Physical Sciences Division
Published September 18, 2019 | Version v1
Journal article Open

An extraterrestrial trigger for the mid-Ordovician ice age: Dust from the breakup of the L-chondrite parent body

Creators

  • 1. Lund University
  • 2. California Institute of Technology
  • 3. Vrije Universiteit Brussel
  • 4. University of Chicago
  • 5. The Ohio State University
  • 6. Université Libre de Bruxelles
  • 7. Russian Academy of Sciences
  • 8. Royal Belgian Institute of Natural Sciences
  • 9. Durham University
  • 10. Chinese Academy of Sciences
  • 11. ETH Zürich
  • 12. Woods Hole Oceanographic Institution

Description

The breakup of the L-chondrite parent body in the asteroid belt 466 million years (Ma) ago still delivers almost a third of all meteorites falling on Earth. Our new extraterrestrial chromite and 3He data for Ordovician sediments show that the breakup took place just at the onset of a major, eustatic sea level fall previously attributed to an Ordovician ice age. Shortly after the breakup, the flux to Earth of the most fine-grained, extraterrestrial material increased by three to four orders of magnitude. In the present stratosphere, extraterrestrial dust represents 1% of all the dust and has no climatic significance. Extraordinary amounts of dust in the entire inner solar system during >2 Ma following the L-chondrite breakup cooled Earth and triggered Ordovician icehouse conditions, sea level fall, and major faunal turnovers related to the Great Ordovician Biodiversification Event.

Data availability

All data needed to evaluate the conclusions in the paper are present in the paper and/or the Supplementary Materials. Additional data related to this paper may be requested from the authors.

Files

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Additional details

Identifiers

DOI
10.1126/sciadv.aax4184
Other
oai:uchicago.tind.io:11045

Funding

European Research Council

UChicago Information

Division(s)
Physical Sciences Division
Department(s)
Geophysical Sciences