoic marine radiation sparked by emerging Mid Ordovician icehouse.

Forskningsoutput: TidskriftsbidragArtikel i vetenskaplig tidskrift

Abstract

The Great Ordovician Biodiversification Event (GOBE) was the most rapid and sustained increase in marine Phanerozoic biodiversity. What generated this biotic response across Palaeozoic seascapes is a matter of debate; several intrinsic and extrinsic drivers have been suggested. One is Ordovician climate, which in recent years has undergone a paradigm shift from a text-book example of an extended greenhouse to an interval with transient cooling intervals - at least during the Late Ordovician. Here, we show the first unambiguous evidence for a sudden Mid Ordovician icehouse, comparable in magnitude to the Quaternary glaciations. We further demonstrate the initiation of this icehouse to coincide with the onset of the GOBE. This finding is based on both abiotic and biotic proxies obtained from the most comprehensive geochemical and palaeobiological dataset yet collected through this interval. We argue that the icehouse conditions increased latitudinal and bathymetrical temperature and oxygen gradients initiating an Early Palaeozoic Great Ocean Conveyor Belt. This fuelled the GOBE, as upwelling zones created new ecospace for the primary producers. A subsequent rise in δ(13)C ratios known as the Middle Darriwilian Isotopic Carbon Excursion (MDICE) may reflect a global response to increased bioproductivity encouraged by the onset of the GOBE.

Detaljer

Författare
  • Christian Rasmussen
  • Clemens V Ullmann
  • Kristian G Jakobsen
  • Anders Lindskog
  • Jesper Hansen
  • Thomas Hansen
  • Mats Eriksson
  • Andrei Dronov
  • Robert Frei
  • Christoph Korte
  • Arne T Nielsen
  • David A T Harper
Enheter & grupper
Externa organisationer
  • University of Copenhagen
Forskningsområden

Ämnesklassifikation (UKÄ) – OBLIGATORISK

  • Geologi
Originalspråkengelska
Artikelnummer18884
TidskriftScientific Reports
Volym6
StatusPublished - 2016
PublikationskategoriForskning
Peer review utfördJa

Relaterad forskningsoutput

Anders Lindskog, 2017 feb, Lund: Lund University, Faculty of Science, Department of Geology, Lithosphere and Biosphere Science. 132 s.

Forskningsoutput: AvhandlingDoktorsavhandling (sammanläggning)

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