par Schmitz, Birger;Farley, Kenneth K.A.;Goderis, Steven;Heck, Philipp R.;Bergström, Stig Magnus;Boschi, Samuele;Claeys, Philippe;Debaille, Vinciane ;Dronov, Andrei;Van Ginneken, Matthias ;Harper, D.A.T.;Iqbal, Faisal;Friberg, Johan;Liao, Shiyong;Martin, Ellinor;Meier, Matthias M.M.M.;Peucker-Ehrenbrink, Bernhard;Soens, Bastien ;Wieler, Rainer;Terfelt, Fredrik
Référence Science advances, 5, 9, eaax4184
Publication Publié, 2019-09
Référence Science advances, 5, 9, eaax4184
Publication Publié, 2019-09
Article révisé par les pairs
Résumé : | 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. |