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

ABSTRACT: 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.

SUBMITTER: Schmitz B

PROVIDER: S-EPMC6750910 | biostudies-literature | 2019 Sep

REPOSITORIES: biostudies-literature

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

Schmitz Birger B Farley Kenneth A KA Goderis Steven S Heck Philipp R PR Bergström Stig M SM Boschi Samuele S Claeys Philippe P Debaille Vinciane V Dronov Andrei A van Ginneken Matthias M Harper David A T DAT Iqbal Faisal F Friberg Johan J Liao Shiyong S Martin Ellinor E Meier Matthias M M MMM Peucker-Ehrenbrink Bernhard B Soens Bastien B Wieler Rainer R Terfelt Fredrik F

Science advances 20190918 9

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 <sup>3</sup>He 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 o ...[more]

PMID: 31555741

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

Publications

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

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