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

Summary, in English

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.

• Author: Birger Schmitz; Kenneth A. Farley; Steven Goderis; Philipp R. Heck; Stig M. Bergström; Samuele Boschi; Philippe Claeys; Vinciane Debaille; Andrei Dronov; Matthias van Ginneken; David A.T. Harper; Faisal Iqbal; Johan Friberg; Shiyong Liao; Ellinor Martin; Matthias M.M. Meier; Bernhard Peucker-Ehrenbrink; Bastien Soens; Rainer Wieler; Fredrik Terfelt
• Department/s: Nuclear physics; MERGE: ModElling the Regional and Global Earth system
• Publishing year: 2019-09-18
• Language: English
• Publication/Series: Science Advances
• Volume: 5
• Issue: 9
• Links: http://dx.doi.org/10.1126/sciadv.aax4184
• Document type: Journal article
• Publisher: American Association for the Advancement of Science (AAAS)
• Topic: Geology
• Status: Published
• ISBN/ISSN/Other: ISSN: 2375-2548